CA1292875E - High energy laser beam welded tools - Google Patents
High energy laser beam welded toolsInfo
- Publication number
- CA1292875E CA1292875E CA000615903A CA615903A CA1292875E CA 1292875 E CA1292875 E CA 1292875E CA 000615903 A CA000615903 A CA 000615903A CA 615903 A CA615903 A CA 615903A CA 1292875 E CA1292875 E CA 1292875E
- Authority
- CA
- Canada
- Prior art keywords
- cutting
- metal
- wall
- laser beam
- high energy
- 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 - Lifetime
Links
Landscapes
- Polishing Bodies And Polishing Tools (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A cutting tool for cutting hard materials is provided, having at least one preformed cutting element including an outer cutting portion containing cutting particles of abrasive material bonded and held together by a matrix of metal bonding material and an inner non-cutting metal portion of either the same metal bond matrix or a different metal, laser beam fusion welded to a metal wall portion of a metal support of a different metallic composition by strong laser fusion welded seamless phase of the adjoining portions of the united inner non-cutting and wall portions. Also disclosed is a process for making the cutting tool comprising:
providing a preformed cutting element with an integral inner non-cutting portion and inner mating surface holding, pressing and maintaining the cutting element and the inner mating surface in mating engagement with a mating outer support surface of a wall of a metal support and focusing and directing a high energy laser beam heat source of sufficient capacity at and along an interface of the mating surface at a sufficient rate to alloy and fuse adjoining portions of the inner, non-cutting portion and the wall together into a seamless strong coherent laser beam welded phase (WP) without any visible sign of the original line of demarcation initially created at the interface by the mating surface.
A cutting tool for cutting hard materials is provided, having at least one preformed cutting element including an outer cutting portion containing cutting particles of abrasive material bonded and held together by a matrix of metal bonding material and an inner non-cutting metal portion of either the same metal bond matrix or a different metal, laser beam fusion welded to a metal wall portion of a metal support of a different metallic composition by strong laser fusion welded seamless phase of the adjoining portions of the united inner non-cutting and wall portions. Also disclosed is a process for making the cutting tool comprising:
providing a preformed cutting element with an integral inner non-cutting portion and inner mating surface holding, pressing and maintaining the cutting element and the inner mating surface in mating engagement with a mating outer support surface of a wall of a metal support and focusing and directing a high energy laser beam heat source of sufficient capacity at and along an interface of the mating surface at a sufficient rate to alloy and fuse adjoining portions of the inner, non-cutting portion and the wall together into a seamless strong coherent laser beam welded phase (WP) without any visible sign of the original line of demarcation initially created at the interface by the mating surface.
Description
8'7~
TECHNICAL DISCLOSURE
The invention relates to masonary cutting tools such as diamond and cubic boron nitride saw blades, core drills and drill bits comprised of one or more metal bonded abrasive cutting elements or segments securely joined to a metal core by an intense high energy laser beam fusion welding process that resist higher temperature of and thus enhances the dry cutting ability of the cutting tool.
BACKGROUND OF THE INVENTION
1. Field of the Invention The invention relates to rotary masonary saw blades, core drill and drill bits having at least one metal bonded diamond or cubic boron nitride abrasive cutting element or segment welded to a metal support center core, or shank.
TECHNICAL DISCLOSURE
The invention relates to masonary cutting tools such as diamond and cubic boron nitride saw blades, core drills and drill bits comprised of one or more metal bonded abrasive cutting elements or segments securely joined to a metal core by an intense high energy laser beam fusion welding process that resist higher temperature of and thus enhances the dry cutting ability of the cutting tool.
BACKGROUND OF THE INVENTION
1. Field of the Invention The invention relates to rotary masonary saw blades, core drill and drill bits having at least one metal bonded diamond or cubic boron nitride abrasive cutting element or segment welded to a metal support center core, or shank.
2. Description of the Prior Art The prior art discloses a variety of cutting tools having one or more metal bonded abrasive cutting elements fastened to a metal support, center, core, or shank. One well known and most widely used attachment method is to braze the segment to a metal support center wherein the strength of the joint depends on the brazing material, how well it is applied, ! and how much of it bridges the visible joint or seam at each side of the support. In most instances the brazing material is not as strong, has a lower melting point and is softer than the materials of the segment and support joined thereby. Thus, the brazing material is subjected to erosion by both excess heat and abrasion produced during the cutting process. This is especially true when cutting dry and without the use of coolant that normally reduces the temperature and washes away the abrasive swarf and aggregates in the kerf or cut.
Dry cutting of hard materials without the application of coolant or water to the cutting tool is increasing worldwide because in some instances the coolant or water will contaminate the materials, is undesirable and will freeze in cold weather.
Hence, during prolonged use the erosion causes each side layer or bead of the brazed joint to become progressively softer, thinner and weaker and at some critical point the segment under the stress of centrifugal and operating force is no longer 12~8~75 held to the support by a sufficient amount of brazing material.
The Applicant's invention has solved this weakness by laser beam fusion welding the adjoining material of the segment and support together into a seamless integral mass without the use of additional welding, brazing or soldering material.
