CA1188103A - Cbn grinding wheel - Google Patents
Cbn grinding wheelInfo
- Publication number
- CA1188103A CA1188103A CA000396042A CA396042A CA1188103A CA 1188103 A CA1188103 A CA 1188103A CA 000396042 A CA000396042 A CA 000396042A CA 396042 A CA396042 A CA 396042A CA 1188103 A CA1188103 A CA 1188103A
- Authority
- CA
- Canada
- Prior art keywords
- wheels
- grinding wheel
- abrasive
- filler
- 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.)
- Expired
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
- B24D3/34—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
- B24D3/344—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 the bonding agent being organic
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Polishing Bodies And Polishing Tools (AREA)
Abstract
ABSTRACT
A CBN grinding wheel is bonded by a resinous matrix including active fillers selected from the group consisting of (1) iron sulfide and an alkali sulfate, (2) potassium aluminum fluoride, and (3) cryolite.
A CBN grinding wheel is bonded by a resinous matrix including active fillers selected from the group consisting of (1) iron sulfide and an alkali sulfate, (2) potassium aluminum fluoride, and (3) cryolite.
Description
C~N _~I nING WiiF.F.L Docket RD-1637 FIELD OF THE INVENTION
This invention relates to orqanic bonded grinding wheels containing cubic boron nitride abrasive and active fillers.
5 BACKGROUND OF THE INVENTION:
~ o-calle~ active fillers such as metal sulfide and haloqen salts such as cryolite which have reactivity toward the material being around have been employed in conventional aluminum oxide abrasive containing orqanic bonded grinding 10 wheels for manv years.
Such qrindinq aid ~illers have not been used in qrindinq wheels containing diamond qrits as the abrasive, because the i~portant use of diamond wheels is in qrinding carbides, qlass and ceramics, particularly ~for resin bonded 15 wheels) in qrinding hard carbides. Grinding aids suitable for qrindinq steel, for example, are of no apparent advantage in carbide qrindinq.
The development of diamond grindinq wheels began in the 1930's, and, until the late 1960's, diamond was the sole 20 "super" abrasive, much harder than the conventional aluminum oxide and silicon carbide abrasives. Concurrent with the development of synthetic diamond bv the hiqh pressure-high tem~erature method tau~ht in General Electric patents issued in the 1960's, the hiqh density cubic form of boron nitride 25 (CBN) having a hardness similar to diamond was discovered, by a~piyin~ hiqh pressur~ to hexagonal ~oron ni~ride at hiqh temperature and in the presence of a catalyst, as disclosed in U.S. Patent 2,947,617.
,~
~ hile not superior to diamond in the grinding of carbides (e.q. cementecl tunqsten carbide) cubic boron nitride (CsN) has been Eound to be superior to diamond when ferrous metals, particularly tool steels are beinq ground. Thus C~N
5 wheels can be superior to diamond wheels in the grinding of tools which combine hard carbides and steels.
Althouqh C~N wheels have been made and tested by others, containinq specific qrinding aids, so far as is known, no commercial use has been made of grindin~ aid 10 fillers in resin bonded C~N wheels.
British Patent 834,351, published in 1960 teaches the use of metal sulfides together with alkali-metal salts such as sulfates as fillers in conventional abrasive wheels for qrindinq alloy steels. While the pat~nt refers to 15 abrasives generally, and lists diamond, such fillers, so far as is known, have never been commercially employed in diamond wheels or in CBN wheels.
Gerrnan Patent P2230701, to Winter h Sohn discloses employinq zinc sulfide with cryolite as a ~rinding aid in 20 stick form to be applied to the workpiece. No suq~estion of incorporatinq the qrindinq aids in the wheel bond appears in the patent.
_MMARY OF THE INVENTION
The present invention is the inclusion in CBN
25 orqanic resin bonded wheels of an iron sulfide filler together with sodium or potassium sulfate. Somewhat inferior to the iron sulfide/alkali sulfate filler are cryolite, or potassium aluminum tetrafluoride, or hexafluoride, in the amount of 8 to 50% bv volume of the qrinding section of the 30 toolO Obviously, combinations of these fillers can be employed. Such wheels, in dry qrinding of tool steels, or qrinding of tool steels in combination with cemented carbides~ show equivalent or better results than the best prior art wheels usinq hond compositions containing silver 35 and drv film lubricants. Elimination of the need for silver is a ma~or economic henefit. These wheels also are advantaqeous in providing qreater freeness of cut and thus more rapid cut of the workpiece.
