TiAl Based Alloys Produced Using Elemental & Prealloyed Powder Metallurgy : Reactive Sintering, Modelisation and Transformations

Abstract
Titanium aluminide alloys based on γ-TiAl have an excellent potential 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 with alloyed powders, the other one with elemental powders. It results on a detailed morphological and microstructural description and microhardness measurements after thermomechanical and thermical treatments. FEM program has allowed a mechanical analysis of canned extrusion. We could 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 TiAl.