Patent EP0081775A2 successfully refreshed from Google Patents.
EP0081775A2
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EP
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Nitrided superhard composite material
Assignee: General Electric Co
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Filing: 1982-12-04
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Granted: —
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Expires: 2002-12-04
Abstract
Abstract Sintered silicon carbide cutting tool composites containing diamond crystals are described. They are made through a process comprising separately compacting carbon binder materials, one of which contains superhard crystals, into a cutting tool insert configuration when the crystals are concentrated in the cutting edges, infiltrating the insert with liquid silicon and sintering and nitriding the insert to convert the silicon to silicon carbide and silicon nitride.
Inventors
- 👤 John Michio Ohno
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 17:17
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/622; C04B35/626; C04B35/62605; C04B35/62625; C04B35/6264; B; B23; B23B; B23B27/00; B23B27/14; B23B27/141; B23B27/145; B23B27/146; B23B27/148; B24; B24D; B24D3/00; B24D3/02; B24D3/04; B24D3/06; C04B35/515; C04B35/52; C04B35/528; C04B35/532; C04B35/56; C04B35/565; C04B35/573; C04B35/63; C04B35/6303; C04B35/6316; C04B37/00; C04B37/001; B23B2226/00; B23B2226/72; C04B2235/00; C04B2235/02; C04B2235/30; C04B2235/38; C04B2235/3817; C04B2235/3826; C04B2235/3852; C04B2235/3873; C04B2235/42; C04B2235/422; C04B2235/424; C04B2235/427; C04B2235/428; C04B2235/46; C04B2235/50; C04B2235/52; C04B2235/5208; C04B2235/5216; C04B2235/524; C04B2235/5248; C04B2235/526; C04B2235/5264; C04B2235/60; C04B2235/616; C04B2235/65; C04B2235/656; C04B2235/70; C04B2235/72; C04B2235/721; C04B2235/74; C04B2235/76; C04B2235/762; C04B2235/80; C04B2237/00; C04B2237/30; C04B2237/32; C04B2237/36; C04B2237/363; C04B2237/365; C04B2237/38; C04B2237/385; C04B2237/50; C04B2237/61; C04B2237/76; C04B2237/86
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
139 words
A process for preparing a bonded composite cutting element (5) comprising: (a) forming a first dispersion (1) of superhard crystals and carbon black in paraffin; (b) forming a second dispersion of carbon fiber, carbon black and filler in paraffin; (c) compacting one of said dispersions (1) to produce a physically stable intermediate compact (2); (d) recompacting said intermediate compact with the remaining dispersion to produce a binary compact (2, 4); (e) subjecting said binary compact to a vacuum for a period of time at a temperature sufficient to vaporize essentially all of said paraffin; (f) infiltrating said binary compact with liquid silicon; and (g). sintering the binary compact containing infiltrated silicon under conditions sufficient to produce a -silicon carbide binder uniting said composite. (h) subjecting said binary compact to a nitriding treatment to convert elemental silicon to silicon nitride.
Claim 2
Dependent Claim
139 words
A process for preparing a bonded composite cutting element (5) comprising: (a) forming a first dispersion (1) of superhard crystals and carbon black in paraffin; (b) forming a second dispersion of carbon fiber, carbon black and filler in paraffin; (c) compacting one of said dispersions (1) to produce a physically stable intermediate compact (2); (d) recompacting said intermediate compact with the remaining dispersion to produce a binary compact (2, 4); (e) subjecting said binary compact to a vacuum for a period of time at a temperature sufficient to vaporize essentially all of said paraffin; (f) infiltrating said binary compact with liquid silicon; and (g). sintering the binary compact containing infiltrated silicon under conditions sufficient to produce a -silicon carbide binder uniting said composite. (h) subjecting said binary compact to a nitriding treatment to convert elemental silicon to silicon nitride.
Claim 3
Dependent Claim
16 words
The process of Claim 1 wherein nitrogen in gaseous form is introduced into the sintering process.
Claim 4
Dependent Claim
12 words
A cutting tool insert (5) made by the processes of Claim 1.
Claim 5
Dependent Claim
32 words
The insert of claim 3 where.the insert includes a layer (6) of superhard crystals on an upper surface and a number of concentrated volumes (8) of superhard crystals project from said layer.
Claim 6
Dependent Claim
35 words
The insert of claim 3 wherein the superhard crystals are concentrated in a rim portion (2) about a central section (4) where the rim portion has a thickness less than the thickness of the insert.
Claim 7
Dependent Claim
19 words
The insert of claim 3 where the superhard crystals are concentrated in a number of cutting edge structures (11).
Claim 8
Dependent Claim
19 words
The insert of claim 3 wherein the cutting edge structures (18) include an underlayer (20) of more dispersed crystals.
Claim 9
Dependent Claim
15 words
The insert of claim 6 wherein the edge structures (11) are projecting from the insert.
Claim 10
Dependent Claim
16 words
The insert of claim 6 wherein the projection is laterally forwardly and upwardly from the matrix.
Claim 11
Dependent Claim
24 words
The invention as recited in claim 6 wherein said insert (15) has a preformed recess (24) in its top or bottom surface or both.
References Cited (Backward Citations)
No citation records indexed.
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