EP2734334A1 - A grinding tool for machining brittle materials and a method of making a grinding tool - Google Patents

A grinding tool for machining brittle materials and a method of making a grinding tool

Info

Publication number
EP2734334A1
EP2734334A1 EP12817725.0A EP12817725A EP2734334A1 EP 2734334 A1 EP2734334 A1 EP 2734334A1 EP 12817725 A EP12817725 A EP 12817725A EP 2734334 A1 EP2734334 A1 EP 2734334A1
Authority
EP
European Patent Office
Prior art keywords
grinding tool
bonding agent
matrix
abrasive
volume
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP12817725.0A
Other languages
German (de)
French (fr)
Other versions
EP2734334A4 (en
EP2734334B1 (en
Inventor
Michael THOLIN
Fredrik WESTBERG
Stefan BERGH
Ida JOHANSSON
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
3M Innovative Properties Co
Original Assignee
Slipnaxos AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Slipnaxos AB filed Critical Slipnaxos AB
Publication of EP2734334A1 publication Critical patent/EP2734334A1/en
Publication of EP2734334A4 publication Critical patent/EP2734334A4/en
Application granted granted Critical
Publication of EP2734334B1 publication Critical patent/EP2734334B1/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D3/00—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents
    • B24D3/02—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent
    • B24D3/04—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent and being essentially inorganic
    • B24D3/06—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent and being essentially inorganic metallic or mixture of metals with ceramic materials, e.g. hard metals, "cermets", cements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D3/00—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents
    • B24D3/02—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent
    • B24D3/04—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent and being essentially inorganic
    • B24D3/06—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent and being essentially inorganic metallic or mixture of metals with ceramic materials, e.g. hard metals, "cermets", cements
    • B24D3/08—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent and being essentially inorganic metallic or mixture of metals with ceramic materials, e.g. hard metals, "cermets", cements for close-grained structure, e.g. using metal with low melting point
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/18—Non-metallic particles coated with metal
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D18/00—Manufacture of grinding tools or other grinding devices, e.g. wheels, not otherwise provided for
    • B24D18/0009—Manufacture of grinding tools or other grinding devices, e.g. wheels, not otherwise provided for using moulds or presses
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D3/00—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents
    • B24D3/02—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent
    • B24D3/20—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent and being essentially organic
    • B24D3/22—Rubbers synthetic or natural
    • B24D3/24—Rubbers synthetic or natural for close-grained structure
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D3/00—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents
    • B24D3/02—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent
    • B24D3/20—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent and being essentially organic
    • B24D3/28—Resins or natural or synthetic macromolecular compounds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D3/00—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents
    • B24D3/34—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents characterised by additives enhancing special physical properties, e.g. wear resistance, electric conductivity, self-cleaning properties
    • B24D3/342—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents characterised by additives enhancing special physical properties, e.g. wear resistance, electric conductivity, self-cleaning properties incorporated in the bonding agent
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D5/00—Bonded abrasive wheels, or wheels with inserted abrasive blocks, designed for acting only by their periphery; Bushings or mountings therefor
    • B24D5/02—Wheels in one piece
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D5/00—Bonded abrasive wheels, or wheels with inserted abrasive blocks, designed for acting only by their periphery; Bushings or mountings therefor
    • B24D5/06—Bonded abrasive wheels, or wheels with inserted abrasive blocks, designed for acting only by their periphery; Bushings or mountings therefor with inserted abrasive blocks, e.g. segmental
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D7/00—Bonded abrasive wheels, or wheels with inserted abrasive blocks, designed for acting otherwise than only by their periphery, e.g. by the front face; Bushings or mountings therefor
    • B24D7/06—Bonded abrasive wheels, or wheels with inserted abrasive blocks, designed for acting otherwise than only by their periphery, e.g. by the front face; Bushings or mountings therefor with inserted abrasive blocks, e.g. segmental
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D99/00—Subject matter not provided for in other groups of this subclass
    • B24D99/005—Segments of abrasive wheels
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C26/00—Alloys containing diamond or cubic or wurtzitic boron nitride, fullerenes or carbon nanotubes
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C32/00—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ
    • C22C32/0047—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with carbides, nitrides, borides or silicides as the main non-metallic constituents
    • C22C32/0068—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with carbides, nitrides, borides or silicides as the main non-metallic constituents only nitrides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
    • B22F2998/10—Processes characterised by the sequence of their steps

