| 摘要 |
A sintered ceramic product having a body comprising silicon carbide and SiAlON polytypoid is provided. The body has at least 40 weight percent silicon carbide and a total of silicon carbide and SiAlON polytypoid of at least 75 weight percent, the balance if any of the body comprising not more than 10 weight percent of a phase substantially comprising silicon or silicon containing material, not more than 10 weight percent of a phase consisting of a reaction product comprising an aluminate and not more than 5 weight percent of a glassy phase. A process for densifying silicon carbide to produce the sintered ceramic product comprises intimately mixing from 40 to 98 weight percent silicon carbide with from 2 to 60 weight percent of powdered source material of aluminium, nitrogen and silicon as well as an oxide material to produce an intimate mixture, forming the intimate mixture into a compact, and heating the compact at a temperature of from 1500 DEG C to 2500 DEG C thereby producing a densified sintered product. In the process, the powdered source material is added to the silicon carbide in such proportions that after said heating the product contains at least 40 weight percent silicon carbide and a second crystalline phase comprising SiAlON polytypoid. |
