摘要 |
A process for making silicon nitride articles of manufacture such as an internal combustion engine valve (2) by providing a homogeneous water-base slurry of silicon nitride powder and at least one nitriding agent and permitting the slurry to age for a time effective to enable a chemical reaction to occur and then reducing the water content sufficiently to form the article and thence forming and nitriding the article using a compound nitriding cycle. |