Definitions

  • the invention relates to a grinding tool, in particular a grinding tool for grinding hard and/or brittle materials such as tungsten carbide.
  • the grinding tool may in particular be a grinding wheel.
  • the invention also relates to a method of making such a grinding tool.
  • Grinding tools such as grinding wheels are used for machining of brittle materials.
  • One area where such grinding tools are used is machining of tools that are made of hard metal (tungsten carbide).
  • grinding tools may be used for machining operations in which drills or milling tools are shaped by grinding.
  • the abrasive tool must have abrasive particles of a very hard material. In practice, this normally means that the abrasive particles are diamond particles or grains of cubic boron nitride. Diamonds or cubic boron nitride grains for this purpose are commercially available and can be considered as standard components. Diamonds for this purpose may typically have an average or mean particle size of 50 ⁇ (the size of the particles is of course varying) and have a plurality of sharp edges that can cut hard materials such as tungsten carbide.
  • a known type of grinding tool for this purpose is a grinding wheel with a core which may be made of, for example, a metallic material such as steel or aluminum.
  • the core may also be made of a non-metallic material such as a polymeric material.
  • the core can be shaped as a disc which can be mounted on a tool spindle for rotation about the axis of the disc-shaped metal core.
  • An abrasive rim surrounds the core and is joined to the core.
  • the abrasive rim may comprise abrasive particles embedded in a matrix with one or more bonding agents.
  • the material used in the abrasive rim is normally more expensive than the material of the core.
  • the abrasive rim has a smaller extension in the radial direction than the core (i.e. the abrasive rim is normally a smaller part of the grinding wheel since it is more expensive).
  • the abrasive rim is gradually worn down until it is consumed and the grinding wheel can no longer be used.
  • Known bonding agents for abrasive rims of grinding wheels include polymeric b agents such as, for example, Bakelite.
  • the bonding agent may be a ceramic bonding agent.
  • metallic bonding agents in particu bonding agents of bronze that have been made by sintering.
  • bronze compositions for this purpose include copper/tin/cobalt (Cu/ and copper/tin/nickel (Cu/Sn/Ni). It has also been suggested that bronze composit for this purpose may include copper/tin/titanium (Cu/Sn/Ti).
  • Yet another known system includes hybrids of polymeric and metallic bonding a£ in which metallic powder is sintered together with polymeric material such that a is formed in which the polymeric bonding agent and the metallic bonding agent (typically a bronze alloy as described above) are closely intertwined with each otl a microscopic level. In such hybrids, the metal bonding agent and the polymeric bonding agent each forms a network and the respective networks of the bonding a penetrate each other.
  • Such a hybrid matrix that comprises both a metal bonding a ⁇ and a polymeric bonding agent is disclosed in for example US patent No. 606314
  • such hybrids normally inch one or several fillers.
  • One such filler may be graphite which is used for its lubrica properties.
  • the abrasive particles used may have different properties.
  • the brittk of diamonds may vary depending on the purpose for which the grinding tool is to used.
  • the properties of different diamonds may be matched to meet the properties different bonding agents (or hybrids of bonding agents).
  • the abrasive particles should be bonded in its matrix in su way that the grinding tool functions as desired. It is desirable that the grinding toe a good resistance to wear such that it can be used over an extended period. Howe 1 good wear resistance is not the only desired property and the grinding tool with tt highest resistance to wear is not necessarily the best choice.
  • Other desirable propt include low energy consumption (i.e.
  • the extent of wear of the grinding tool under given circumstances depends to a v ⁇ high degree on the properties of the matrix in which the abrasive particles are embedded. Therefore, the composition of the matrix is important.
  • the abrasive particles act on the work piece. Thereby, force is exerted on abrasive particles embedded in the matrix. During the grinding, the abrasive particles are damaged. Gradually, small pieces break loose from the abrasive particles such th abrasive particles are gradually worn down. When the abrasive particles in one ar the abrasive rim have been completely worn down, the work piece meets the mati directly. The matrix as such is less hard than the work piece and it is quickly won down. As a result, fresh abrasive particles come to the surface of the abrasive rim can start to act on the work piece.
  • abrasive parti may be torn away from the matrix before they have been worn down.
  • the work piece will come into c contact with the relatively brittle matrix and wear down the matrix prematurely. This happens, power consumption drops momentarily until so much of the matrix been worn down that fresh abrasive particles come to the surface.
  • the abrasive rim of the grinding tool is worn out faster than it would otherwise have b the operation of the grinding tool has been programmed in advance, the conseque thereof may be that the grinding operation does not function properly since the gr tool is set to operate based on an assumption of tool diameter that is now incorrec problem becomes more serious if the abrasive rim is worn out in a way that is difi to predict, for example if wear occurs in sudden stens that come in irreeular inten It is also desirable that the required power for the grinding operation can be kept 1 such that the energy consumption during grinding can be minimized. Another desirable property of grinding tools is a high G-ratio.
  • the G-ratio expres; ratio between the volume of the material removed by the grinding tool from a wo: piece and the volume lost by the grinding tool (the wear on the tool).
  • a good grin tool has a high G-ratio. Therefore, it is an object of the present invention to provide a grinding tool that h; good resistance to wear. Further objects of the invention are to provide a tool that worn out in a regular and predictable way, which has a low power requirement an high G-ratio.
  • the invention relates to a grinding tool.
  • the grinding tool is especially intended a grinding tool for machining hard and/or brittle materials, such as tungsten carbide the inventive grinding tool could also be used for grinding other materials.
  • the gr tool comprises a core and an abrasive rim.
  • the abrasive rim comprises abrasive p embedded in a matrix and the matrix comprises a metallic bonding agent which is sintered bronze alloy.
  • the metallic bonding agent constitutes 50 % - 100 % by vo of the matrix.
  • the metallic bonding agent contains sili nitride in an amount that constitutes 0.02 % - 5.0 % by volume of the metallic bot agent or optionally 0.1 % by volume - 5.0 % by volume of the metallic bonding a
  • the matrix may further optionally comprise a polymeric bonding agent that has been sintered together with the metallic bondinj such that the polymeric bonding agent and the metallic bonding agent form a com network.
  • the silicon nitride constitutes 0.3 % - 5.0 % by - ⁇ of the metallic bonding agent.
  • it may constitute 0.5 % - 5.0 % by vo of the metallic bonding agent, 1.0 % - 5.0 % by volume of the metallic bonding a or 0.5 % - 3.0 % by volume or 0.5 % - 2.0 % by volume.
  • the silicon nitride may be present in the shape of grains having an average grain which is preferably less than ⁇ but also preferably above ⁇ . ⁇ . Such particli be 1250 Tyler mesh particles. The particles may thus include particles up to ⁇ though average grain size is smaller.
  • the polymeric bonding age comprise polyimide or be made entirely or almost entirely of polyimide.
  • the matrix may optionally additionally comprise filler materials such as graphite.
  • Filler materials such as graphite.
  • Graphite has lubricating properties which may be desirable during grinding.
  • the metallic bonding agent is preferably a bronze alloy that comprises copper, tin silver.
  • the abrasive particles may be, for example, diamond particles or cubic boron nitr particles. For both diamonds and cubic boron nitride, the abrasive particles may h mean particle size in the range of 4 ⁇ - 18 ⁇ . In many realistic embodiments, abrasive particles may have a size in the range of 46 ⁇ - 91 ⁇ . In embodiments invention, the abrasive particles may have a coating of copper or nickel.
  • the invention also relates to a method of making the inventive grinding tool.
  • the method comprises sintering abrasive particles together with metallic powder such the sintering results in a matrix in which the abrasive particles are embedded.
  • the matrix will thereby comprise a metallic bonding agent.
  • the metallic powder com] copper and tin such that the metallic bonding agent will be a sintered bronze allo
  • silicon nitride in the form of a powder is added to the metallic powder before sintering and to such an extent that the silicon nitride will constitute 0.02 % - 5.0 % by volume of the metallic bonding agent and preferably - 5.0% by volume of the metallic bonding agent.
  • the metallic powder may additionally comprise silver.
  • the relative proportion of silicon nitride in the metal bi agent refers to the volume proportion of the pow used in the manufacturing process.
  • the method of manufacturing i that, in the powder added before sinterine. silicon nitride will constitute 0.02 % - by volume of the metallic bonding agent (the silicon nitride being counted as part metal bonding agent). It is assumed that the silicon carbide particles will retain th relative proportion of total volume also after sintering.
  • a polymer is added to the metallic powder before sintering, preferabl ⁇ form of polyimide powder, such that also a polymeric bonding agent is formed wl a part of the matrix.
  • the method may be carried out in such a way that the powder material for the bot agents of the matrix is mixed with the abrasive particles to form a mixture.
  • the m is then compacted in a cold press.
  • the compacted mixture is then cured in a kiln ⁇ temperature in the range of 380°C - 520°C, preferably 400°C - 500°C, for a perio 120 - 150 minutes.
  • the compacted and cured mixture is placed in a pri subjected to a pressure of 1500 - 2000 kg/cm 2 . The pressure is then held until the mixture has reached a temperature below 300°C.
  • filler material is added to the mixture of metallic powder and abrasive particles before the sintering operation.
  • the filler material may optionally compri graphite.
  • the matrix of the inventive grinding tool may advantageously be a matrix which : hybrid, i.e. a matrix having both a metal bonding agent and a polymeric bonding ; Hybrid bonding solutions can combine the best properties of metal bonding agent the best properties of polymeric bonding agents. If re-sharpening by a sharpening needed, a grinding tool with a hybrid matrix can be re-sharpened easier than a530 metal matrix. At the same time, a grinding tool with a hybrid matrix has better resistance to wear than a matrix using only a polymeric bonding agent.
  • Figure 1 is a schematic representation of a grinding tool.
  • Figure 2 is a schematic cross sectional representation of abrasive particles embedded in the abrasive rim of a grinding tool.
  • Figure 3 is a schematic cross sectional representation of a grinding tool that z
  • Figure 4 is a diagram that represents the power consumption for two differen grinding tools.
  • Figure 5 is a schematic cross sectional representation of a first embodiment c inventive grinding tool.
  • Figure 6 is a schematic cross sectional representation of a second embodimer the inventive grinding tool.
  • Figure 7 is a diagram that shows wear of a grinding tool as a function of silic nitride content.
  • Figure 8 is a diagram that shows the G-ration of a grinding tool as a function silicon nitride content.
  • the grinding tool may in particular be a grinding wheel which is intended for machining hard and/or brittle materials such as tungsten carbide. Such materials may be present in work pieces tools such as for example drills or milling tools and the grinding tool 1 of the pres invention may be a grinding wheel that is used for shaping such tools.
  • the grindii 1 comprises a core 2 and an abrasive rim 4.
  • the core 2 may be made of a less exp material such as steel or some other metal.
  • the core could be made example, a polymeric material.
  • the core could also comprise more than one mate For example, it could be made partially by metal such as steel or aluminum and p be a polymeric material.
  • the core 2 may be provided with a through-hole or cavit such that the grinding tool 1 may be mounted on a spindle (not shown) for rotary movement.
  • the abrasive rim 4 comprises abrasive pari embedded in a matrix 6.
  • the matrix 6 in turn comprises a metallic bonding agent is a sintered bronze alloy.
  • the metallic bonding agent constitutes 50 % - 100 % b; volume of the matrix 6 and embodiments are thus conceivable in which the entire matrix 6 is made up of the metallic bonding agent.
  • the matrix 6 normal! comprises at least some other component. For example, it may comprise filler sue graphite that has lubricating properties.
  • the matrix 6 would comprise a polymeric bonding agent that may be formed by polyimide.
  • the matrix 6 holds the abrasive particles 5 well, the abrasive particles 5 will em small fragments and be worn down gradually. As a result, the wear on the abrasiv 4 will be relatively slow such that the diameter of the grinding tool 1 can be kept substantially constant during a longer period. Moreover, wear on the abrasive rim be kept at an even pace and the power during operation will not vary so much. If the matrix 6 is instead incapable of holding the abrasive particles 5 firmly, it mi happen that abrasive particles come loose well before they have been fragmented, consequence, they will be lost before their entire abrasive potential has been used abrasive tool 1 will be worn out faster and the diameter of the grinding tool (such grinding wheel) will decrease faster. A smaller diameter of the grinding tool 1 ma result in a less accurate machining of the work pieces.
  • a grinding tool 1 acts on a work piece 7.
  • the work pie may be, for example, a work piece that shall be shaped to a drill.
  • the grinding toe rotated by means of a power source acting through for example a spindle (not sho Thereby, the abrasive rim 4 of the grinding tool acts on the work piece 7 to cut a ⁇ in the work piece.
  • the work piece has a core diameter CD which is determined by the action of the grinding tool 1. If the grinding tool 1 is worn dow that its diameter decreases, the core diameter CD will grow unless the wear is compensated (for example by repositioning of the grinding tool 1 in relation to th piece 7). It is therefore very desirable that the wear can be kept low and that the w that does take place does not come in sudden unpredictable leaps.
  • the abrasive particles 5 when the abrasive particles 5 are properly fragmented piece 1 piece, this is good for the free-cutting properties of the grinding tool 1, i.e. the abi the grinding tool to re-sharpen itself.
  • the abrasive particles 5 become fragm step by step, the wear on the matrix 6 can occur smoothly and the surface of the abrasive rim 4 does not become clogged so easily. If abrasive particles are insteac away suddenly before they have been properly fragmented, this tends to lead to increased clogging of the surface; the surface of the abrasive rim 4 may become c to a greater extent by small particles 5 from the work piece 7.