Although high energy laser beam welding is known for other applications, the Applicant is unaware of any analogous prior art in which preformed cutting elements containing abrasive particles and a metal bonding material of one composition is laser beam fusion welded to a metal support of a different metallic composition as disclosed and claimed hereinbelow.
S~MMARY OF THE INVENTION
A cutting tool for cutting hard materials has one or more preformed metal bonded abrasive cutting elements, each comprising a molded matrix of known abrasive, diamond or cubic boron nitride cutting particles and metal bond materials high energy laser beam fusion welded to a metal support, center, core, or shank. The cutting particles held in place by the metal bond material are dispersed in an outer cutting portion of each cutting element and adjacent an inner non-cutting metal portion free of cutting particles. The inner non-cutting metal portion has an inner surface adapted for and held in locating mating engagement with an outer mating support surface of the metal support, center, core, or shank during laser beam fusion welding of the adjoining mating portions of the metal support, center, core or shank, and the inner metal portion together into a strong integral unitized and seamless cutting tool. Thus, the invention also provides a method for making unitary cutting tools such as rotary saw blades, core drills and drill bits with metal bonded abrasive cutting elements fusion welded to a drivable metal support, center, core or shank by a fusion welded phase of adjoining metal portions without visible seams and the use of additional welding material and which can withstand the higher temperature dry cutting conditions.
BRIEF DESCRIPTION OF THE DRAWING
Figure 1 is a fragmentary side view of a $egmental abrasive saw blade constructed according to the invention;
~l29Z875 Figure 2 is a perspective view of a cutting element fusion welded to a portion of the metal support center of the saw blade in Figure 1;
Figure 3 is a perspective view of another embodiment of a cutting element having an integral backing portion fusion welded to the metal support;
Figure 4 is a view partly in section of a core drill constructed according to the invention; and Figure 5 is a perspective view of a cutting element fusion welded to the tubular metal support of the core drill in Figure 4.
DESCRIPTION OF THE PREFERRED EMBODIMENTtS) Referring to Figure 1, a segmental rotary abrasive saw blade or cutting tool 10 has a preformed metal support, center or disc 12 including a wall of predetermined diameter and wall thickness usually made of AISI 4130 steel. The steel center 12 has a central hole 14 adapted for receiving a drive means or shaft of a machine on which it will be mounted and rotatably driven. Extending radially inwardly from the outer peripheral surface of the support center 12 are a plurality of radial slots 16 and intervening cutting element support sections 18 of the ! wall including cutting elements 20 thereon angularly spaced about the axis of the center.
Each cutting element support section 18 has an outer peripheral surface initially adapted for locating mating engagement with an inner surface of the preformed cutting element 20 during laser beam fusion welding thereof to the support section 18 of the metal support wall. Each preformed cutting element 20 comprises an outer cutting portion 22 including a plurality of suitably hard abrasive cutting particles 24 dispersed in and held in place by a matrix of metal bonding material 26 extending inwardly to and may include an inner non-cutting metal portion 28 with an inner mating surface.
The metal bond 26 and portion 28 comprises material selected from a group consisting of cobalt, iron, bronze, nickel alloy, tungsten carbide, chromium boride and mixtures thereof.
In Figure 3 there is shown another embodiment of a 12~;~8'75 cutting element 20' in which the inner non-cutting metal portion is an additional integrally formed backing strip or layer 28' of metal totally free of abrasive particles and of a different metallic composition than the metal bonding material 26 and 26' holding the abrasive particles 24 and 24', in outer cutting portions 22 and 22' of the cutting elements 20' and 20'. The metallic backing layer 28' of a different composition is provided when the metallurgical composition of the metal bond 26' is undesirable for obtaining the desired strong fusion or welding of the segment to the metal support. Preferably the composition of the backing layer 28' is selected from a group consisting of iron, nickel alloy, bronze, and mixtures thereof, when the metal bond 26' is cobalt, tungsten carbide, or a mixture thereof.
Typically, an abrasive cutting element or segment 20' will have a metal bond composition 26' consisting by volume of 80% cobalt and 20% tungsten carbide holding 1.1 carats of diamond particles dispersed therein and a metal backing layer 28' simultaneously formed therewith consisting of 65% iron, 25%
nickel alloy, and 10% bronze by volume.
The metal support, center, core, or shank to which the cutting elements 20 and 20' are fused or welded to is usually made of a steel alloy consisting of 0.3% carbon, manganese, silicon and the balance iron.
A typical cutting tool in the ~orm of a rotary abrasive saw blade 10 and about 14" (35.6 cm) in diameter has a steel center 12 initially of about 13.5" (34.3 cm) in diameter, is .095" ~2.38 mm) thick, a 1" (2.54 cm) arbor hole 14, twenty (20) equally spaced radial slots 16 and cutting elements support sections 18 to each of which a cutting element 20 or 20' is laser beam fusion welded.