()3 DE'~\ILF.D DE~ CRIP'rION OF THE INVF.NTION
Wheels according to the present invention may be prepared as followsO
Wheel Pre~aration An intimate mixture of fillers and the csN abrasive is prepared. Fillers are those active materials included as the suh~ect of the application as well as other inert substances. The mixture is then coated with a liquid pickup aqent. A finely divided powdered resin is then mixed with 10 the liquid coated abrasive/filler mixture so as to coat the surfaces of the abrasive and filler particles evenly with resin. In the usual practice, phenolic novolak resin with hexamethylene tetramine crosslinking aqent is chosen as the resin and furfural as the liquid pickup agent.
A typical formulation which illustrates the invention is:
InqredientPercent bv Volume FeS2 11 .SiC 8 Furfural 2 Resin 38 CaO 2 This mixture is then distributed evenly in a groove molded or machined around the circumference of a core. The core is composed of finely divided aluminum powder and resin which has previously been compressed either cold or hot. The wheel, which now consists of the core and circumferentially 30 located abrasive section, is hot pressed to melt and fuse the resin bondinq both the abrasive section and the core.
Pressures to 50 tsi and temperatures from 140 to 200c are applied to the wheel during a period of one-~uarter to one hour to form the wheei Subsequent to this operation the 35 wheel may be heated to a temDerature higher than the molding temperature at at~ospheric pressure to improve grinding characteristics. Finally, the ~heel is machined to prepare a product to standard and fixed dimensional specifications.
~8~
f)ther thermosetti.llg resins or e~uival.ents can be e,lPloyed. The wheels may be straight cyli~drical wheels (lAl shape), or may be cup wheels as in the example above, or mav be any other conventional shape.
S The active filler should be present in a total amount of ~rom 8% to 50% by volume of the qrinding section of the wheel. The ratio of FeS2 to alkali sulfate may be from 4/1 to 1/4 by volume, but is preferably from 40/60 to ~0/40 by volume. Sodium sulfate may replace all or part of the 10 ~254'
This invention relates to orqanic bonded grinding wheels containing cubic boron nitride abrasive and active fillers.
5 BACKGROUND OF THE INVENTION:
~ o-calle~ active fillers such as metal sulfide and haloqen salts such as cryolite which have reactivity toward the material being around have been employed in conventional aluminum oxide abrasive containing orqanic bonded grinding 10 wheels for manv years.
Such qrindinq aid ~illers have not been used in qrindinq wheels containing diamond qrits as the abrasive, because the i~portant use of diamond wheels is in qrinding carbides, qlass and ceramics, particularly ~for resin bonded 15 wheels) in qrinding hard carbides. Grinding aids suitable for qrindinq steel, for example, are of no apparent advantage in carbide qrindinq.
The development of diamond grindinq wheels began in the 1930's, and, until the late 1960's, diamond was the sole 20 "super" abrasive, much harder than the conventional aluminum oxide and silicon carbide abrasives. Concurrent with the development of synthetic diamond bv the hiqh pressure-high tem~erature method tau~ht in General Electric patents issued in the 1960's, the hiqh density cubic form of boron nitride 25 (CBN) having a hardness similar to diamond was discovered, by a~piyin~ hiqh pressur~ to hexagonal ~oron ni~ride at hiqh temperature and in the presence of a catalyst, as disclosed in U.S. Patent 2,947,617.
,~
~ hile not superior to diamond in the grinding of carbides (e.q. cementecl tunqsten carbide) cubic boron nitride (CsN) has been Eound to be superior to diamond when ferrous metals, particularly tool steels are beinq ground. Thus C~N
5 wheels can be superior to diamond wheels in the grinding of tools which combine hard carbides and steels.
Althouqh C~N wheels have been made and tested by others, containinq specific qrinding aids, so far as is known, no commercial use has been made of grindin~ aid 10 fillers in resin bonded C~N wheels.
British Patent 834,351, published in 1960 teaches the use of metal sulfides together with alkali-metal salts such as sulfates as fillers in conventional abrasive wheels for qrindinq alloy steels. While the pat~nt refers to 15 abrasives generally, and lists diamond, such fillers, so far as is known, have never been commercially employed in diamond wheels or in CBN wheels.