  • abrasive particles 5 may come to surface in a smoother process which in itself contributes to re-sharpening of the grinding tool (or rather the abrasive rim 4 of tt grinding tool 1).
  • the inventors of the present invention have considered what steps can be taken tc improve the ability of the matrix to hold the abrasive particles. Without wishing fc bound by theory, the inventors believe that one reason that metal bonding agents 1 the abrasive particles embedded therein may be that dislocations inside the metal bonding agent weaken the metallic bonding agent. Assuming this theory to be coi the inventors first speculated that it should be possible to improve the matrix by reinforcing it with particles blocking dislocations in the metal bonding agent.
  • the inventors tried different additions to the metal powder that was for sintering the metal bonding agent.
  • One additive that was tried was aluminum ⁇ which was added to an extent corresponding to 1.0 % by volume of the metal bon agent. This resulted in a certain improvement but the improvement was not as goc the inventors had hoped.
  • the inventors also tried addition of 0.01 % by volume oi silicon nitride. The improvement of that addition was even less than the improver achieved by the aluminum oxide.
  • silicon nitride was added in quantities significantly larger than 0.01 % by volume metal bonding agent, it was discovered that a very substantial improvement was obtained.
  • the inventors tested a composition in which the metal bonding agen contained 1.0 % by volume of silicon nitride (S1 3 N 4 ). A grinding tool with this composition was then comnared to a standard erindine tool usine a hvbrid matrix which did not contain silicon nitride (Si 3 N 4 ).
  • the grinding tools were both grindii wheels in which the abrasive rim 4 was shaped as a ring surrounding the core 2.
  • the diameter of the standard tool was worn down by 136 ⁇ while the diameter of the grinding tool with the experimental composition was w( down by only 58 ⁇ .
  • the G-ratio for the tool with 1.0 % silicon nitride was 2335. comparison, a tool using 0.01 % by volume of silicon nitride was worn down 94 ⁇ while a tool using 1.0 % by volume aluminum oxide was worn down 84 ⁇ .
  • the resistance to wear was still good but not quite as go for the grinding tool with 1.0% by volume silicon nitride.
  • the tool with silicon nitride had higher power consumption.
  • the G-ratio was good but not quite good as for the tools with 1.0% and 0.1 % by volume.
  • the inventors have also tested a grinding wheel which had a shape and a composi similar to the other tools tested but in which the silicon nitride constituted 0.1 % 1 volume of the metal bonding agent.
  • the inventors have also tested a grinding wheel which had a silicon nitride conter 0.02 % by volume of the metal bonding agent but which was otherwise similar to other grinding wheels tested. Under similar test conditions, the grinding wheel wi % by volume of silicon nitride has a wear (diameter reduction) of 58 ⁇ and a G-i 2283. The results were thus slightly better than the results obtained at a ratio of 0. by volume. The results lead to the conclusion that significantly better results are obtained in tl range of 0.02 % - 5.0 % by volume silicon nitride (S1 3 N 4 ). In this range, both G-n and resistance to wear has been found to be significantly better than at 0% or 0.01
  • Tests of resistance to wear and test of G-ratio have been carried out at 0 % by vol 0.01 % by volume, 0.02 % by volume, 1.0 % by volume and 5.0 % by volume sili nitride.
  • the tools that were tested were grinding wheels of substantially the kind shown ii Figure 5, i.e. grinding tools with an abrasive rim 4 that surrounds a core 2 and wh grinding tool 1 rotates about the axis A during operation.
  • Resistance to wear as a function of silicon nitride content can be seen in Figure 7.
  • the resistance to wear expressed in Figure 7 as diameter reduction.
  • resistanc wear increased significantly when the content of silicon nitride was increased froi % to 0.02 %.
  • the wear resistance continued to be high up to a silicon nitride cont 5.0 % by volume of the metallic bonding agent. However, at 5.0 % by volume sili nitride, the resistance to wear was somewhat lower compared to the resistance ob; at a content of 0.02 % - 1.0 %. The inventors have therefore concluded that the be wear resistance is obtained in the range of 0.02 % - 5.0 % by volume.
  • the G-ratio as a function of silicon nitride content can be seen in Figure 8. As cai seen in the figure, the best values are obtained at a silicon nitride content in the ra 0.02 % - 5.0%. From Figure 8, it can also be derived that the G-ratio is sinking to the right in the figure even though the G-ratio at 5.0% by volume is still good.
  • the metallic bonding agent may conl silicon nitride in an amount that constitutes 0.02 % - 5.0 % by volume of the mete bonding agent. Since power consumption was higher at 5.0 % by volume, the inv have concluded that values lower than 5.0% will have good resistance to wear bui power consumption compared to tools with a silicon nitride content of 5% by voli Therefore, a preferred range may be 0.02 % by volume to 3.0% by volume, 0.5 % % by volume, 0.5 % - 2.0 % by volume or 1.0 % - 2.0 % by volume of the metalli bonding agent.
  • the silicon nitride particles should preferably have a size up to ⁇ (1250 Tylei mesh). For sieved particles, this will normally mean that average grain size is less ⁇ .
  • the average particle size (D50) of the silicon nitride particles may then be 2 ⁇ - 3 ⁇ (depending on how average particle size is measured).
  • the specific su area of the silicon nitride particles may advantageously be in the range of 5 m 2 /g - m 2 /g. If the particles used are too small, this mav result in cloeeine and difficultie during manufacturing.
  • particles up to ⁇ should preferably b included.
  • the matrix 6 should further comprise a polymeric bonding agent that h ⁇ sintered together with the metallic bonding agent such that the polymeric bonding and the metallic bonding agent form a connected network (even though such a polymeric bonding agent is optional).
  • a polymeric bonding agent makes it poss fine tune the properties of the matrix and adapt it to different kinds of abrasive pa
  • the polymeric bonding agent may suitably be polyimide or comprise polyimide. ' reason for this is that polyimide is heat resistant and can withstand the high temperatures during sintering. If a polymeric bonding agent is used, the polymieri bonding agent may be present in an amount of up to 50% by volume of the matri? the amount of polymeric bonding agent is in the range of 0% - 50% by volume of matrix). For example, the polymeric bonding agent may represent 10 % - 40 % oi 30% by volume of the matrix.
  • the polymeric bonding agent could be formed by some other polymeric material.
  • it could be formed by polyamide-imide which is also capa withstanding high temperatures.
  • polyimide is preferred since it has bett grinding properties than polyamide-imide.
  • the metallic bonding agent is a preferably a bronze alloy that comprises copper, t silver. Silver improves the desirable properties of the metal bonding agent.
  • the abrasive particles 5 may be either diamond particles or cubic boron nitride p ⁇ Diamonds are harder and have better abrasive properties but cubic boron nitride i: temperature resistant. Moreover, diamonds may react chemically with certain ma1
  • the abrasive particles 5 may be are diamond particles or particles of cubic boron nitride. The particles may be in the range of 4 ⁇ - 18 ⁇ even though particles c this range may be considered depending on the requirements in each specific case many realistic embodiments, the abrasive particles 5 may have a mean particle si the range of 46 ⁇ - 91 ⁇ which is a range that is suitable for many grinding operations.
  • the abrasive particles 5 may optionally have a coating of copper or nickel. A coa copper or nickel can improve the bond between the abrasive particles 5 and the m 6. However, the abrasive properties of the particles 5 will be somewhat reduced ii particles have such a coating.
  • the relative proportion of abrasive particles 5 in relation to the bonding agents an fillers in the matrix 6 may vary depending on the requirements in each case.
  • the amount of abrasive particles may represent a 10 % - 5( the total volume of the abrasive rim (i.e. the total volume of the abrasive particles the matrix). If the relative proportion of abrasive particles is higher than 50 %, tt substantial danger that the matrix will no longer be able to hold the abrasive partii the relative proportion of abrasive particles is less than 10 %, the grinding effect r become too small.
  • the relative proportion of abrasive particles may preferably be range of 15 % - 30 % and a suitable value may be 25 %.
  • the silicon nitride is present in the shape of grains having an average £ size which is equal to or less than ⁇ but above 0.1 ⁇ .
  • they may a mean size in the range of ⁇ ⁇ - ⁇ or 2 ⁇ - 9 ⁇ . It is believed by the inver that silicon nitride particles smaller than 0.1 ⁇ may result in clogging of the silic nitride particles which reduces their reinforcing effect.
  • the silicon nitride particles may have three different crystallographic structures designated as ⁇ , ⁇ and ⁇ phases (also known as trigonal phase, hexagonal phase ai cubic phase).
  • the a and ⁇ phases are the most common.
  • the ⁇ phase can only be synthesized under high pressure and high temperature. Any of these phases can b ⁇
  • the phase used is the a phase.
  • the silicon nitride particles added may ; a mixture of particles of different phases.
  • a grinding tool according to the invention is comparec a standard grinding tool.
  • the vertical axis represents power consumption while th horizontal axis represents number of work pieces upon which the respective grind tool has acted.
  • B5 represents a grinding tool according to the inventic while EZ represents a standard grinding tool.
  • the tool represented as B5 has a power consumption that first rises steeply and thereafter remains substantially constant.
  • the conventional tool as represented by EZ has a consumption that rises steeply and then suddenly drops before it rises again. This indicates that the abrasive narticles of the B5 tool are slowlv fragmented while ⁇ / represents a grinding tool where the abrasive particles are suddenly torn away. Tr on the tool will therefore be faster.
  • B5 represents a tool with both a metal bonding agent and a polymeric bonding agent.
  • the metal bonding agent is a bronze that has copper, til silver. It has been sintered using a metal powder that contains 45 % by volume co 45 % by volume tin and 10 % by volume silver.
  • the polymeric bonding agent constitutes 1.0 % by volume of the total amount of bone agent.
  • the grinding tool of Figure 1 may have a cross section as shown in Figure 5.
  • the abrasive rim 4 is placed radially outside the core 2 such that the completely surrounds the core 2.
  • the tests explained with reference to Figure 4, 1 7 and Figure 8 have been carried out on such a grinding tool.
  • the invenl not limited to such an embodiment.
  • the core 2 may extend at least as much in the radial direction as the abrasive i
  • the grinding tool has an abrasive rim 4 that does not extend beyond tl 2 in the radial direction.
  • the abrasive rim 4 has an extension in the axial direction that is different from that of the core 2 (the axial direction being the axis rotation A of the grinding tool 1 when it is driven by a spindle, see Figure 5 and F 6). It should also be understood that the grinding tool 1 is not necessarily designei rotation. Instead, it could act on work pieces in a reciprocating movement.
  • the term "core” should thus be understood broadly as any k carrier body for the abrasive rim.
  • the term “rim” should also be underst broadly as any kind of layer secured to the core 2 such that abrasive particles can a work piece.
  • the invention further comprises a method of making the inventive grinding tool, method comprises sintering abrasive particles together with metallic powder that comprises copper and tin such that the sintering results in a matrix in which the al particles 5 are embedded.
  • the matrix comprises a metallic bonding agent which i; sintered bronze alloy.
  • silicon nitride in the form of a j is added to the metallic powder before sintering to such an extent that the silicon i will constitute 0.1% - 5.0% by volume of the metallic bonding agent.
  • the metal powder used is preferably metal powder with particles that are smaller 44 ⁇ but they should nreferablv be lareer than the silicon nitride narticles. Prefer they should be at least twice as large. An average size in the range of 15 ⁇ - 44 ⁇ be suitable.
  • the metallic powder may optionally also comprise silver.
  • the metal powder may come in the shape of pre-alloyed particles or as particles c copper, pure tin, pure silver etc.
  • a polymer may be added to the metallic powder before sintering, preferably in th of polyimide powder, such that also a polymeric bonding agent is formed which i part of the matrix 6.
  • the sintering method may be carried out such that the powder material for the boi agents of the matrix 6 is mixed with the abrasive particles 5.
  • the mixture is comp in a cold press.
  • the compacted is mixture is cured in a kiln at a tempen the range of 380°C - 520°C, preferably 400°C - 500°C or 440°C - 460°C, for a pe 120 - 150 minutes.
  • the time required depends on size. In a larger press form, mo is required.
  • the compacted and cur mixture is placed in a press and subjected to a pressure of 1500 - 2000 kg/cm 2 Tt pressure is then maintained until the mixture has reached a temperature below 30 ⁇
  • the abrasive rim 4 may also be manufactured by means of spark plasma sintering (SPS). By this technique, the abrasive rim 4 may be manufactured very fast.
  • SPS spark plasma sintering
  • the rim with the matrix containing abrasive particles may be sintered separately ⁇ subsequently fastened (e.g. glued) onto the core 2.
  • the abrasive rim be sintered directly onto the core 2 such that it is bonded to the core as it is forme
  • the core 2 may be electrolytically plated with copper on at least surface of the core which will meet the abrasive rim 4.
  • the abrasive rim 4 can the sintered onto the copper-plated surface such that a seam is formed.
  • Filler material may optionally be added to the mixture of metallic powder and abi particles 5 before the sintering operation.
  • the filler mate may comprise graphite.
  • Other possible filler materials may include, for example, spheres of aluminum oxide.
  • the bronze used in the metal bonding agent is selected from the group including copper - tin (Cu/Sn), copper - tin - cobalt (Cu/Sn/Co), copper - tin - r (Cu/Sn/Ni) or copper - tin - silver (Cu/Sn/ Ag). Even more preferred, the bronze i copper - tin - silver bronze. Other bronze alloys can also be considered.
  • the inventive grinding tool can be used for machining hard and/or brittle material This does not exclude the possibility that the grinding tool can be used also for ot materials.
  • the matrix 6 may optionally also comprise at le ⁇ ceramic component in the shape of ceramic particles.
  • the ceramic component may be frit and contain Si0 2 .
  • Ceramic particles for the matrix may be frit in shape of spherical particles having a particle size of 50 ⁇ - 500 ⁇ depending on size of the abrasive particles. For larger abrasive particles, larger ceramic particle; be used.
  • the abrasive particles may be embedded in the ceramic particles while tl ceramic particles are embedded in a hybrid matrix with a metallic bonding agent ⁇ polymeric bonding agent.
  • the ceramic particles may be held stronger by the matr the abrasive particles would be held. The free-cutting properties of the abrasive ri thus improved.
  • the ceramic component does not have such a good resistance to v the metallic bonding agent.

