Abstract
TiAI electrode was made by sintering of CIPed compact with Ti and Al mixed powder at the temperature of 1673K. The electrode made by this method was composed of fully lameller structure of Ti3Al and TiAl intermetallic compounds without a trace of Ti or Al metallic residue.
As the results of testing this electrode for plasma rotating electrode process (PREP) in helium gas atmosphere, it was seen that powders obtained have the same properties, such as particle sphericity, particle size distribution and chemical compositions, as powders produced by using the electrode prepared from the melting ingot. PREPed Ti-Al powders consist of two kinds of particles being different in micro-structure, but thesame compositional ratio of Ti to Al, the one has a dendritic surface (D Powder) and the other has a surface relief (M Powder), of which the micro-structure shows α2 single phase and is suitable for the compact forming by hot pressing compared to that of D powders.
In this work, M particles being distinguished by SEM surface micro-structure were observed in the finer side of the particle size distribution and presumed that one ofthe facter to produce the M powder is a cooling rate on PREP.