A typical preformed cutting element or segment 20 or 20' for attachment to the center 12 has an arcuate shape including a convex outer surface, an inner concave mating surface of a radius equal to 1/2 the diameter of the mating convex peripheral surface of the steel center 12, a chord length of 1.937" (4.91 cm), a radial depth between outer and inner lZ~Z~}75 surfaces of 1/4" (6.35 mm) and an axial thickness of .125"
(3.17 mm) that is greater than the wall of the steel center to which it is to be fused. The outer cutting zone or portion containing the abrasive cutting particles has a radial depth sufficiently less than the total radial depth of the cutting segment to provide either the abrasive free inner non-cutting zone or portion 28 or the additional clear backing layer 28' of sufficient radial depth of at least 1/32" (0.8 mm) to prevent the high energy or laser beam from contacting an abrasive particle and hence producing a weaker fused or welded phase WP of the adjoining metals.
When encountered by the heat of the beam the abrasive particles will boil causing the evolution of gas, and hence, porosity and poor alloying of the welded or fused metal and thereby degrading the strength and performance thereof.
Another embodiment of the invention is disclosed in Figure 4 in the form of a rotary core drill 30 comprising a preformed tubular metal or steel support core or shank 32 which may be substantially the same composition as the steel center 12 or AISI 1020 steel and of predetermined axial length adaptable for driving attachment to the drive means of a conventional core drilling motor or machine.
At the opposite end, the steel support tube 32 has an annular wall including an end surface 34 initially adapted for mating locating engagement and fusion welding of one or more cutting elements or segments 40 of arcuate shape thereto.
It is obvious that the preformed cutting elements 20, 20' and 40 may be made in the form of a single continuous annular cutting element not shown but are preferably arcuate segments angularly spaced around the rotational axis and end of the steel center or tube and interrupted by radial or axial slots therebetween.
An arcuate preformed cutting element or segment 40 adapted for fusion welding to the support tube 32 has, as shown in Figure 5, portions constructed in the same manner and of substantially the same material as are the saw blade segments 20 and 20'. Each cutting element 40 comprises an outer cutting 1~2~5 portion 42 including an outer end surface in which a plurality of suitable hard abrasive particles 44 are dispersed and held in place by a matrix of metal bonding material 46 extending axially inwardly to an inner non-cutting metal portion 48 including an inner mating surface.
The metal bonding material holding the hard cutting particles of abrasive in place is formulated from the same materials disclosed above with respect to either the segments 20 and 20'. Likewise, the inner non-cutting portion 48 may be of the same metallic composition as the metal bond 46 or an additional integrally formed clear backing layer of a different metallic composition as taught above with respect to the cutting elements 20 and 20'.
A typical 3" core drill 30 with a 14" (35.56 cm) core length has a steel tube or blank about 14-l/4" (36.22 cm) long with an outside diameter of 3" (7.61 cm), an inside diameter of 2.834" (7.2 cm) and a wall thickness of about .083" (2.1 mm) to the end surface of which four cutting elements 40 are fusion welded to provide the entire cutting crown with an outside diameter of 3.052" (7.74 cm) and an inside diameter of 2.78"
(7.07 cm). Each of the kerf cutting segments 40 has a radial wall thickness of .135" (3.17 mm) an axial length of about 1/4"
(6.35 mm), a chordal length of 1.575" (4 cm), an outer cutting portion and an inner non-cutting portion of substantially the same axial length as the radial depth of the cutting elements 20 and 20'.
The hard cutting particles 24, 24' and 44 of the respective cutting elements 20, 20', and 40, may be of any known abrasive material but are preferably natural or synthetic diamond or cubic boron nitride particles of from 20 to 60 grit size (840 to 250 microns~ with or without a metal coating.
Each of the cutting elements 20, 20' and 40, are preformed by placing a first bottom layer of a mixture of the desired cutting abrasive particles and the metal bonding material in powder form of predetermined depth to form the outer cutting portion in a suitably shaped cavity of a mold designed to produce the desired size and shape of cutting element. A second lZS~375 top layer of either the same metal bonding or a different metallic powdered material, or a preformed metal strip, of sufficient depth to form the inner non-cutting portion of the cutting element is then spread or placed on top of the bottom layer. The mold is then closed and the contents hot pressed at about 1850F (1010 C) for 3 minutes and under 1.5 ton/in2 (20.7 MPa), a temperature sufficient to sinter or fuse the metal strip or powders together and which, upon cooling, provides an integral preformed cutting element or segment of the desired configuration ready for attachment to the support center, core tube, or shank.
One or more of the preformed cutting elements of the desired configuration and the appropriate steel support center, tube core, or shank, are then placed in a fusion welding fixture. The fixture aligns, holds and presses the cutting elements arranged in the desired position so that the inner mating surface of each cutting segment is pressed against an outer mating surface of the steel support center tube, core, or shank. Rotation of the fixture, cutting segments and steel support relative to a stationary laser beam heat source means is begun. Alternatively the fixture, steel support and cutter element, may be held stationary and the laser beam heat source is moved relative thereto.
In either arrangement the high energy laser beam of the heat source is focused on a focal point FP near the mating interface or surfaces of the segment and steel support, and midway through the wall thickness of the steel support.