Abstract

The invention relates to a grinding tool 1 for machining brittle materials. The grinding tool 1 has a core 2 and an abrasive rim 4. The abrasive rim 4 comprises abrasive particles 5 embedded in a matrix 6. The matrix 6 comprises a metallic bonding agent and possibly also a polymeric bonding agent. The metallic bonding agent contains silicon nitride in an amount that constitutes 0.02% -5.0 % by volume of the metallic bonding agent. The invention also relates to a method of manufacturing the grinding tool. In the method, abrasive particles are mixed with metal powder and silicon nitride and the mixture is sintered. Polymeric powder may also be added before sintering.

Description

A GRINDING TOOL FOR MACHINING BRITTLE MATERIALS AND A METHOD OF MAKING A GRINDING TOOL
FIELD OF THE INVENTION
The invention relates to a grinding tool, in particular a grinding tool for grinding hard and/or brittle materials such as tungsten carbide. The grinding tool may in particular be a grinding wheel. The invention also relates to a method of making such a grinding tool. BACKGROUND OF THE INVENTION
Grinding tools such as grinding wheels are used for machining of brittle materials. One area where such grinding tools are used is machining of tools that are made of hard metal (tungsten carbide). For example, grinding tools may be used for machining operations in which drills or milling tools are shaped by grinding. If the work piece which is to be shaped is made of a hard material such as tungsten carbide, the abrasive tool must have abrasive particles of a very hard material. In practice, this normally means that the abrasive particles are diamond particles or grains of cubic boron nitride. Diamonds or cubic boron nitride grains for this purpose are commercially available and can be considered as standard components. Diamonds for this purpose may typically have an average or mean particle size of 50μιη (the size of the particles is of course varying) and have a plurality of sharp edges that can cut hard materials such as tungsten carbide.
A known type of grinding tool for this purpose is a grinding wheel with a core which may be made of, for example, a metallic material such as steel or aluminum. The core may also be made of a non-metallic material such as a polymeric material. The core can be shaped as a disc which can be mounted on a tool spindle for rotation about the axis of the disc-shaped metal core. An abrasive rim surrounds the core and is joined to the core. The abrasive rim may comprise abrasive particles embedded in a matrix with one or more bonding agents. The material used in the abrasive rim is normally more expensive than the material of the core. For this reason, the abrasive rim has a smaller extension in the radial direction than the core (i.e. the abrasive rim is normally a smaller part of the grinding wheel since it is more expensive). During grinding, the abrasive rim is gradually worn down until it is consumed and the grinding wheel can no longer be used. Known bonding agents for abrasive rims of grinding wheels include polymeric b agents such as, for example, Bakelite. Alternatively, the bonding agent may be a ceramic bonding agent. It is also known to use metallic bonding agents, in particu bonding agents of bronze that have been made by sintering. In such sintering opei metal powder containing copper and tin is sintered together with abrasive particle as diamond particles or grains of cubic boron nitride. Sometimes, silver can be ad such that the bronze contains copper (Cu), tin (Sn) and silver (Ag). In the past, pr; experience has showed that Cu/Sn/Ag alloys function well as bonding agents for abrasives and that such bonding agents function well during grinding. Although tl precise reason for this is not entirely understood, it is believed by the inventors th improved thermal conductivity caused by the addition of silver may explain why alloys comprising silver function well as bonding agents for abrasives. However, silver is expensive, other bronze alloys may be used in order to reduce the cost an present invention is applicable also to bronze alloys without silver.
Other known bronze compositions for this purpose include copper/tin/cobalt (Cu/ and copper/tin/nickel (Cu/Sn/Ni). It has also been suggested that bronze composit for this purpose may include copper/tin/titanium (Cu/Sn/Ti). Yet another known system includes hybrids of polymeric and metallic bonding a£ in which metallic powder is sintered together with polymeric material such that a is formed in which the polymeric bonding agent and the metallic bonding agent (typically a bronze alloy as described above) are closely intertwined with each otl a microscopic level. In such hybrids, the metal bonding agent and the polymeric bonding agent each forms a network and the respective networks of the bonding a penetrate each other. Such a hybrid matrix that comprises both a metal bonding a\ and a polymeric bonding agent is disclosed in for example US patent No. 606314
In addition to metallic and polymeric bonding agents, such hybrids normally inch one or several fillers. One such filler may be graphite which is used for its lubrica properties.
The abrasive particles used may have different properties. For example, the brittk of diamonds may vary depending on the purpose for which the grinding tool is to used. The properties of different diamonds may be matched to meet the properties different bonding agents (or hybrids of bonding agents). In a good grinding tool, the abrasive particles should be bonded in its matrix in su way that the grinding tool functions as desired. It is desirable that the grinding toe a good resistance to wear such that it can be used over an extended period. Howe1 good wear resistance is not the only desired property and the grinding tool with tt highest resistance to wear is not necessarily the best choice. Other desirable propt include low energy consumption (i.e. that the power required to drive the grinding is not excessively high) and constant or at least predictable performance propertie the grinding effect of the abrasive rim varies too much over time, this causes prob This is especially the case if the performance of the grinding tool varies in a way unpredictable.
The extent of wear of the grinding tool under given circumstances depends to a v< high degree on the properties of the matrix in which the abrasive particles are embedded. Therefore, the composition of the matrix is important.
When a grinding tool is used for machining a work piece, sharp corners and edge: the abrasive particles act on the work piece. Thereby, force is exerted on abrasive particles embedded in the matrix. During the grinding, the abrasive particles are damaged. Gradually, small pieces break loose from the abrasive particles such th abrasive particles are gradually worn down. When the abrasive particles in one ar the abrasive rim have been completely worn down, the work piece meets the mati directly. The matrix as such is less hard than the work piece and it is quickly won down. As a result, fresh abrasive particles come to the surface of the abrasive rim can start to act on the work piece.
However, if the matrix that holds the abrasive particles is too weak, abrasive parti may be torn away from the matrix before they have been worn down. When this happens in part of the surface of the abrasive rim, the work piece will come into c contact with the relatively brittle matrix and wear down the matrix prematurely. this happens, power consumption drops momentarily until so much of the matrix been worn down that fresh abrasive particles come to the surface. As a result, the abrasive rim of the grinding tool is worn out faster than it would otherwise have b the operation of the grinding tool has been programmed in advance, the conseque thereof may be that the grinding operation does not function properly since the gr tool is set to operate based on an assumption of tool diameter that is now incorrec problem becomes more serious if the abrasive rim is worn out in a way that is difi to predict, for example if wear occurs in sudden stens that come in irreeular inten It is also desirable that the required power for the grinding operation can be kept 1 such that the energy consumption during grinding can be minimized. Another desirable property of grinding tools is a high G-ratio. The G-ratio expres; ratio between the volume of the material removed by the grinding tool from a wo: piece and the volume lost by the grinding tool (the wear on the tool). A good grin tool has a high G-ratio. Therefore, it is an object of the present invention to provide a grinding tool that h; good resistance to wear. Further objects of the invention are to provide a tool that worn out in a regular and predictable way, which has a low power requirement an high G-ratio. These objects are achieved by means of the present invention as wil explained in the following.
SUMMARY OF THE INVENTION
The invention relates to a grinding tool. The grinding tool is especially intended a grinding tool for machining hard and/or brittle materials, such as tungsten carbide the inventive grinding tool could also be used for grinding other materials. The gr tool comprises a core and an abrasive rim. The abrasive rim comprises abrasive p embedded in a matrix and the matrix comprises a metallic bonding agent which is sintered bronze alloy. The metallic bonding agent constitutes 50 % - 100 % by vo of the matrix. According to the invention, the metallic bonding agent contains sili nitride in an amount that constitutes 0.02 % - 5.0 % by volume of the metallic bot agent or optionally 0.1 % by volume - 5.0 % by volume of the metallic bonding a
In embodiments of the invention, the matrix may further optionally comprise a polymeric bonding agent that has been sintered together with the metallic bondinj such that the polymeric bonding agent and the metallic bonding agent form a com network.
In embodiments of the invention, the silicon nitride constitutes 0.3 % - 5.0 % by -\ of the metallic bonding agent. For example, it may constitute 0.5 % - 5.0 % by vo of the metallic bonding agent, 1.0 % - 5.0 % by volume of the metallic bonding a or 0.5 % - 3.0 % by volume or 0.5 % - 2.0 % by volume. The silicon nitride may be present in the shape of grains having an average grain which is preferably less than ΙΟμιη but also preferably above Ο. ΐμιη. Such particli be 1250 Tyler mesh particles. The particles may thus include particles up to ΙΟμη though average grain size is smaller.
When a polymeric bonding agent is part of the matrix, the polymeric bonding age comprise polyimide or be made entirely or almost entirely of polyimide.
The matrix may optionally additionally comprise filler materials such as graphite. Graphite has lubricating properties which may be desirable during grinding.
The metallic bonding agent is preferably a bronze alloy that comprises copper, tin silver. The abrasive particles may be, for example, diamond particles or cubic boron nitr particles. For both diamonds and cubic boron nitride, the abrasive particles may h mean particle size in the range of 4μπι - 18 Ιμπι. In many realistic embodiments, abrasive particles may have a size in the range of 46μπι - 91μπι. In embodiments invention, the abrasive particles may have a coating of copper or nickel.
The invention also relates to a method of making the inventive grinding tool. The method comprises sintering abrasive particles together with metallic powder such the sintering results in a matrix in which the abrasive particles are embedded. The matrix will thereby comprise a metallic bonding agent. The metallic powder com] copper and tin such that the metallic bonding agent will be a sintered bronze allo According to the invention, silicon nitride in the form of a powder is added to the metallic powder before sintering and to such an extent that the silicon nitride will constitute 0.02 % - 5.0 % by volume of the metallic bonding agent and preferably - 5.0% by volume of the metallic bonding agent.
In embodiments of the inventive method, the metallic powder may additionally comprise silver.
When reference is made to the relative proportion of silicon nitride in the metal bi agent, it should be understood that this refers to the volume proportion of the pow used in the manufacturing process. In other words, the method of manufacturing i that, in the powder added before sinterine. silicon nitride will constitute 0.02 % - by volume of the metallic bonding agent (the silicon nitride being counted as part metal bonding agent). It is assumed that the silicon carbide particles will retain th relative proportion of total volume also after sintering. Optionally, a polymer is added to the metallic powder before sintering, preferabl} form of polyimide powder, such that also a polymeric bonding agent is formed wl a part of the matrix.
