Patent US2360518A successfully refreshed from Google Patents.
Patent US4820663A successfully refreshed from Google Patents.
US4820663A
Expired / Lapsed
US
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Whisker reinforced ceramic and a method of clad/hot isostatic pressing same
Assignee: Kennametal PC Inc
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Filing: 1987-09-02
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Granted: 1989-04-11
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Expires: 2007-09-02
Abstract
Abstract A method of manufacturing a shaped ceramic article by hot isostatic pressing comprising the following steps: (a) forming a compact of sinterable ceramic compositions, (b) applying a coating to the compact by vapor deposition of a ceramic composition that does not become vitreous before or during the subsequent isostatic pressing step, and (c) heating and isostatically pressing the coated compacts in an atmosphere that reacts with the coating and/or the compact at pressing temperatures and pressures to cause the compact to approach theoretical density. The method is suitable for forming a fired ceramic compact having a whisker loading in excess of about 12.5 volume percent with substantially isotropic properties due to a substantially random orientation of the whiskers.
Inventors
- 👤 Pankaj K. Mehrotra
- 👤 Joyce L. Swiokla
- 👤 Elizabeth R. Billman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:19
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; B; B23; B23B; B23B27/00; B23B27/14; B23B27/148; C04B35/00; C04B35/01; C04B35/10; C04B35/111; C04B35/117; C04B35/119; C04B35/16; C04B35/18; C04B35/185; C04B35/515; C04B35/56; C04B35/563; C04B35/58; C04B35/584; C04B35/597; C04B35/622; C04B35/64; C04B35/645; C04B35/6455; C04B35/71; C04B35/78; C04B35/80; C04B41/45; C04B41/50; C04B41/5053; C04B41/5062; C04B41/52; C04B41/80; C04B41/81; C04B41/85; C04B41/87; C04B41/89; B23B2228/00; B23B2228/61; C04B2235/00; C04B2235/02; C04B2235/30; C04B2235/32; C04B2235/3205; C04B2235/3206; C04B2235/3224; C04B2235/3225; C04B2235/50; C04B2235/52; C04B2235/5208; C04B2235/5216; C04B2235/524; C04B2235/5244; C04B2235/526; C04B2235/5264; C04B2235/5276; C04B2235/5296; C04B2235/54; C04B2235/5418; C04B2235/5445; C04B2235/60; C04B2235/608; C04B2235/70; C04B2235/74; C04B2235/77
Claims Analysis
Total Claims: 56
Claim 1
Independent Claim
110 words
A method of achieving a density greater than 95% of theoretical in a shaped ceramic article incorporating a ceramic whisker phase therein by hot isostatic pressing comprising the steps of (a) forming a compact substrate of sinterable ceramic composition having at least 5 volume percent ceramic whiskers therein, (b) applying a coating to the compact substrate by vapor deposition of a ceramic composition that does not become vitreous before or during the subsequent isostatic pressing step, and (c) heating and isostatically pressing the coated compact substrate in an atmosphere that reacts with the coating and/or the compact substrate at temperatures and pressures to cause the compact to approach theoretical density.
Claim 2
Independent Claim
110 words
A method of achieving a density greater than 95% of theoretical in a shaped ceramic article incorporating a ceramic whisker phase therein by hot isostatic pressing comprising the steps of (a) forming a compact substrate of sinterable ceramic composition having at least 5 volume percent ceramic whiskers therein, (b) applying a coating to the compact substrate by vapor deposition of a ceramic composition that does not become vitreous before or during the subsequent isostatic pressing step, and (c) heating and isostatically pressing the coated compact substrate in an atmosphere that reacts with the coating and/or the compact substrate at temperatures and pressures to cause the compact to approach theoretical density.
Claim 3
Independent Claim
107 words
A method of achieving a density greater than 95% of theoretical in a shaped ceramic article incorporating a carbide whisker phase therein by hot isostatic pressing comprising the steps of (a) forming a compact substrate of sinterable ceramic composition having at least 5 volume percent carbide whiskers therein, (b) applying a coating to the compact substrate by vapor deposition of a ceramic composition that does not become vitreous before or during the subsequent isostatic pressing step, and (c) heating and isostatically pressing the coated compact substrate in an atmosphere that reacts with the compact substrate at temperatures and pressures to cause the compact to approach theoretical density.
