CATALYTIC EFFECTS OF VARIOUS METALS AND REFRACTORY OXIDES ON THE GROWTH OF TIC WHISKERS BY CHEMICAL VAPOR-DEPOSITION

The growth of TiC whiskers from the TiCl4-H2-CH4 system was investigated on various metals and refractory oxides. Ni family (Ni, Pd, Pt), Co, Fe, and mullite porcelain substrates were effective for the growth of TiC whiskers. TiC whiskers grew in temperature range of 1050-1400°C on Ni family metals and Co, but at 1300-1450°C on mullite and Fe. TiC whiskers grew preferentially in the <111< direction on mullite, but grew in the <100< and <112< as well as <111< on Ni. The growth rate in the axial direction showed maxima against both TiCl4 and CH4 concentrations on Ni as well as on mullite. At the initial stage of growth, TiC whiskers appear to grow by a VLS mechanism on Ni. The growth on mullite seems to occur by a VS mechanism from the initial stage. © 1979.