TIAL BASED ALLOYS PRODUCED USING ELEMENTAL AND PREALLOYED POWDER-METALLURGY - REACTIVE SINTERING, MODELIZATION AND TRANSFORMATIONS

Titanium aluminide alloys based on gamma-TiAl have an excellent potent ial to become an attractive intermetallic for structural applications. In addition to their low density, their high resistance to oxydation, their good creep properties and their high melting temperature, they offer excellent mechanical properties at high temperatures. The study consists of TiAl producing-technics using powder metallurgy. Depending on the powders used two methods are reported. The first one starts wi th alloyed powders, the other one with elemental powders. It results o n a detailed morphological and microstructural description and microha rdness measurements after thermomechanical and thermical treatments. F EM program has allowed a mechanical analysis of canned extrusion. We c ould thus understand the effect of different can materials and reduce the flow stress of the resulting composite. These different points are helpful for future industrial engineering to produce and transform Ti Al.