Claim 4
Independent Claim
107 words
A method of achieving a density greater than 95% of theoretical in a shaped ceramic article incorporating a carbide whisker phase therein by hot isostatic pressing comprising the steps of (a) forming a compact substrate of sinterable ceramic composition having at least 5 volume percent carbide whiskers therein, (b) applying a coating to the compact substrate by vapor deposition of a ceramic composition that does not become vitreous before or during the subsequent isostatic pressing step, and (c) heating and isostatically pressing the coated compact substrate in an atmosphere that reacts with the compact substrate at temperatures and pressures to cause the compact to approach theoretical density.
Claim 5
Dependent Claim
20 words
The method according to claim 2 wherein the carbide whiskers comprise 5 to 40 volume percent of the compact substrate.
Claim 6
Dependent Claim
20 words
The method according to claim 2 wherein the carbide whiskers comprise 10 to 35 volume percent of the compact substrate.
Claim 7
Dependent Claim
23 words
The method of according to claim 2 wherein the carbide whiskers are selected from the group consisting of silicon carbide and titanium carbide.
Claim 8
Independent Claim
146 words
A method of achieving a density greater than 95% of theoretical in a ceramic cutting tool insert incorporating a ceramic whisker phase therein by hot isostatic pressing comprising the steps of (a) forming a compact substrate of sinterable ceramic composition having at least 5 volume percent ceramic whiskers therein substantially in the desired shape of the cutting tool, (b) applying a coating to the compact substrate by vapor deposition of a ceramic composition that does not become vitreous before or during the subsequent isostatic pressing step, and (c) heating and isostatically pressing the coated compacts in an atmosphere that reacts with the coating and/or the compact substrate at temperatures and pressures to cause the compact to approach theoretical density, and (d) grinding away the coating adhering to the isostatically pressed compact and further shaping the compact in the shape of a cutting tool insert if required.
Claim 9
Independent Claim
146 words
A method of achieving a density greater than 95% of theoretical in a ceramic cutting tool insert incorporating a ceramic whisker phase therein by hot isostatic pressing comprising the steps of (a) forming a compact substrate of sinterable ceramic composition having at least 5 volume percent ceramic whiskers therein substantially in the desired shape of the cutting tool, (b) applying a coating to the compact substrate by vapor deposition of a ceramic composition that does not become vitreous before or during the subsequent isostatic pressing step, and (c) heating and isostatically pressing the coated compacts in an atmosphere that reacts with the coating and/or the compact substrate at temperatures and pressures to cause the compact to approach theoretical density, and (d) grinding away the coating adhering to the isostatically pressed compact and further shaping the compact in the shape of a cutting tool insert if required.
Claim 10
Dependent Claim
20 words
The methods according to claims 1, 2, or 6 wherein the coating is titanium nitride applied by chemical vapor deposition.
Claim 11
Dependent Claim
16 words
The method according to claim 6 wherein the coating is between 5 and 50 microns thick.
Claim 12
Dependent Claim
16 words
The method according to claim 6 wherein the gas used during hot isostatic pressing is nitrogen.
Claim 13
Dependent Claim
31 words
The methods according to claims 1, 2, or 6 wherein the heating and isostatic pressing take place in a nitrogen atmosphere at pressures exceeding 10,000 psi and temperatures exceeding 1500° C.
Claim 14
Dependent Claim
32 words
The methods according to claims 1, 2, or 6 wherein an additional sintering step near atmospheric pressures and in a neutral or reactive atmosphere is performed before the hot isostactic pressing step.
Claim 15
Dependent Claim
18 words
The methods according to claims 1, 2, or 6 wherein the compact comprises powdered oxides and carbide whiskers.
Claim 16
Dependent Claim
28 words
The method according to claim 12 wherein the compact comprises powdered alumina and the carbide whiskers are selected from the group consisting of titanium carbide and silicon carbide
Claim 17
Dependent Claim
20 words
The methods according to claims 1, 2, or 6 wherein the coating deposited by chemical vapor deposition is a nitride.
Claim 18
Dependent Claim
30 words
The methods according to claims 1, 2, or 6 wherein the vapor depositions of the coating is brought about by chemical vapor deposition, physical vapor deposition or a combination thereof.
Claim 19
Dependent Claim
28 words
The methods according to claims 1, 2, or 6 wherein multiple layered coatings are applied to the compact and wherein each of said layers have a different composition.
Claim 20
Dependent Claim
31 words
The method according to claim 17 wherein the layer of the coating adjacent the compact substrate has a coefficient of thermal expansion intermediate that of the compact the next adjacent coating.
Claim 21
Dependent Claim
30 words
The method according to claim 17 wherein the layer of the coating adjacent the compact substrate is 2-4 microns thick and is comprised of alumina applied by chemical vapor deposition.
