Characterization of directionally solidified B4C-TiB2 composites prepared by a floating zone method

Directionally solidified B4C-TiB2 composites were prepared by a Floating Zone method. TiB2 phase, in a rod shape were continuously connected in the B4C matrix. The c-axes of TiB2 and B4C phases were perpendicular and tilted 22degrees to the growth direction, respectively, The (101) and (1 (2) over bar0) planes of the B4C were in parallel to the (001) and ( 100) planes of TiB2, respectively. The electrical conductivity of the composite parallel to the growth direction (sigma(1)) was greater than monolithic B4C by a factor of 100 to 1000, The thermal conductivity of the composite parallel to the growth direction (K-a) about one and a half times as high as that of B4C. The anisotropy of electrical and thermal conductivity were basically explained by a mixing law using the values of B4C and TiB2. The microhardness of the composite was almost the same as that of B4C. The electric discharge machining of the composite was possible owing to the enhancement of electrical conductivity.