Typically, the focal point FP may be 0.005 inches radially inward of the steel periphery, and 0.040 inches below the surface (from the incident beam side) of a typical 0.095" (2.4 mm) thick steel core. Exact parameters varies widely with the geometry and chemistry of the steel core and of the cutting segment. The intense heat melts and fuses together the entire thickness of the adjoining inner non-cutting metal portion of the cutting element and the outer portion of the steel support contacted thereby, and the molten volume of the adjoining materials fused together alloys and freezes to a fusion welded phase WP as the beam makes contact with other areas thereof to be fusion welded.
~ 292875 When joining segments to steel greater than 0.095" (2.4 mm) in thickness, and after completion of the welding on one side of the cutting tool, the fusion welding may be repeated on the opposite side of the cutting tool whereby the fusion of the adjoining materials extends substantially through the entire wall thickness of the steel support. Hence, the initial visible seam or line of demarcation between the adjoining inner locating mating surfaces of the cuttlng segment and the steel support, present prior to fusion welding, is substantially eliminated and no longer visible to the naked eye.
In its place is left a narrow band of strong, coherent fusion welded phase WP of the adjoining materials able to resist higher temperatures produced during dry grinding applications and thus prevent loss of cutting elements.
Alternatively, both sides of the cutting tool may be simultaneously fusion welded by placing laser beam heat source means on each side of the cutting tool and focusing each of the beams to penetrate substantially to one half (1/2) the wall thickness of the steel support and thus simultaneously fusion weld opposing side portions of the adjoining materials of the same segment and steel support. One beam may be directed to fusion weld one side of the steel support to one segment and the other beam on the opposite side directed to simultaneous fusion weld a different nonopposing opposite side portion of the steel support and the same cutting element or of another cutting element together.
Following the completion of the fusion welding process the cutting tool may be relieved of stresses produced therein during the fusion welding process. The cutting tool can be stress relieved by the usual process of slowly rotating the cutting tool under a radiant or induction heating coil to anneal the stresses and improve the strength and performance of the fusion welded area.
In comparison to the prior art brazed cutting tools, the cutting tools of the invention have up to three (3) times greater joint strength and withstand higher stresses and temperatures than brazed cutting tools.
i2~%875 As many other embodiments of the invention are possible it is to be understood that the embodiments disclosed in the drawings and described hereinabove are for illustrative purpose only and that the invention includes all modifications and embodiments thereof falling within the scope of the appended claims.
Dry cutting of hard materials without the application of coolant or water to the cutting tool is increasing worldwide because in some instances the coolant or water will contaminate the materials, is undesirable and will freeze in cold weather.
Hence, during prolonged use the erosion causes each side layer or bead of the brazed joint to become progressively softer, thinner and weaker and at some critical point the segment under the stress of centrifugal and operating force is no longer 12~8~75 held to the support by a sufficient amount of brazing material.
The Applicant's invention has solved this weakness by laser beam fusion welding the adjoining material of the segment and support together into a seamless integral mass without the use of additional welding, brazing or soldering material.
Although high energy laser beam welding is known for other applications, the Applicant is unaware of any analogous prior art in which preformed cutting elements containing abrasive particles and a metal bonding material of one composition is laser beam fusion welded to a metal support of a different metallic composition as disclosed and claimed hereinbelow.
S~MMARY OF THE INVENTION
A cutting tool for cutting hard materials has one or more preformed metal bonded abrasive cutting elements, each comprising a molded matrix of known abrasive, diamond or cubic boron nitride cutting particles and metal bond materials high energy laser beam fusion welded to a metal support, center, core, or shank. The cutting particles held in place by the metal bond material are dispersed in an outer cutting portion of each cutting element and adjacent an inner non-cutting metal portion free of cutting particles. The inner non-cutting metal portion has an inner surface adapted for and held in locating mating engagement with an outer mating support surface of the metal support, center, core, or shank during laser beam fusion welding of the adjoining mating portions of the metal support, center, core or shank, and the inner metal portion together into a strong integral unitized and seamless cutting tool. Thus, the invention also provides a method for making unitary cutting tools such as rotary saw blades, core drills and drill bits with metal bonded abrasive cutting elements fusion welded to a drivable metal support, center, core or shank by a fusion welded phase of adjoining metal portions without visible seams and the use of additional welding material and which can withstand the higher temperature dry cutting conditions.
BRIEF DESCRIPTION OF THE DRAWING
Figure 1 is a fragmentary side view of a $egmental abrasive saw blade constructed according to the invention;
~l29Z875 Figure 2 is a perspective view of a cutting element fusion welded to a portion of the metal support center of the saw blade in Figure 1;
Figure 3 is a perspective view of another embodiment of a cutting element having an integral backing portion fusion welded to the metal support;
Figure 4 is a view partly in section of a core drill constructed according to the invention; and Figure 5 is a perspective view of a cutting element fusion welded to the tubular metal support of the core drill in Figure 4.
DESCRIPTION OF THE PREFERRED EMBODIMENTtS) Referring to Figure 1, a segmental rotary abrasive saw blade or cutting tool 10 has a preformed metal support, center or disc 12 including a wall of predetermined diameter and wall thickness usually made of AISI 4130 steel. The steel center 12 has a central hole 14 adapted for receiving a drive means or shaft of a machine on which it will be mounted and rotatably driven. Extending radially inwardly from the outer peripheral surface of the support center 12 are a plurality of radial slots 16 and intervening cutting element support sections 18 of the ! wall including cutting elements 20 thereon angularly spaced about the axis of the center.