Claim 22
Dependent Claim
19 words
The method according to claim 6 wherein said sinterable ceramic composition contains 25 to 40 volume percent ceramic whiskers.
Claim 23
Dependent Claim
19 words
The method according to claim 6 wherein said sinterable ceramic composition contains 25 to 35 volume percent ceramic whiskers.
Claim 24
Dependent Claim
27 words
The method according to claim 1, 2, 6 or 20 wherein said method achieves a density of greater than 97% theoretical density in said shaped ceramic article.
Claim 25
Independent Claim
25 words
The method according to claims 1 or 20 wherein said method achieves a density of greater than 97% theoretical density in said shaped ceramic article.
Claim 26
Independent Claim
147 words
A method of achieving a density greater than 95% of theoretical in a shaped ceramic article incorporating a carbide whisker phase therein by hot isostatic pressing comprising the steps of (a) forming a compact of sinterable alumina based ceramic composition having at least 20 volume percent carbide whiskers selected from the group consisting of titanium carbide and silicon carbide therein, (b) heating the compact at near atmospheric pressures to presinter the compact in argon atmosphere, (c) applying a titanium nitride coating to the presintered compact by chemical vapor deposition at about 1000° C. which coating does not become vitreous before or during the subsequent isostatic pressing step, and (d) heating and isostatically pressing the coated compacts in a nitrogen atmosphere that reacts with the compact substrate at temperatures and pressures in excess of 1500° C. and 10,000 psi respectively to cause the compact to approach theoretical density.
Claim 27
Independent Claim
147 words
A method of achieving a density greater than 95% of theoretical in a shaped ceramic article incorporating a carbide whisker phase therein by hot isostatic pressing comprising the steps of (a) forming a compact of sinterable alumina based ceramic composition having at least 20 volume percent carbide whiskers selected from the group consisting of titanium carbide and silicon carbide therein, (b) heating the compact at near atmospheric pressures to presinter the compact in argon atmosphere, (c) applying a titanium nitride coating to the presintered compact by chemical vapor deposition at about 1000° C. which coating does not become vitreous before or during the subsequent isostatic pressing step, and (d) heating and isostatically pressing the coated compacts in a nitrogen atmosphere that reacts with the compact substrate at temperatures and pressures in excess of 1500° C. and 10,000 psi respectively to cause the compact to approach theoretical density.
Claim 28
Dependent Claim
69 words
A fired ceramic composition comprising a matrix phase and a carbide whisker phase, and a nitrogen containing phase formed as a reaction product of said carbide whisker phase with nitrogen, said carbide whisker phase forming 25 to 40 volume percent of said fired ceramic composition, the X-ray parameter of whisker orientation being within the range 0.66 to 1.5, and the density of the fired ceramic exceeding 95 percent theoretical.
Claim 29
Dependent Claim
69 words
A fired ceramic composition comprising a matrix phase and a carbide whisker phase, and a nitrogen containing phase formed as a reaction product of said carbide whisker phase with nitrogen, said carbide whisker phase forming 25 to 40 volume percent of said fired ceramic composition, the X-ray parameter of whisker orientation being within the range 0.66 to 1.5, and the density of the fired ceramic exceeding 95 percent theoretical.
Claim 30
Dependent Claim
27 words
The fired ceramic composition according to claim 21 wherein the carbide whisker phase is selected from the group consisting of silicon carbide whiskers and titanium carbide whiskers.
Claim 31
Dependent Claim
40 words
The fired ceramic composition according to claim 21 wherein the carbide whisker phase comprises 25 to 35 volume percent of said fired ceramic composition and said carbide whiskers are selected from the group consisting of silicon carbide and titanium carbide.
Claim 32
Dependent Claim
17 words
The fired ceramic composition according to claim 21 wherein the matrix phase comprises oxide ceramics including alumina.
Claim 33
Dependent Claim
34 words
The fired ceramic composition according to claim 24 wherein the matrix phase comprises a ceramic material selected from the group consisting of high purity alumina, mullite, alumina-zirconia mixtures, sialons, silicon nitride and boron carbide.
Claim 34
Dependent Claim
30 words
The fired ceramic composition according to claims 25 or 26 wherein the carbide whiskers have a length between 20 and 150 microns and a diameter between 0.3 and 1.7 microns.
Claim 35
Dependent Claim
23 words
The fired ceramic composition according to claim 24 wherein the X-ray parameter of whisker orientation is in the range of 0.8 to 1.25.
Claim 36
Dependent Claim
19 words
The fired ceramic composition according to claim 21 wherein the density of the fired ceramic exceeds 97 percent theoretical.
