Preparation of directionally solidified B4C-TiB2-SiC ternary eutectic composites by a floating zone method and their properties

Abstract

Directionally solidified B4C-TiB2-SiC composites were prepared by a floating zone method using B4C, TiB2 and SiC as starting materials. The B4C-TiB2-SiC system was ternary eutectic whose eutectic composition was 51.2B4C-8.1TiB 2-40.7SiC (mol%). The ternary eutectic composite showed a lamellar microstructure where B4C(104), TiB2(100) and SiC(111) planes were perpendicular to the growth direction. The Vickers hardness of the B4C-TiB2-SiC ternary eutectic composite was 28 to 32 GPa. The electrical conductivity was 6 to 9 × 104 Sm-1, and the thermal conductivity was 35 to 45 WK-1 m-1 in the temperature range from 298 to 1100K. © 2005 The Japan Institute of Metals.