Each cutting element support section 18 has an outer peripheral surface initially adapted for locating mating engagement with an inner surface of the preformed cutting element 20 during laser beam fusion welding thereof to the support section 18 of the metal support wall. Each preformed cutting element 20 comprises an outer cutting portion 22 including a plurality of suitably hard abrasive cutting particles 24 dispersed in and held in place by a matrix of metal bonding material 26 extending inwardly to and may include an inner non-cutting metal portion 28 with an inner mating surface.
The metal bond 26 and portion 28 comprises material selected from a group consisting of cobalt, iron, bronze, nickel alloy, tungsten carbide, chromium boride and mixtures thereof.
In Figure 3 there is shown another embodiment of a 12~;~8'75 cutting element 20' in which the inner non-cutting metal portion is an additional integrally formed backing strip or layer 28' of metal totally free of abrasive particles and of a different metallic composition than the metal bonding material 26 and 26' holding the abrasive particles 24 and 24', in outer cutting portions 22 and 22' of the cutting elements 20' and 20'. The metallic backing layer 28' of a different composition is provided when the metallurgical composition of the metal bond 26' is undesirable for obtaining the desired strong fusion or welding of the segment to the metal support. Preferably the composition of the backing layer 28' is selected from a group consisting of iron, nickel alloy, bronze, and mixtures thereof, when the metal bond 26' is cobalt, tungsten carbide, or a mixture thereof.
Typically, an abrasive cutting element or segment 20' will have a metal bond composition 26' consisting by volume of 80% cobalt and 20% tungsten carbide holding 1.1 carats of diamond particles dispersed therein and a metal backing layer 28' simultaneously formed therewith consisting of 65% iron, 25%
nickel alloy, and 10% bronze by volume.
The metal support, center, core, or shank to which the cutting elements 20 and 20' are fused or welded to is usually made of a steel alloy consisting of 0.3% carbon, manganese, silicon and the balance iron.
A typical cutting tool in the ~orm of a rotary abrasive saw blade 10 and about 14" (35.6 cm) in diameter has a steel center 12 initially of about 13.5" (34.3 cm) in diameter, is .095" ~2.38 mm) thick, a 1" (2.54 cm) arbor hole 14, twenty (20) equally spaced radial slots 16 and cutting elements support sections 18 to each of which a cutting element 20 or 20' is laser beam fusion welded.
A typical preformed cutting element or segment 20 or 20' for attachment to the center 12 has an arcuate shape including a convex outer surface, an inner concave mating surface of a radius equal to 1/2 the diameter of the mating convex peripheral surface of the steel center 12, a chord length of 1.937" (4.91 cm), a radial depth between outer and inner lZ~Z~}75 surfaces of 1/4" (6.35 mm) and an axial thickness of .125"
(3.17 mm) that is greater than the wall of the steel center to which it is to be fused. The outer cutting zone or portion containing the abrasive cutting particles has a radial depth sufficiently less than the total radial depth of the cutting segment to provide either the abrasive free inner non-cutting zone or portion 28 or the additional clear backing layer 28' of sufficient radial depth of at least 1/32" (0.8 mm) to prevent the high energy or laser beam from contacting an abrasive particle and hence producing a weaker fused or welded phase WP of the adjoining metals.
When encountered by the heat of the beam the abrasive particles will boil causing the evolution of gas, and hence, porosity and poor alloying of the welded or fused metal and thereby degrading the strength and performance thereof.
Another embodiment of the invention is disclosed in Figure 4 in the form of a rotary core drill 30 comprising a preformed tubular metal or steel support core or shank 32 which may be substantially the same composition as the steel center 12 or AISI 1020 steel and of predetermined axial length adaptable for driving attachment to the drive means of a conventional core drilling motor or machine.
At the opposite end, the steel support tube 32 has an annular wall including an end surface 34 initially adapted for mating locating engagement and fusion welding of one or more cutting elements or segments 40 of arcuate shape thereto.
It is obvious that the preformed cutting elements 20, 20' and 40 may be made in the form of a single continuous annular cutting element not shown but are preferably arcuate segments angularly spaced around the rotational axis and end of the steel center or tube and interrupted by radial or axial slots therebetween.
An arcuate preformed cutting element or segment 40 adapted for fusion welding to the support tube 32 has, as shown in Figure 5, portions constructed in the same manner and of substantially the same material as are the saw blade segments 20 and 20'. Each cutting element 40 comprises an outer cutting 1~2~5 portion 42 including an outer end surface in which a plurality of suitable hard abrasive particles 44 are dispersed and held in place by a matrix of metal bonding material 46 extending axially inwardly to an inner non-cutting metal portion 48 including an inner mating surface.
The metal bonding material holding the hard cutting particles of abrasive in place is formulated from the same materials disclosed above with respect to either the segments 20 and 20'. Likewise, the inner non-cutting portion 48 may be of the same metallic composition as the metal bond 46 or an additional integrally formed clear backing layer of a different metallic composition as taught above with respect to the cutting elements 20 and 20'.