Gerrnan Patent P2230701, to Winter h Sohn discloses employinq zinc sulfide with cryolite as a ~rinding aid in 20 stick form to be applied to the workpiece. No suq~estion of incorporatinq the qrindinq aids in the wheel bond appears in the patent.
_MMARY OF THE INVENTION
The present invention is the inclusion in CBN
25 orqanic resin bonded wheels of an iron sulfide filler together with sodium or potassium sulfate. Somewhat inferior to the iron sulfide/alkali sulfate filler are cryolite, or potassium aluminum tetrafluoride, or hexafluoride, in the amount of 8 to 50% bv volume of the qrinding section of the 30 toolO Obviously, combinations of these fillers can be employed. Such wheels, in dry qrinding of tool steels, or qrinding of tool steels in combination with cemented carbides~ show equivalent or better results than the best prior art wheels usinq hond compositions containing silver 35 and drv film lubricants. Elimination of the need for silver is a ma~or economic henefit. These wheels also are advantaqeous in providing qreater freeness of cut and thus more rapid cut of the workpiece.
()3 DE'~\ILF.D DE~ CRIP'rION OF THE INVF.NTION
Wheels according to the present invention may be prepared as followsO
Wheel Pre~aration An intimate mixture of fillers and the csN abrasive is prepared. Fillers are those active materials included as the suh~ect of the application as well as other inert substances. The mixture is then coated with a liquid pickup aqent. A finely divided powdered resin is then mixed with 10 the liquid coated abrasive/filler mixture so as to coat the surfaces of the abrasive and filler particles evenly with resin. In the usual practice, phenolic novolak resin with hexamethylene tetramine crosslinking aqent is chosen as the resin and furfural as the liquid pickup agent.
A typical formulation which illustrates the invention is:
InqredientPercent bv Volume FeS2 11 .SiC 8 Furfural 2 Resin 38 CaO 2 This mixture is then distributed evenly in a groove molded or machined around the circumference of a core. The core is composed of finely divided aluminum powder and resin which has previously been compressed either cold or hot. The wheel, which now consists of the core and circumferentially 30 located abrasive section, is hot pressed to melt and fuse the resin bondinq both the abrasive section and the core.
Pressures to 50 tsi and temperatures from 140 to 200c are applied to the wheel during a period of one-~uarter to one hour to form the wheei Subsequent to this operation the 35 wheel may be heated to a temDerature higher than the molding temperature at at~ospheric pressure to improve grinding characteristics. Finally, the ~heel is machined to prepare a product to standard and fixed dimensional specifications.
~8~
f)ther thermosetti.llg resins or e~uival.ents can be e,lPloyed. The wheels may be straight cyli~drical wheels (lAl shape), or may be cup wheels as in the example above, or mav be any other conventional shape.
S The active filler should be present in a total amount of ~rom 8% to 50% by volume of the qrinding section of the wheel. The ratio of FeS2 to alkali sulfate may be from 4/1 to 1/4 by volume, but is preferably from 40/60 to ~0/40 by volume. Sodium sulfate may replace all or part of the 10 ~254'
Claims (2)
1. A resin bonded grinding wheel containing cubic boron nitride abrasive grits characterized in that the resinous bonding matrix contains a filler selected from the group consisting of (1) iron sulfide and an alkali sulfate in a volume ratio of 1/4 to 4/1, (2) cryolite, (3) potassium aluminum fluoride, and mixtures thereof, in the amount of 8 to 50% by volume of the abrasive, bond, and filler combination.