The method may be carried out in such a way that the powder material for the bot agents of the matrix is mixed with the abrasive particles to form a mixture. The m is then compacted in a cold press. The compacted mixture is then cured in a kiln∑ temperature in the range of 380°C - 520°C, preferably 400°C - 500°C, for a perio 120 - 150 minutes. Thereafter, the compacted and cured mixture is placed in a pri subjected to a pressure of 1500 - 2000 kg/cm2. The pressure is then held until the mixture has reached a temperature below 300°C.
Optionally, filler material is added to the mixture of metallic powder and abrasive particles before the sintering operation. The filler material may optionally compri graphite.
The matrix of the inventive grinding tool may advantageously be a matrix which : hybrid, i.e. a matrix having both a metal bonding agent and a polymeric bonding ; Hybrid bonding solutions can combine the best properties of metal bonding agent the best properties of polymeric bonding agents. If re-sharpening by a sharpening needed, a grinding tool with a hybrid matrix can be re-sharpened easier than a pui metal matrix. At the same time, a grinding tool with a hybrid matrix has better resistance to wear than a matrix using only a polymeric bonding agent.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic representation of a grinding tool.
Figure 2 is a schematic cross sectional representation of abrasive particles embedded in the abrasive rim of a grinding tool.
Figure 3 is a schematic cross sectional representation of a grinding tool that z
a work piece.
Figure 4 is a diagram that represents the power consumption for two differen grinding tools. Figure 5 is a schematic cross sectional representation of a first embodiment c inventive grinding tool.
Figure 6 is a schematic cross sectional representation of a second embodimer the inventive grinding tool.
Figure 7 is a diagram that shows wear of a grinding tool as a function of silic nitride content.
Figure 8 is a diagram that shows the G-ration of a grinding tool as a function silicon nitride content. DETAILED DESCRIPTION OF THE INVENTION
With reference to Figure 1, a grinding tool 1 is shown. The grinding tool may in particular be a grinding wheel which is intended for machining hard and/or brittle materials such as tungsten carbide. Such materials may be present in work pieces tools such as for example drills or milling tools and the grinding tool 1 of the pres invention may be a grinding wheel that is used for shaping such tools. The grindii 1 comprises a core 2 and an abrasive rim 4. The core 2 may be made of a less exp material such as steel or some other metal. Alternatively, the core could be made example, a polymeric material. The core could also comprise more than one mate For example, it could be made partially by metal such as steel or aluminum and p be a polymeric material. The core 2 may be provided with a through-hole or cavit such that the grinding tool 1 may be mounted on a spindle (not shown) for rotary movement. With reference to Figure 2, the abrasive rim 4 comprises abrasive pari embedded in a matrix 6. The matrix 6 in turn comprises a metallic bonding agent is a sintered bronze alloy. The metallic bonding agent constitutes 50 % - 100 % b; volume of the matrix 6 and embodiments are thus conceivable in which the entire matrix 6 is made up of the metallic bonding agent. However, the matrix 6 normal! comprises at least some other component. For example, it may comprise filler sue graphite that has lubricating properties. In most embodiments, the matrix 6 would comprise a polymeric bonding agent that may be formed by polyimide.
If the matrix 6 holds the abrasive particles 5 well, the abrasive particles 5 will em small fragments and be worn down gradually. As a result, the wear on the abrasiv 4 will be relatively slow such that the diameter of the grinding tool 1 can be kept substantially constant during a longer period. Moreover, wear on the abrasive rim be kept at an even pace and the power during operation will not vary so much. If the matrix 6 is instead incapable of holding the abrasive particles 5 firmly, it mi happen that abrasive particles come loose well before they have been fragmented, consequence, they will be lost before their entire abrasive potential has been used abrasive tool 1 will be worn out faster and the diameter of the grinding tool (such grinding wheel) will decrease faster. A smaller diameter of the grinding tool 1 ma result in a less accurate machining of the work pieces.
With reference to Figure 3, a grinding tool 1 acts on a work piece 7. The work pie may be, for example, a work piece that shall be shaped to a drill. The grinding toe rotated by means of a power source acting through for example a spindle (not sho Thereby, the abrasive rim 4 of the grinding tool acts on the work piece 7 to cut a \ in the work piece. In Figure 3, the work piece has a core diameter CD which is determined by the action of the grinding tool 1. If the grinding tool 1 is worn dow that its diameter decreases, the core diameter CD will grow unless the wear is compensated (for example by repositioning of the grinding tool 1 in relation to th piece 7). It is therefore very desirable that the wear can be kept low and that the w that does take place does not come in sudden unpredictable leaps.
It can be added that, when the abrasive particles 5 are properly fragmented piece 1 piece, this is good for the free-cutting properties of the grinding tool 1, i.e. the abi the grinding tool to re-sharpen itself. When the abrasive particles 5 become fragm step by step, the wear on the matrix 6 can occur smoothly and the surface of the abrasive rim 4 does not become clogged so easily. If abrasive particles are insteac away suddenly before they have been properly fragmented, this tends to lead to increased clogging of the surface; the surface of the abrasive rim 4 may become c to a greater extent by small particles 5 from the work piece 7. This may necessital temporary removal of the grinding tool 1 from operation such that the grinding to may be re-sharpened. If the abrasive particles 5 are gradually fragmented, the risk such clogging is smaller. When abrasive particles have been completely worn out abrasive particles 5 may come to surface in a smoother process which in itself contributes to re-sharpening of the grinding tool (or rather the abrasive rim 4 of tt grinding tool 1).
When abrasive particles are torn away from the abrasive rim before they have bee completely fragmented, this tends to show itself in the power consumption of the grinding tool; the power suddenly drops and then starts to rise again after a while, abrasive particles are held nronerlv bv the matrix so that thev are allowed to fragr they should, also this can be seen on the power consumption. In such a case, the p tends to remain relatively constant over time (it should be noted, however, that tfr normally always a gradual increase in the power requirement from the first work such that less power is required for the very first work pieces).
It has been suggested in an article by E. D. Kizikov and P. Kebko ("Microadditio, alloys of the system Cu-Sn-Tf Institute of Superhard Materials, Academy of Sck the Ukrainian SSR, Kiev, in translation from Metallovedenie I Termicheskaya Obrabotka Metallov, No. 1, pp 50 - 53, January 1987) that an alloy of Cu/Sn/Ti v is to be used as binder for diamond-abrasive tools be reinforced with 0.01% silicc nitride (S13N4). According to the authors of that article, this addition resulted in improved yield strength.
The inventors of the present invention have considered what steps can be taken tc improve the ability of the matrix to hold the abrasive particles. Without wishing fc bound by theory, the inventors believe that one reason that metal bonding agents 1 the abrasive particles embedded therein may be that dislocations inside the metal bonding agent weaken the metallic bonding agent. Assuming this theory to be coi the inventors first speculated that it should be possible to improve the matrix by reinforcing it with particles blocking dislocations in the metal bonding agent.
Consequently, the inventors tried different additions to the metal powder that was for sintering the metal bonding agent. One additive that was tried was aluminum < which was added to an extent corresponding to 1.0 % by volume of the metal bon agent. This resulted in a certain improvement but the improvement was not as goc the inventors had hoped. The inventors also tried addition of 0.01 % by volume oi silicon nitride. The improvement of that addition was even less than the improver achieved by the aluminum oxide.
The inventors then investigated whether increased amounts of silicon nitride wou produce better results. This was confirmed in testes carried out by the inventors. silicon nitride was added in quantities significantly larger than 0.01 % by volume metal bonding agent, it was discovered that a very substantial improvement was obtained. For example, the inventors tested a composition in which the metal bonding agen contained 1.0 % by volume of silicon nitride (S13N4). A grinding tool with this composition was then comnared to a standard erindine tool usine a hvbrid matrix which did not contain silicon nitride (Si3N4). The grinding tools were both grindii wheels in which the abrasive rim 4 was shaped as a ring surrounding the core 2. 1 comparable conditions, the diameter of the standard tool was worn down by 136μ while the diameter of the grinding tool with the experimental composition was w( down by only 58μιη. The G-ratio for the tool with 1.0 % silicon nitride was 2335. comparison, a tool using 0.01 % by volume of silicon nitride was worn down 94μ while a tool using 1.0 % by volume aluminum oxide was worn down 84μιη.
A test was made with a composition where silicon nitride constituted 5 % by volu the metal bonding agent. The resistance to wear was still good but not quite as go for the grinding tool with 1.0% by volume silicon nitride. Moreover, the tool with silicon nitride had higher power consumption. The G-ratio was good but not quite good as for the tools with 1.0% and 0.1 % by volume. The inventors have also tested a grinding wheel which had a shape and a composi similar to the other tools tested but in which the silicon nitride constituted 0.1 % 1 volume of the metal bonding agent. It was found that, under the same test conditi< the other tools that were tested, the wear of the tool with 0.1 % by volume silicon was 62μιη and the G-ration was 2084. While this was inferior to the results obtair 1 % by volume, it was still a very substantial improvement compared to the stand grinding tool.
The inventors have also tested a grinding wheel which had a silicon nitride conter 0.02 % by volume of the metal bonding agent but which was otherwise similar to other grinding wheels tested. Under similar test conditions, the grinding wheel wi % by volume of silicon nitride has a wear (diameter reduction) of 58μιη and a G-i 2283. The results were thus slightly better than the results obtained at a ratio of 0. by volume. The results lead to the conclusion that significantly better results are obtained in tl range of 0.02 % - 5.0 % by volume silicon nitride (S13N4). In this range, both G-n and resistance to wear has been found to be significantly better than at 0% or 0.01
Tests of resistance to wear and test of G-ratio have been carried out at 0 % by vol 0.01 % by volume, 0.02 % by volume, 1.0 % by volume and 5.0 % by volume sili nitride. The tools that were tested were grinding wheels of substantially the kind shown ii Figure 5, i.e. grinding tools with an abrasive rim 4 that surrounds a core 2 and wh grinding tool 1 rotates about the axis A during operation. Resistance to wear as a function of silicon nitride content can be seen in Figure 7. The resistance to wear expressed in Figure 7 as diameter reduction. As can be seen in Figure 7, resistanc wear increased significantly when the content of silicon nitride was increased froi % to 0.02 %. The wear resistance continued to be high up to a silicon nitride cont 5.0 % by volume of the metallic bonding agent. However, at 5.0 % by volume sili nitride, the resistance to wear was somewhat lower compared to the resistance ob; at a content of 0.02 % - 1.0 %. The inventors have therefore concluded that the be wear resistance is obtained in the range of 0.02 % - 5.0 % by volume.