A typical 3" core drill 30 with a 14" (35.56 cm) core length has a steel tube or blank about 14-l/4" (36.22 cm) long with an outside diameter of 3" (7.61 cm), an inside diameter of 2.834" (7.2 cm) and a wall thickness of about .083" (2.1 mm) to the end surface of which four cutting elements 40 are fusion welded to provide the entire cutting crown with an outside diameter of 3.052" (7.74 cm) and an inside diameter of 2.78"
(7.07 cm). Each of the kerf cutting segments 40 has a radial wall thickness of .135" (3.17 mm) an axial length of about 1/4"
(6.35 mm), a chordal length of 1.575" (4 cm), an outer cutting portion and an inner non-cutting portion of substantially the same axial length as the radial depth of the cutting elements 20 and 20'.
The hard cutting particles 24, 24' and 44 of the respective cutting elements 20, 20', and 40, may be of any known abrasive material but are preferably natural or synthetic diamond or cubic boron nitride particles of from 20 to 60 grit size (840 to 250 microns~ with or without a metal coating.
Each of the cutting elements 20, 20' and 40, are preformed by placing a first bottom layer of a mixture of the desired cutting abrasive particles and the metal bonding material in powder form of predetermined depth to form the outer cutting portion in a suitably shaped cavity of a mold designed to produce the desired size and shape of cutting element. A second lZS~375 top layer of either the same metal bonding or a different metallic powdered material, or a preformed metal strip, of sufficient depth to form the inner non-cutting portion of the cutting element is then spread or placed on top of the bottom layer. The mold is then closed and the contents hot pressed at about 1850F (1010 C) for 3 minutes and under 1.5 ton/in2 (20.7 MPa), a temperature sufficient to sinter or fuse the metal strip or powders together and which, upon cooling, provides an integral preformed cutting element or segment of the desired configuration ready for attachment to the support center, core tube, or shank.
One or more of the preformed cutting elements of the desired configuration and the appropriate steel support center, tube core, or shank, are then placed in a fusion welding fixture. The fixture aligns, holds and presses the cutting elements arranged in the desired position so that the inner mating surface of each cutting segment is pressed against an outer mating surface of the steel support center tube, core, or shank. Rotation of the fixture, cutting segments and steel support relative to a stationary laser beam heat source means is begun. Alternatively the fixture, steel support and cutter element, may be held stationary and the laser beam heat source is moved relative thereto.
In either arrangement the high energy laser beam of the heat source is focused on a focal point FP near the mating interface or surfaces of the segment and steel support, and midway through the wall thickness of the steel support.
Typically, the focal point FP may be 0.005 inches radially inward of the steel periphery, and 0.040 inches below the surface (from the incident beam side) of a typical 0.095" (2.4 mm) thick steel core. Exact parameters varies widely with the geometry and chemistry of the steel core and of the cutting segment. The intense heat melts and fuses together the entire thickness of the adjoining inner non-cutting metal portion of the cutting element and the outer portion of the steel support contacted thereby, and the molten volume of the adjoining materials fused together alloys and freezes to a fusion welded phase WP as the beam makes contact with other areas thereof to be fusion welded.
~ 292875 When joining segments to steel greater than 0.095" (2.4 mm) in thickness, and after completion of the welding on one side of the cutting tool, the fusion welding may be repeated on the opposite side of the cutting tool whereby the fusion of the adjoining materials extends substantially through the entire wall thickness of the steel support. Hence, the initial visible seam or line of demarcation between the adjoining inner locating mating surfaces of the cuttlng segment and the steel support, present prior to fusion welding, is substantially eliminated and no longer visible to the naked eye.
In its place is left a narrow band of strong, coherent fusion welded phase WP of the adjoining materials able to resist higher temperatures produced during dry grinding applications and thus prevent loss of cutting elements.
Alternatively, both sides of the cutting tool may be simultaneously fusion welded by placing laser beam heat source means on each side of the cutting tool and focusing each of the beams to penetrate substantially to one half (1/2) the wall thickness of the steel support and thus simultaneously fusion weld opposing side portions of the adjoining materials of the same segment and steel support. One beam may be directed to fusion weld one side of the steel support to one segment and the other beam on the opposite side directed to simultaneous fusion weld a different nonopposing opposite side portion of the steel support and the same cutting element or of another cutting element together.
Following the completion of the fusion welding process the cutting tool may be relieved of stresses produced therein during the fusion welding process. The cutting tool can be stress relieved by the usual process of slowly rotating the cutting tool under a radiant or induction heating coil to anneal the stresses and improve the strength and performance of the fusion welded area.
In comparison to the prior art brazed cutting tools, the cutting tools of the invention have up to three (3) times greater joint strength and withstand higher stresses and temperatures than brazed cutting tools.
i2~%875 As many other embodiments of the invention are possible it is to be understood that the embodiments disclosed in the drawings and described hereinabove are for illustrative purpose only and that the invention includes all modifications and embodiments thereof falling within the scope of the appended claims.