2. A resin bonded grinding wheel containing cubic boron nitride abrasive grits characterized in that the resinous bonding matrix contains, as filler, finely divided iron sulfide and alkali sulfate in a volume ratio of 1/4 to 4/1 in the amount of 8 to 50% by volume of the abrasive, bond, and filler combination.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US24585581A | 1981-03-20 | 1981-03-20 | |
US245,855 | 1981-03-20 |
Publications (1)
Publication Number | Publication Date |
---|---|
CA1188103A true CA1188103A (en) | 1985-06-04 |
Family
ID=22928362
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA000396042A Expired CA1188103A (en) | 1981-03-20 | 1982-02-11 | Cbn grinding wheel |
Country Status (9)
Country | Link |
---|---|
EP (1) | EP0061035A3 (en) |
JP (1) | JPS57163067A (en) |
AU (1) | AU8080082A (en) |
BR (1) | BR8201393A (en) |
CA (1) | CA1188103A (en) |
DE (1) | DE61035T1 (en) |
ES (1) | ES8308245A1 (en) |
IN (1) | IN155234B (en) |
ZA (1) | ZA821215B (en) |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2540770B1 (en) * | 1983-02-14 | 1987-12-11 | Norton Co | CUBIC BORON NITRIDE GRINDING |
AT394961B (en) * | 1987-07-17 | 1992-08-10 | Bbu Chemie Gmbh | HALOGENIC FILLERS FOR ABRASIVE BODIES, METHOD FOR PRODUCING THESE FILLERS AND THE ABRASIVE BODIES CONTAINING THEM |
US5061295A (en) * | 1990-10-22 | 1991-10-29 | Norton Company | Grinding wheel abrasive composition |
US5269821A (en) * | 1992-02-20 | 1993-12-14 | Minnesota Mining And Manufacturing Company | Coatable mixtures including erodable filler agglomerates, methods of preparing same, abrasive articles incorporating cured versions of same, and methods of making said articles |
EP1704965A1 (en) * | 2005-03-24 | 2006-09-27 | Solvay Fluor GmbH | Grinding aid |
CN102059659A (en) * | 2009-11-13 | 2011-05-18 | 沈阳中科超硬磨具磨削研究所 | Formula system for abrasive layer of resin cubic boron nitride (CBN) end face grinding wheel |
CN113059506A (en) * | 2021-03-08 | 2021-07-02 | 天津职业技术师范大学(中国职业培训指导教师进修中心) | Glass powder sintered solid self-lubricating grinding wheel and preparation method thereof |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB834351A (en) * | 1957-10-25 | 1960-05-04 | Abrasive & Metal Products Comp | Improvements in or relating to abrasives |
FR1330483A (en) * | 1961-08-16 | 1963-06-21 | Carborundum Co | Abrasive wheels |
GB1472044A (en) * | 1975-08-27 | 1977-04-27 | Inst Material Akad Nauk Ukrain | Composition for manufacturing abrasive tools |
FR2385494A1 (en) * | 1977-03-30 | 1978-10-27 | Norton Co | Precision abrasive grinding wheels giving high surface finish - using a binder contg. epoxy! resin and phenol! resin as replacement for shellac |
US4110939A (en) * | 1977-06-13 | 1978-09-05 | The Carborundum Company | Cuprous oxide containing resin bonded abrasive article and process for manufacturing same |
JPS54163492A (en) * | 1978-06-15 | 1979-12-26 | Toa Seito Kougiyou Kk | Polishing body and its preparation |
US4253850A (en) * | 1979-08-17 | 1981-03-03 | Norton Company | Resin bonded abrasive bodies for snagging metal containing low abrasive and high filler content |
-
1982
- 1982-02-11 CA CA000396042A patent/CA1188103A/en not_active Expired
- 1982-02-24 ZA ZA821215A patent/ZA821215B/en unknown
- 1982-02-25 AU AU80800/82A patent/AU8080082A/en not_active Abandoned
- 1982-03-01 IN IN233/CAL/82A patent/IN155234B/en unknown
- 1982-03-04 EP EP82101696A patent/EP0061035A3/en not_active Withdrawn
- 1982-03-04 DE DE198282101696T patent/DE61035T1/en active Pending
- 1982-03-12 ES ES510379A patent/ES8308245A1/en not_active Expired
- 1982-03-15 JP JP57039607A patent/JPS57163067A/en active Pending
- 1982-03-15 BR BR8201393A patent/BR8201393A/en unknown
Also Published As
Publication number | Publication date |
---|---|
AU8080082A (en) | 1982-09-23 |
IN155234B (en) | 1985-01-12 |
JPS57163067A (en) | 1982-10-07 |
BR8201393A (en) | 1983-02-01 |
EP0061035A2 (en) | 1982-09-29 |
EP0061035A3 (en) | 1983-07-27 |
ZA821215B (en) | 1983-01-26 |
ES510379A0 (en) | 1983-08-16 |
ES8308245A1 (en) | 1983-08-16 |
DE61035T1 (en) | 1983-07-21 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
MKEX | Expiry |