| 摘要 |
<p>A pressureless sintered SiC ceramic composite article having a DC electrical conductivity of at least 0.05 ohmcm-1, a bulk density of at least 2.9 g/cm3 as measured by the Archimedes method, a flexural bend strength of at least 150 MPa as measured by a four-point bend strength test, and capable of exhibiting p-type SiC semiconductor characteristics. The ceramic article comprises 0.5-6.0 wt.% of Al, 0.1-2.0 wt.% of B, the Al being present in at least as great percentage as the B, 0.1-6.0 wt.% of free carbon and at least 90 wt.% of predominantly alpha-phase SiC. Prodn. of the SiC ceramic composite article comprises: (a) milling and blending at least 90 wt.% alpha-phase SiC having a max. particle size of 100 microns with 0.5-6.0 wt.% of at least one Al-contg. additive, 0.1-2.0 wt.% of at least one B-contg. additive, the Al being present in at least as great a percentage as the B, and at least one carbon source material capable of providing free carbon in an amt. of 0.1-6.0 wt.% to produce a raw batch blend, (b) forming and compacting the raw batch blend into a shaped body, and (c) heating the shaped body in an atmos. inert to the SiC, Al-contg. cpd., B-contg. cpd. and free carbon to obtain the pressureless sintered SiC ceramic composite article.</p> |