Claims (12)
1. A cutting tool for cutting hard materials adapted for attachment to suitable drive means comprising:
a metal support adapted for attachment to the drive means and having a wall of predetermined size, shape and thickness initially provided with a mating outer support surface of predetermined initial shape;
at least one preformed cutting element high energy laser beam fusion welded to the wall of the metal support and having an outer cutting portion including a plurality of hard cutting particles of abrasive material dispersed in and held in place by a matrix of a metal bonding material and an inner non-cutting metal portion integrally formed with the outer cutting portion, high energy laser beam fusion welded to the wall of the metal support and initially provided with an inner surface of an initial shape adapted for and maintained in locating mating engagement with the outer support surface during fusion welding thereof to the wall of the metal support;
and an integral strong coherent seamless high energy laser beam fusion welded phase of adjoining portions of the inner non-cutting metal portion and the wall of the metal support holding each cutting element to the metal support whereby an initial line of demarcation or seam at the interface initially created by the mating engagement of the initially provided outer support surface of the metal support wall and the initial inner surface of the inner non-cutting portion is no longer visible.
a metal support adapted for attachment to the drive means and having a wall of predetermined size, shape and thickness initially provided with a mating outer support surface of predetermined initial shape;
at least one preformed cutting element high energy laser beam fusion welded to the wall of the metal support and having an outer cutting portion including a plurality of hard cutting particles of abrasive material dispersed in and held in place by a matrix of a metal bonding material and an inner non-cutting metal portion integrally formed with the outer cutting portion, high energy laser beam fusion welded to the wall of the metal support and initially provided with an inner surface of an initial shape adapted for and maintained in locating mating engagement with the outer support surface during fusion welding thereof to the wall of the metal support;
and an integral strong coherent seamless high energy laser beam fusion welded phase of adjoining portions of the inner non-cutting metal portion and the wall of the metal support holding each cutting element to the metal support whereby an initial line of demarcation or seam at the interface initially created by the mating engagement of the initially provided outer support surface of the metal support wall and the initial inner surface of the inner non-cutting portion is no longer visible.
2. A cutting tool according to claim 1 wherein the inner non-cutting portion of the cutting element is of the same metallic composition as the metal bond and of different metallic composition than the adjoining portion of the metal support wall to which it is high energy laser beam fusion welded.
3. A cutting tool according to claim 1 wherein the inner non-cutting portion of the cutting element is of a different metallic composition than the metal bond and the adjoining portion of the wall of the metal support to which it is high energy laser beam fusion welded.
4. A cutting tool according to claim 1 wherein the cutting particles are selected from a group consisting of natural diamond, synthetic diamond, cubic boron nitride, metal coated natural diamond, metal coated synthetic diamond, metal coated cubic boron nitride and mixtures thereof.
5. A cutting tool according to claim 1 wherein the outer cutting portion of each cutting element is of greater thickness and overhangs at least one side of the adjoining portion of the wall to which it is high energy laser beam fusion welded.
6. A cutting tool according to claim 1 wherein the high energy laser beam fusion welded phase of the adjoining portions of the inner non-cutting portion and the wall of the metal support extends through the entire thickness of the wall whereby an initial line of demarcation or seam at the interface initially created by the mating engagement of the initially provided outer support surface of the metal support wall and the initial inner surface of the inner non-cutting portion is no longer visible.
7. A cutting tool according to claim 1 wherein the metallic composition of the adjoining portion of the wall of the metal support high energy laser beam fusion welded to the inner non-cutting portion is a steel alloy comprising carbon, manganese, silicon, and iron.
8. A cutting tool according to claim 1 wherein the metallic composition of the metal bond and the inner non-cutting portion is a material selected from a group consisting of cobalt, tungsten carbide, chromium boride, nickel alloy, bronze alloy, iron, steel alloy, and mixtures thereof.
9. A cutting tool according to claim 1 wherein the inner non-cutting metal portion has a composition consisting of iron, nickel alloy and bronze.
10. A cutting tool according to claim 1 wherein the metal support comprises:
a circular steel center of predetermined wall thickness and initial diameter and about which a plurality of the cutting elements are angularly spaced and high energy laser beam, fusion welded to adjoining portions of the wall and thereby forming a rotary abrasive saw blade.
a circular steel center of predetermined wall thickness and initial diameter and about which a plurality of the cutting elements are angularly spaced and high energy laser beam, fusion welded to adjoining portions of the wall and thereby forming a rotary abrasive saw blade.
11. A cutting tool according to claim 1 whereby the metal support comprises:
a steel tube of predetermined diameter, axial length, wall thickness and about which a plurality of the cutting elements are angularly spaced and high energy laser beam fusion welded to an end portion of the wall and thereby forms a rotary abrasive core drill.
a steel tube of predetermined diameter, axial length, wall thickness and about which a plurality of the cutting elements are angularly spaced and high energy laser beam fusion welded to an end portion of the wall and thereby forms a rotary abrasive core drill.