Claim 37
Dependent Claim
95 words
A cutting tool comprising: a fired ceramic composition having a matrix phase, a ceramic whisker phase and a nitrogen containing phase formed as a reaction product of said ceramic whisker phase with nitrogen; said ceramic whisker phase forming 25 to 40 volume percent of said fired ceramic composition; and wherein the x-ray parameter of whisker orientation being within the range of 0.66 to 1.5; the density of said fired ceramic composition exceeding 95 percent theoretical; and said fired ceramic composition having a cutting edge at a juncture of a rake face and a flank face.
Claim 38
Dependent Claim
95 words
A cutting tool comprising: a fired ceramic composition having a matrix phase, a ceramic whisker phase and a nitrogen containing phase formed as a reaction product of said ceramic whisker phase with nitrogen; said ceramic whisker phase forming 25 to 40 volume percent of said fired ceramic composition; and wherein the x-ray parameter of whisker orientation being within the range of 0.66 to 1.5; the density of said fired ceramic composition exceeding 95 percent theoretical; and said fired ceramic composition having a cutting edge at a juncture of a rake face and a flank face.
Claim 39
Dependent Claim
19 words
The cutting tool according to claim 32 wherein the density of said fired ceramic composition exceeds 97 percent theoretical.
Claim 40
Dependent Claim
16 words
The cutting tool according to claim 33 wherein said whisker phase includes a carbide whisker phase.
Claim 41
Dependent Claim
26 words
The cutting tool according to claim 33 wherein said carbide whisker phase is selected from the group consisting of silicon carbide whiskers and titanium carbide whiskers.
Claim 42
Dependent Claim
27 words
The cutting tool according to claim 33 wherein said whisker phase includes carbide whisker phase which forms 25 to 35 volume percent of said first ceramic composition.
Claim 43
Dependent Claim
16 words
The cutting tool according to claim 33 wherein said matrix phase comprises oxide ceramics including alumina.
Claim 44
Dependent Claim
31 words
The cutting tool according to claim 33 wherein the matrix phase comprises a ceramic material selected from the group consisting of alumina, mullite, alumina-zirconia mixtures, sialons, silicon nitride and boron carbide.
Claim 45
Dependent Claim
27 words
The cutting tool according to claim 34 wherein the carbide whiskers having a length between 20 and 150 microns and a diameter between 0.3 and 0.7 microns.
Claim 46
Dependent Claim
22 words
The cutting tool according to claim 33 wherein the x-ray parameter of whisker orientation is in the range of 0.8 to 1.25.
Claim 47
Dependent Claim
15 words
The cutting tool according to claim 33 wherein said matrix phase consists essentially of alumina.
Claim 48
Dependent Claim
15 words
The cutting tool according to claim 40 wherein said matrix phase consists essentially of alumina.
Claim 49
Dependent Claim
33 words
The cutting tool according to claim 30 wherein said whisker phase consists essentially of silicon carbide whiskers and said silicon carbide whiskers form 25 to 35 volume percent of said fired ceramic composition.
Claim 50
Dependent Claim
33 words
The cutting tool according to claim 37 wherein said whisker phase consists essentially of silicon carbide whiskers and said silicon carbide whiskers form 25 to 35 volume percent of said fired ceramic composition.
Claim 51
Dependent Claim
33 words
The cutting tool according to claim 41 wherein said whisker phase consists essentially of silicon carbide whiskers and said silicon carbide whiskers form 25 to 35 volume percent of said fired ceramic composition.
Claim 52
Dependent Claim
33 words
The cutting tool according to claim 42 wherein said whisker phase consists essentially of silicon carbide whiskers and said silicon carbide whiskers form 25 to 35 volume percent of said fired ceramic composition.
Claim 53
Dependent Claim
17 words
The cutting tool according to claim 33 wherein said matrix phase consists essentially of alumina and zirconia.
Claim 54
Dependent Claim
17 words
The cutting tool according to claim 40 wherein said matrix phase consists essentially of alumina and zirconia.
Claim 55
Dependent Claim
17 words
The cutting tool according to claim 37 wherein said matrix phase consists essentially of alumina and zirconia.
Claim 56
Dependent Claim
17 words
The cutting tool according to claim 44 wherein said matrix phase consists essentially of alumina and zirconia.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1992-04-10 | 1992-10-10 | 1993-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-10 | 1996-10-10 | 1997-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-10 | 2000-10-10 | 2001-04-11 | $7700.00 | Window Closed / Lapsed |