The G-ratio as a function of silicon nitride content can be seen in Figure 8. As cai seen in the figure, the best values are obtained at a silicon nitride content in the ra 0.02 % - 5.0%. From Figure 8, it can also be derived that the G-ratio is sinking to the right in the figure even though the G-ratio at 5.0% by volume is still good.
Therefore, the inventors have concluded that the metallic bonding agent may conl silicon nitride in an amount that constitutes 0.02 % - 5.0 % by volume of the mete bonding agent. Since power consumption was higher at 5.0 % by volume, the inv have concluded that values lower than 5.0% will have good resistance to wear bui power consumption compared to tools with a silicon nitride content of 5% by voli Therefore, a preferred range may be 0.02 % by volume to 3.0% by volume, 0.5 % % by volume, 0.5 % - 2.0 % by volume or 1.0 % - 2.0 % by volume of the metalli bonding agent.
At 0.1 % by volume, power consumption was generally lower than at 0.02 % by volume. At a silicon nitride of 5.0 % by volume, power consumption was higher 1 a content of 0.02 % but the power consumption at 5.0 % by volume was more eve power consumption was more predictable than at 0.02 % by volume.
The silicon nitride particles should preferably have a size up to ΙΟμπι (1250 Tylei mesh). For sieved particles, this will normally mean that average grain size is less ΙΟμπι. The average particle size (D50) of the silicon nitride particles may then be 2μπι - 3μπι (depending on how average particle size is measured). The specific su area of the silicon nitride particles may advantageously be in the range of 5 m2/g - m2/g. If the particles used are too small, this mav result in cloeeine and difficultie during manufacturing. Moreover, for giving optimized strength to the metal bond agent, it is believed by the inventors that particles up to ΙΟμιη should preferably b included. Normally, the matrix 6 should further comprise a polymeric bonding agent that h< sintered together with the metallic bonding agent such that the polymeric bonding and the metallic bonding agent form a connected network (even though such a polymeric bonding agent is optional). The use of a polymeric agent makes it poss fine tune the properties of the matrix and adapt it to different kinds of abrasive pa The polymeric bonding agent may suitably be polyimide or comprise polyimide. ' reason for this is that polyimide is heat resistant and can withstand the high temperatures during sintering. If a polymeric bonding agent is used, the polymerii bonding agent may be present in an amount of up to 50% by volume of the matri? the amount of polymeric bonding agent is in the range of 0% - 50% by volume of matrix). For example, the polymeric bonding agent may represent 10 % - 40 % oi 30% by volume of the matrix.
Possibly, the polymeric bonding agent could be formed by some other polymeric material. For example, it could be formed by polyamide-imide which is also capa withstanding high temperatures. However, polyimide is preferred since it has bett grinding properties than polyamide-imide.
The metallic bonding agent is a preferably a bronze alloy that comprises copper, t silver. Silver improves the desirable properties of the metal bonding agent.
The abrasive particles 5 may be either diamond particles or cubic boron nitride p∑ Diamonds are harder and have better abrasive properties but cubic boron nitride i: temperature resistant. Moreover, diamonds may react chemically with certain ma1 The abrasive particles 5 may be are diamond particles or particles of cubic boron nitride. The particles may be in the range of 4μπι - 18 Ιμτη even though particles c this range may be considered depending on the requirements in each specific case many realistic embodiments, the abrasive particles 5 may have a mean particle si the range of 46μπι - 91 μπι which is a range that is suitable for many grinding operations. The abrasive particles 5 may optionally have a coating of copper or nickel. A coa copper or nickel can improve the bond between the abrasive particles 5 and the m 6. However, the abrasive properties of the particles 5 will be somewhat reduced ii particles have such a coating.
The relative proportion of abrasive particles 5 in relation to the bonding agents an fillers in the matrix 6 may vary depending on the requirements in each case. In mi realistic embodiments, the amount of abrasive particles may represent a 10 % - 5( the total volume of the abrasive rim (i.e. the total volume of the abrasive particles the matrix). If the relative proportion of abrasive particles is higher than 50 %, tt substantial danger that the matrix will no longer be able to hold the abrasive partii the relative proportion of abrasive particles is less than 10 %, the grinding effect r become too small. The relative proportion of abrasive particles may preferably be range of 15 % - 30 % and a suitable value may be 25 %.
Preferably, the silicon nitride is present in the shape of grains having an average £ size which is equal to or less than ΙΟμπι but above 0.1 μπι. For example, they may a mean size in the range of Ι μτη - ΙΟμπι or 2μπι - 9μπι . It is believed by the inver that silicon nitride particles smaller than 0.1 μπι may result in clogging of the silic nitride particles which reduces their reinforcing effect.
The silicon nitride particles may have three different crystallographic structures designated as α, β and γ phases (also known as trigonal phase, hexagonal phase ai cubic phase). The a and β phases are the most common. The γ phase can only be synthesized under high pressure and high temperature. Any of these phases can b< Preferably, the phase used is the a phase. The silicon nitride particles added may ; a mixture of particles of different phases.
With reference to Figure 4, a grinding tool according to the invention is comparec a standard grinding tool. The vertical axis represents power consumption while th horizontal axis represents number of work pieces upon which the respective grind tool has acted. In Figure 4, B5 represents a grinding tool according to the inventic while EZ represents a standard grinding tool. As can be seen in Figure 4, the tool represented as B5 has a power consumption that first rises steeply and thereafter remains substantially constant. The conventional tool as represented by EZ has a consumption that rises steeply and then suddenly drops before it rises again. This indicates that the abrasive narticles of the B5 tool are slowlv fragmented while Έ/ represents a grinding tool where the abrasive particles are suddenly torn away. Tr on the tool will therefore be faster.
It can be added that B5 represents a tool with both a metal bonding agent and a polymeric bonding agent. The metal bonding agent is a bronze that has copper, til silver. It has been sintered using a metal powder that contains 45 % by volume co 45 % by volume tin and 10 % by volume silver. In the tool according to B5, the polymeric bonding agent constitutes 1.0 % by volume of the total amount of bone agent.
The grinding tool of Figure 1 may have a cross section as shown in Figure 5. In si embodiment, the abrasive rim 4 is placed radially outside the core 2 such that the completely surrounds the core 2. The tests explained with reference to Figure 4, 1 7 and Figure 8 have been carried out on such a grinding tool. However, the invenl not limited to such an embodiment. With reference to Figure 6, it should be undei that the core 2 may extend at least as much in the radial direction as the abrasive i In Figure 6, the grinding tool has an abrasive rim 4 that does not extend beyond tl 2 in the radial direction. Instead, the abrasive rim 4 has an extension in the axial direction that is different from that of the core 2 (the axial direction being the axis rotation A of the grinding tool 1 when it is driven by a spindle, see Figure 5 and F 6). It should also be understood that the grinding tool 1 is not necessarily designei rotation. Instead, it could act on work pieces in a reciprocating movement. In the context of the claims, the term "core" should thus be understood broadly as any k carrier body for the abrasive rim. Likewise, the term "rim" should also be underst broadly as any kind of layer secured to the core 2 such that abrasive particles can a work piece.
The invention further comprises a method of making the inventive grinding tool, method comprises sintering abrasive particles together with metallic powder that comprises copper and tin such that the sintering results in a matrix in which the al particles 5 are embedded. The matrix comprises a metallic bonding agent which i; sintered bronze alloy. According to the invention, silicon nitride in the form of a j is added to the metallic powder before sintering to such an extent that the silicon i will constitute 0.1% - 5.0% by volume of the metallic bonding agent.
The metal powder used is preferably metal powder with particles that are smaller 44μπι but they should nreferablv be lareer than the silicon nitride narticles. Prefer they should be at least twice as large. An average size in the range of 15μιη - 44μ be suitable.
The metallic powder may optionally also comprise silver.
The metal powder may come in the shape of pre-alloyed particles or as particles c copper, pure tin, pure silver etc.
A polymer may be added to the metallic powder before sintering, preferably in th of polyimide powder, such that also a polymeric bonding agent is formed which i part of the matrix 6.
The sintering method may be carried out such that the powder material for the boi agents of the matrix 6 is mixed with the abrasive particles 5. The mixture is comp in a cold press. Thereafter the compacted is mixture is cured in a kiln at a tempen the range of 380°C - 520°C, preferably 400°C - 500°C or 440°C - 460°C, for a pe 120 - 150 minutes. The time required depends on size. In a larger press form, mo is required. Thereafter (preferably immediately thereafter) the compacted and cur mixture is placed in a press and subjected to a pressure of 1500 - 2000 kg/cm2 Tt pressure is then maintained until the mixture has reached a temperature below 30<
For example, the inventors have made grinding tools according to this method in process where the temperature in the kiln was 450°C. The abrasive rim 4 may also be manufactured by means of spark plasma sintering (SPS). By this technique, the abrasive rim 4 may be manufactured very fast.
The rim with the matrix containing abrasive particles may be sintered separately∑ subsequently fastened (e.g. glued) onto the core 2. Alternatively, the abrasive rim be sintered directly onto the core 2 such that it is bonded to the core as it is forme Before sintering, the core 2 may be electrolytically plated with copper on at least surface of the core which will meet the abrasive rim 4. The abrasive rim 4 can the sintered onto the copper-plated surface such that a seam is formed. Filler material may optionally be added to the mixture of metallic powder and abi particles 5 before the sintering operation. As previously explained, the filler mate: may comprise graphite. Other possible filler materials may include, for example, spheres of aluminum oxide.
Preferably, the bronze used in the metal bonding agent is selected from the group including copper - tin (Cu/Sn), copper - tin - cobalt (Cu/Sn/Co), copper - tin - r (Cu/Sn/Ni) or copper - tin - silver (Cu/Sn/ Ag). Even more preferred, the bronze i copper - tin - silver bronze. Other bronze alloys can also be considered.
The inventive grinding tool can be used for machining hard and/or brittle material This does not exclude the possibility that the grinding tool can be used also for ot materials.
In embodiments of the invention, the matrix 6 may optionally also comprise at le∑ ceramic component in the shape of ceramic particles. The ceramic component ma for example, frit and contain Si02. Ceramic particles for the matrix may be frit in shape of spherical particles having a particle size of 50μπι - 500μπι depending on size of the abrasive particles. For larger abrasive particles, larger ceramic particle; be used. The abrasive particles may be embedded in the ceramic particles while tl ceramic particles are embedded in a hybrid matrix with a metallic bonding agent < polymeric bonding agent. The ceramic particles may be held stronger by the matr the abrasive particles would be held. The free-cutting properties of the abrasive ri thus improved. The ceramic component does not have such a good resistance to v the metallic bonding agent. By combining ceramics, metal and polymeric bonding agents, it is possible to combine the best properties of these bonding agents.

