Claims
- 1. A method for enhancing the crystallization rate of high purity fine grain amorphous Si.sub.3 N.sub.4 powder, the method comprising carrying out a crystallization heat treatment of the powder while the powder is in intimate contact with a titanium containing material.
- 2. The method of claim 1 wherein the intimate contact of the Si.sub.3 N.sub.4 powder with the titanium containing material is achieved by the coprecipitation of Si.sub.3 N.sub.4 and TiN formed by the vapor phase reaction of SiCl.sub.4 and TiCl.sub.4 with NH.sub.3.
- 3. The method of claim 1 wherein the intimate contact of the SiCl.sub.4 powder with the titanium containing material is achieved by carrying out the crystallization heat treatment while the powder is in contact with the surface of a refractory inert material containing titanium in a diffusable state.
- 4. The method of claim 1 in which the titanium containing material in intimate contact with the Si.sub.3 N.sub.4 powder is present in an amount corresponding to at least 0.01 weight percent titanium of the total weight of the powder.
- 5. The method of claim 4 in which titanium is present in the amount of from about one half to five weight percent.
Parent Case Info
This application is a division of Ser. No. 526,257, filed Nov. 22, 1974, U.S. Pat. No. 4,145,244.
US Referenced Citations (4)
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Date |
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3110589 |
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Nov 1963 |
|
3959446 |
Mazdiyasni et al. |
May 1976 |
|
3992497 |
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Foreign Referenced Citations (2)
Number |
Date |
Country |
1028977 |
May 1966 |
GBX |
1199811 |
Jul 1970 |
GBX |
Non-Patent Literature Citations (1)
Entry |
Deeley, G. G. et al., "Dense Silicon Nitride", Powd. Met. 8 (1961), pp. 145-151. |
Divisions (1)
|
Number |
Date |
Country |
Parent |
526257 |
Nov 1974 |
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