2002 Volume 43 Issue 9 Pages 2309-2315
Directionally solidified B4C–SiC composites were prepared by a Floating Zone method. The lamellar texture was observed at 53 mol%SiC . The c-axis of B4C phase was tilted 20° to the growth direction. The (102) plane and [\\bar1\\bar21] direction of the B4C phase were parallel to the (311) plane and [12\\bar1] direction of the SiC phase, respectively. The thermal conductivity of the composite parallel to the growth direction (κ||) was about twice as great as that of monolithic B4C . The anisotropy of electrical conductivity and thermal conductivity were explained by a mixing law using the values of B4C and SiC . The mass gain due to oxidation was about 1/3 to 1/5 less than that of monolithic B4C at 1023 K . The surface perpendicular to the growth direction showed slightly better oxidation resistance than that parallel to the growth direction. The microhardness of the composite was almost the same as that of B4C.
