TIAL-TIGA SECTION OF THE TI-AL-GA SYSTEM

Alloys on the basis of titanium aluminides are very important for mode rn industry. The influence of beta-stabilizer of titanium on the struc ture and properties of Ti-Al alloys has been studied by many authors. The alloying of titanium by alpha-stabilizers has almost not been inve stigated. The purpose of this investigation was to determine the influ ence of gallium on the structure of Ti-Al based alloys at 50 at % Ti. The TiAl-TiGa section has been investigated by means of metallographic , electron microprobe, differential thermal and XRD analyses. The allo ys were prepared by arc-melting from pure metals with an unconsumable tungsten electrode on a water-cooled copper hearth and studied in both as-cast and annealed state. It is shown that continuous solid solutio ns gamma are formed between the equiatomic phases TiAl and TiGa with t he same crystal structure (tetragonal CuAu-type) and similar lattice p arameters. (C) 1998 Elsevier Science S.A.