12. A process of making a cutting tool with at least one high energy laser beam fusion welded preformed cutting element containing abrasive particles bonded together and held in place by a matrix of metallic bonding material to a wall including an outer mating support surface of a metal support comprising:
providing a preformed cutting element with an integrally formed inner non-cutting metal portion free of abrasive particles including an inner mating surface adapted for mating locating engagement with the outer support surface of the wall of the metal support;
holding, pressing and maintaining the cutting element and the inner mating surface thereof in mating engagement with the outer mating support surface of the wall of the metal support, and thus providing a visible seam or line of demarcation at the interface of the mating surfaces;
focusing and directing a high energy laser beam heat source of sufficient capacity at and along the interface of the mating surfaces at a sufficient rate of relative movement to melt, alloy and fusion weld adjoining portions of the inner non-cutting portion of cutting element and the wall of the metal support into an high energy laser beam fusion welded seamless phase thereof without any visible sign of the original seam or line of demarcation at the interface of the mating surfaces.
providing a preformed cutting element with an integrally formed inner non-cutting metal portion free of abrasive particles including an inner mating surface adapted for mating locating engagement with the outer support surface of the wall of the metal support;
holding, pressing and maintaining the cutting element and the inner mating surface thereof in mating engagement with the outer mating support surface of the wall of the metal support, and thus providing a visible seam or line of demarcation at the interface of the mating surfaces;
focusing and directing a high energy laser beam heat source of sufficient capacity at and along the interface of the mating surfaces at a sufficient rate of relative movement to melt, alloy and fusion weld adjoining portions of the inner non-cutting portion of cutting element and the wall of the metal support into an high energy laser beam fusion welded seamless phase thereof without any visible sign of the original seam or line of demarcation at the interface of the mating surfaces.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000615903A CA1292875E (en) | 1983-01-05 | 1990-10-24 | High energy laser beam welded tools |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US45577183A | 1983-01-05 | 1983-01-05 | |
| CA000444629A CA1214984A (en) | 1983-01-05 | 1984-01-04 | High energy laser beam welded tools |
| CA000615903A CA1292875E (en) | 1983-01-05 | 1990-10-24 | High energy laser beam welded tools |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1292875E true CA1292875E (en) | 1991-12-10 |
Family
ID=23810227
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000444629A Expired CA1214984A (en) | 1983-01-05 | 1984-01-04 | High energy laser beam welded tools |
| CA000615903A Expired - Lifetime CA1292875E (en) | 1983-01-05 | 1990-10-24 | High energy laser beam welded tools |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000444629A Expired CA1214984A (en) | 1983-01-05 | 1984-01-04 | High energy laser beam welded tools |
Country Status (1)
| Country | Link |
|---|---|
| CA (2) | CA1214984A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT400543B (en) * | 1993-06-17 | 1996-01-25 | Swarovski Tyrolit Schleif | METAL BONDED ABRASIVE TOOL WITH FILLER |
| CN109822236B (en) * | 2019-04-04 | 2023-11-28 | 中国工程物理研究院机械制造工艺研究所 | Device for cutting and welding pipeline |
-
1984
- 1984-01-04 CA CA000444629A patent/CA1214984A/en not_active Expired
-
1990
- 1990-10-24 CA CA000615903A patent/CA1292875E/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| CA1214984A (en) | 1986-12-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5885149A (en) | Homogenous abrasive tool | |
| US4156329A (en) | Method for fabricating a rotary drill bit and composite compact cutters therefor | |
| JP3372017B2 (en) | Rotary end mill cutter | |
| EP0264674B1 (en) | Low pressure bonding of PCD bodies and method | |
| US4679971A (en) | Rotary cutting tool and process for making same | |
| US5471970A (en) | Method of manufacturing a segmented diamond blade | |
| EP0003116B1 (en) | Composite compact components fabricated with high temperature brazing filler metal, method and apparatus for making same | |
| US20120241224A1 (en) | Polycrystalline diamond compact including a carbonate-catalyzed polycrystalline diamond body and applications therefor | |
| US4319707A (en) | Brazing apparatus to manufacture composite compact components | |
| CN109736712A (en) | Laser welding diamond core bit | |
| CN109736713A (en) | A kind of diamond core bit and its laser welding preparation process | |
| US3590535A (en) | Diamond abrasive saw blade | |
| EP0163914B1 (en) | Method for welding cutter segments | |
| JP2001519722A (en) | Machine tool and manufacturing method thereof | |
| CA1292875E (en) | High energy laser beam welded tools | |
| CA1292876C (en) | Tool component | |
| US5556172A (en) | Brush seal bristle cutting method | |
| US20120159865A1 (en) | Cutting element | |
| AU671022B2 (en) | Brazing | |
| JP4851029B2 (en) | Super abrasive tool with sintered super abrasive tip | |
| WO2001083934A2 (en) | Method for the manufacturing of a cone cutter for rotary drilling by crushing, a rotary cone drill bit, a cone cutter and crushing elements therefore | |
| JP2000108117A (en) | Dry boring diamond drill bit and manufacture thereof | |
| KR100458463B1 (en) | Segment for Diamond Tool and Diamond Tool | |
| CN111922430A (en) | Preparation method of high-bending-strength laser welding diamond saw blade | |
| JPS6260204B2 (en) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| NARE | Reissued | ||
| MKEX | Expiry |