Claims

1. A grinding tool (1) for machining hard and/or brittle materials whicl grinding tool (1) comprises a core (2) and an abrasive rim (4), the abrasive rim (4 comprising abrasive particles (5) embedded in a matrix (6), the matrix (6) compri metallic bonding agent which is a sintered bronze alloy, the metallic bonding agei constituting 50 % - 100 % by volume of the matrix, the metallic bonding agent containing silicon nitride in an amount that constitutes 0.02 % - 5.0 % by volume metallic bonding agent characterized in that the silicon nitride is present in the sh< grains having an average grain size which is less than ΙΟμιη and above 0. Ι μπι.
2. A grinding tool (1) according to claim 1, wherein the matrix (6) furt comprises a polymeric bonding agent that has been sintered together with the met bonding agent such that the polymeric bonding agent and the metallic bonding ag form a connected network.
3. A grinding tool (1) according to claim 1 or claim 2, wherein the sili< nitride constitutes 0.3 % - 5.0 % by volume of the metallic bonding agent, prefera
0.5 % - 3 % by volume and even more preferred 0.5 % - 2 % by volume.
4. A grinding tool according to claim 2, wherein the polymeric bondin agent comprises polyimide.
5. A grinding tool according to claim 1 or claim 2, wherein the matrix additionally comprises filler materials such as graphite.
6. A grinding tool according to any of claims 1 - 5, wherein the metall bonding agent is a bronze alloy that comprises copper, tin and silver.
7. A grinding tool according to any of claims 1 - 6, wherein the abrasi particles (5) are diamond particles or cubic boron nitride particles.
8. A grinding tool according to claim 7, wherein the abrasive particles have a mean particle size in the range of 4μπι - 181 μπι and preferably in the rang( 46μπι - 91 μπι.
9. A grinding tool according to claim 8, wherein the abrasive particles have a coating of copper or nickel.
10. A method of making a grinding tool (1) which method comprises sii abrasive particles together with metallic powder that comprises copper and tin su< the sintering results in a matrix (6) in which the abrasive narticles (6) are embedd matrix comprising a metallic bonding agent which is a sintered bronze alloy, characterized in that silicon nitride in the form of a powder is added to the metalli powder before sintering and to such an extent that the silicon nitride will constitui % - 5.0% by volume of the metallic bonding agent and wherein the silicon nitride is added is in the shape of grains having an average grain size which is less than 1 and above 0.1 μιη.
11. A method according to claim 10, wherein the metallic powder addit comprises silver.
12. A method according to claim 10 or claim 11, wherein a polymer is to the metallic powder before sintering, preferably in the form of polyimide powd such that also a polymeric bonding agent is formed which is a part of the matrix (
13. A method according to any of claims 10 - 12, wherein the method comprises; mixing the powder material for the bonding agents of the matrix (6) w abrasive particles (5); compacting the mixture in a cold press; curing the compact mixture in a kiln at a temperature in the range of 380°C - 520°C, preferably 400°( 500°C, for a period of 120 - 150 minutes; thereafter placing the compacted and ci mixture in a press and subjecting it to a pressure of 1500 - 2000 kg/cm2; and hole the pressure until the mixture has reached a temperature below 300°C.
14. A method according to any of claims 10 - 13, wherein filler materia added to the mixture of metallic powder and abrasive particles (5) before the sinti operation and wherein the filler material comprises graphite.
EP12817725.0A 2011-07-22 2012-07-18 A grinding tool for machining brittle materials and a method of making a grinding tool Active EP2734334B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE1150720A SE537723C2 (en) 2011-07-22 2011-07-22 A grinding tool for machining brittle materials and a process for making a grinding tool
PCT/SE2012/050842 WO2013015737A1 (en) 2011-07-22 2012-07-18 A grinding tool for machining brittle materials and a method of making a grinding tool

Publications (3)

Publication Number Publication Date
EP2734334A1 true EP2734334A1 (en) 2014-05-28
EP2734334A4 EP2734334A4 (en) 2015-11-11
EP2734334B1 EP2734334B1 (en) 2022-11-02

Family

ID=47601365

Family Applications (1)

Application Number Title Priority Date Filing Date
EP12817725.0A Active EP2734334B1 (en) 2011-07-22 2012-07-18 A grinding tool for machining brittle materials and a method of making a grinding tool

Country Status (15)

