| 摘要 |
A dual phase silicon aluminum oxynitride material comprising a first phase Si-Al-O-N, commonly referred to as beta -Si-Al-O-N, and a second phase Si-Al-O-N referred to as alpha -Si-Al-O-N. In addition to the double phase Si-Al-O-Ns, there is included a glassy type material which can formulate up to ten percent by weight of the total composition. The material may be manufactured by forming a polytype material made from reacted alumina, aluminum nitride and silicon nitride. The polytype material may be mixed with further powders of silicon nitride and an oxide of yttrium, lithium or calcium and finally reacted to a double phase Si-Al-O-N material where hardness is increased as the additional alpha -Si-Al-O-N is increased without significantly affecting its strength. The material may be formed in situ by mixing aluminum nitride, alumina, silicon nitride, together with an oxide of yttrium, lithium or calcium. These materials can then be sintered to a final product containing a double phase Si-Al-O-N. Control of the alumina content in the polytype or in situ methods affects the percentage of alpha -Si-Al-O-N produced in the final product. The hardness of the material increases with the alpha -Si-Al-O-N content without significantly affecting its transverse rupture strength.
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