| 摘要 |
<p>Alpha-SiC powder is heated in vacuo to above 1200 deg. C. It is then mixed with boron and a prod. contg. carbon, and is sintered in a neutral atmos. at ca. 2100 deg.C. In the pref. process, alpha-SiC powder and boron powder are milled with a volatile organic liq. in a mill contg. steel balls, and then drying the mixt. The mixt. is leached with HCl; washed with water; and next heated in vacuo at above 1200 deg.C, followed by adding a phenolic lacquer dissolved in a solvent, pressing, and sintering. The vacuum heating of the mixt. is pref. at 1200-1600,(esp. 1600) deg.C, and 1 torr.. Sintered prods. can be obtd. with a density of 90-98% of the theoretical density of SiC, and with a modulus of rupture at 1400 deg.C. of above 400 MPa using three-point flexure.</p> |
