ANALYSIS OF THE GROWTH MECHANISM OF TiAl_3 WHISKERS PREPARED BY IN SITU REACTION IN MOLTEN ALUMINUM

Some TiAl3 whiskers are found to be produced simultaneously during the formation process of TiB2 Particulates fabricated by in situ reaction in molten aluminum. The thec t of temperature of molten aluminum on the morphologies of the TiAl3 whiskers and the growth mechanism of the whiskers are studied in this paper. The results show that the aspect rutio of the TiAl3 whiskers decreases with the increase of the temperoture. The growth of the whiskers is proved to be controlled by a Vapor-LiquidSoltd (VLS) mechanism. The titanium and aluminum atoms in the catalytic droplet,however, have been coofrmed to react with each othen which is dtherent from other whlskcrs growing by a VLS mcchanism where the compostion in the catalytic droplet is a constant.