Country Link
US (1) US20140227952A1 (en)
EP (1) EP2734334B1 (en)
JP (1) JP5982725B2 (en)
KR (1) KR101861890B1 (en)
CN (1) CN103781596B (en)
AU (1) AU2012287547B2 (en)
BR (1) BR112014001447A2 (en)
CA (1) CA2842534A1 (en)
IL (1) IL230524A (en)
MX (1) MX358578B (en)
MY (1) MY169695A (en)
RU (1) RU2594923C2 (en)
SE (1) SE537723C2 (en)
WO (1) WO2013015737A1 (en)
ZA (1) ZA201400915B (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016208646A1 (en) * 2015-06-22 2016-12-29 京セラ株式会社 Cutter
JP6687231B2 (en) * 2015-07-15 2020-04-22 三井研削砥石株式会社 Polishing tool, method for manufacturing the same, and method for manufacturing an abrasive
CN109571291A (en) * 2018-12-20 2019-04-05 江苏友美工具有限公司 Multifunctional mill cuts diamond-impregnated wheel and its preparation process
WO2021161332A1 (en) * 2020-02-11 2021-08-19 INDIAN INSTITUTE OF TECHNOLOGY MADRAS (IIT Madras) System and method for developing uni-layer brazed grinding wheels by placing grit in a pre-defined array

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SU1021586A1 (en) * 1982-01-27 1983-06-07 Всесоюзный научно-исследовательский конструкторско-технологический институт природных алмазов и инструмента Metallic binding for making diamond tool
JPS61100374A (en) * 1984-10-23 1986-05-19 Toyota Banmotsupusu Kk Grinding wheel
JPS61111885A (en) * 1984-11-06 1986-05-29 Showa Denko Kk Molding for grinding
RU2101164C1 (en) * 1995-11-22 1998-01-10 Институт сверхтвердых материалов им.В.Н.Бакуля НАН Украины Abrasive tool binder
AT403671B (en) * 1996-02-14 1998-04-27 Swarovski Tyrolit Schleif GRINDING TOOL WITH A METAL RESIN BINDING AGENT AND METHOD FOR THE PRODUCTION THEREOF
JP3052896B2 (en) * 1997-06-13 2000-06-19 日本電気株式会社 Dress jig on polishing cloth surface and method of manufacturing the same
US6066189A (en) * 1998-12-17 2000-05-23 Norton Company Abrasive article bonded using a hybrid bond
US6200208B1 (en) * 1999-01-07 2001-03-13 Norton Company Superabrasive wheel with active bond
JP2002001668A (en) * 2000-06-19 2002-01-08 Mitsubishi Materials Corp Metal bonded grinding wheel
JP2003094341A (en) * 2001-09-27 2003-04-03 Allied Material Corp Metal bond super abrasive grain grinding wheel
US20050129975A1 (en) * 2002-04-11 2005-06-16 Eiji Ihara Metal-coated abrasives, grinding wheel using metal-coated abrasives and method of producing metal-coated abrasives
JP2007536100A (en) * 2004-05-03 2007-12-13 スリーエム イノベイティブ プロパティズ カンパニー Micro-finish backup shoe and method
CN1788931A (en) * 2005-12-23 2006-06-21 湖南大学 Highly effective deep-grinding process for engineering ceramic material
JP5338107B2 (en) * 2008-03-28 2013-11-13 東レ株式会社 Grinding stone and manufacturing method thereof

Also Published As

Publication number Publication date
CA2842534A1 (en) 2013-01-31
JP5982725B2 (en) 2016-08-31
AU2012287547A1 (en) 2014-03-06
NZ620302A (en) 2015-12-24
EP2734334A4 (en) 2015-11-11
RU2594923C2 (en) 2016-08-20
MY169695A (en) 2019-05-13
KR20140061415A (en) 2014-05-21
US20140227952A1 (en) 2014-08-14
EP2734334B1 (en) 2022-11-02
IL230524A (en) 2017-10-31
SE1150720A1 (en) 2013-01-23
KR101861890B1 (en) 2018-05-28
RU2014106604A (en) 2015-09-10
IL230524A0 (en) 2014-03-31
MX358578B (en) 2018-08-27
WO2013015737A1 (en) 2013-01-31
CN103781596A (en) 2014-05-07
SE537723C2 (en) 2015-10-06
JP2014522740A (en) 2014-09-08
WO2013015737A9 (en) 2013-04-04
ZA201400915B (en) 2014-11-26
MX2014000837A (en) 2014-07-09
BR112014001447A2 (en) 2017-02-21
AU2012287547B2 (en) 2017-02-02
CN103781596B (en) 2016-10-19

Similar Documents

Publication Publication Date Title
KR101269498B1 (en) Abrasive slicing tool for electronics industry
US8382868B2 (en) Cubic boron nitride compact
SK9552001A3 (en) Superabrasive wheel with active bond
JP4443870B2 (en) Super abrasive wheel and manufacturing method thereof
WO2013015737A1 (en) A grinding tool for machining brittle materials and a method of making a grinding tool
CN108119065B (en) Diamond-impregnated bit cutting tooth and manufacturing method thereof
JP2002001668A (en) Metal bonded grinding wheel
KR100407227B1 (en) Composite bond wheel and wheel having resin bonding phase
US20050226691A1 (en) Sintered body with high hardness for cutting cast iron and the method for producing same
JP3791254B2 (en) Compound bond wheel
CN110408828B (en) Artificial diamond drill bit material, drill bit and production process thereof
CN104175237A (en) Diamond grinding wheel adopting rare-earth modified tungsten-based bond and manufacturing method thereof
JP5230474B2 (en) Metal bond wheel
JPS6158432B2 (en)
JPS6331538B2 (en)
JP2003094341A (en) Metal bond super abrasive grain grinding wheel
NZ620302B2 (en) A grinding tool for machining brittle materials and a method of making a grinding tool
JP4496984B2 (en) Resin bond grinding wheel
CN115959658A (en) Polycrystalline diamond, polycrystalline diamond compact and preparation method thereof
JP2020147462A (en) Diamond-based conductive hard sintered material and manufacturing method thereof
JPS58213676A (en) Diamond sintered body for tool and manufacture
JPH03277473A (en) Solid grinding wheel
CN104148641A (en) Diamond angle-grinding wheel made of rare-earth modified tungsten-base binding agent and manufacturing method of diamond angle-grinding wheel
JPH07243060A (en) Porous resin bond wheel
JPH0116894B2 (en)

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20140120

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

RIN1 Information on inventor provided before grant (corrected)

Inventor name: THOLIN, MICHAEL

Inventor name: JOHANSSON, IDA

Inventor name: WESTBERG, FREDRIK

Inventor name: BERGH, STEFAN

DAX Request for extension of the european patent (deleted)
RA4 Supplementary search report drawn up and despatched (corrected)

Effective date: 20151014

RIC1 Information provided on ipc code assigned before grant

Ipc: B22F 3/16 20060101ALI20151008BHEP

Ipc: B24D 3/06 20060101ALI20151008BHEP

Ipc: B24D 3/34 20060101AFI20151008BHEP

Ipc: B24D 3/28 20060101ALI20151008BHEP

Ipc: B22F 7/06 20060101ALI20151008BHEP

Ipc: B24D 99/00 20100101ALI20151008BHEP

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: 3M INNOVATIVE PROPERTIES COMPANY

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

17Q First examination report despatched

Effective date: 20181128

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: GRANT OF PATENT IS INTENDED

RIC1 Information provided on ipc code assigned before grant

Ipc: B22F 1/17 20220101ALN20220429BHEP

Ipc: C22C 32/00 20060101ALI20220429BHEP

Ipc: C22C 26/00 20060101ALI20220429BHEP

Ipc: B24D 18/00 20060101ALI20220429BHEP

Ipc: B24D 7/06 20060101ALI20220429BHEP

Ipc: B24D 5/06 20060101ALI20220429BHEP

Ipc: B24D 5/02 20060101ALI20220429BHEP

Ipc: B24D 3/08 20060101ALI20220429BHEP

Ipc: B22F 3/16 20060101ALI20220429BHEP

Ipc: B22F 7/06 20060101ALI20220429BHEP

Ipc: B24D 3/06 20060101ALI20220429BHEP

Ipc: B24D 3/28 20060101ALI20220429BHEP

Ipc: B24D 99/00 20100101ALI20220429BHEP

Ipc: B24D 3/34 20060101AFI20220429BHEP

INTG Intention to grant announced

Effective date: 20220530

RIN1 Information on inventor provided before grant (corrected)

Inventor name: JOHANSSON, IDA

Inventor name: BERGH, STEFAN

Inventor name: WESTBERG, FREDRIK

Inventor name: THOLIN, MICHAEL

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE PATENT HAS BEEN GRANTED

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

Ref country code: AT

Ref legal event code: REF

Ref document number: 1528420

Country of ref document: AT

Kind code of ref document: T

Effective date: 20221115

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 602012078955

Country of ref document: DE

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: LT

Ref legal event code: MG9D

REG Reference to a national code

Ref country code: NL

Ref legal event code: MP

Effective date: 20221102

REG Reference to a national code

Ref country code: AT

Ref legal event code: MK05

Ref document number: 1528420

Country of ref document: AT

Kind code of ref document: T

Effective date: 20221102

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221102

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230302

Ref country code: NO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230202

Ref country code: LT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221102

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221102

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221102

Ref country code: AT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221102

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: RS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221102

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221102

Ref country code: LV

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221102

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230302

Ref country code: HR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221102

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20230203

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221102

P01 Opt-out of the competence of the unified patent court (upc) registered

Effective date: 20230530

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SM

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221102

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221102

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221102

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221102

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221102

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20230621

Year of fee payment: 12

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 602012078955

Country of ref document: DE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221102

Ref country code: AL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221102

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20230803

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221102

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20230620

Year of fee payment: 12

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221102

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20221102

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20230718

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20230718

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20230718