Claims
- 1. A homogeneous silicon nitride sintered body having a porosity of 0.5% or less, the sintered body comprising:
- 0.5.about.20 wt % of at least one oxide selected from the group consisting of: 0.1.about.10 wt % rare earth element oxides, 0.1.about.10 wt % ZrO.sub.2, 0.1l18 10 wt % alkaline earth metal oxides and 0.1.about.10 wt % Al.sub.2 O.sub.3, the remainder being silicon nitride;
- a silicon nitride crystalline phase; and
- a grain boundary crystalline phase in a voluminal proportion of 50% or less to an entire grain boundary phase and 5% or less to the silicon nitride crystalline phase.
- 2. The silicon nitride body of claim 1, wherein the silicon nitride body has a maximum pore diameter of 10 .mu.m or less.
- 3. The silicon nitride body of claim 1, wherein the silicon nitride body has a rolling fatigue life of at least 0.1.times.10.sup.7 cycles at a Hertz stress of 60 kg/mm.sup.2.
Priority Claims (2)
Number |
Date |
Country |
Kind |
62-298460 |
Nov 1987 |
JPX |
|
63-44001 |
Feb 1988 |
JPX |
|
Parent Case Info
This is a continuation of application Ser. No. 07/270,966 filed Nov. 14, 1988, now abandoned.
US Referenced Citations (6)
Foreign Referenced Citations (9)
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2258762 |
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DEX |
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JPX |
0123870 |
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JPX |
58-50944 |
Nov 1983 |
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0161377 |
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JPX |
0239363 |
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1097158 |
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JPX |
101519 |
May 1988 |
JPX |
2063302 |
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GBX |
Continuations (1)
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Number |
Date |
Country |
Parent |
270966 |
Nov 1988 |
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