Preparation of Micro-spherical Titanium Powder by RF Plasma

Abstract:

Spherical micro-sized titanium powder was synthesized by (RF) plasma with large TiH2 powder as starting material. The phase, morphology and particle size distribution of the powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and laser micron sizer (LMS), respectively. The dehydrogenation, hydrogen decrepitation and spheroidization of TiH2 feedstock take place in one-step by RF plasma processing and the prepared spherical powder possesses favorable dispersity and smooth surface. The prepared fine spherical powder is composed of Ti and residual TiH. Pure single-phase spherical titanium powder is obtained after further vacuum (1.3×10-4 Pa) dehydrogenation treatment at 750 oC for 2 h. The average size of Ti powder is reduced from 100~150 μm of TiH2 powders to 20~50 μm after the treatment in the plasma. The spheroidization efficiency is almost 100% at feeding rate of 15 g/min. The RF plasma-assisted argon dehydrogenation and decomposition of TiH2 is an ideal route for large-scale synthesis of well- spherical metallic titanium powder.

Key words:RF plasma; spherical titanium powder; dehydrogenation; spheroidization