Abstract:The mechanism of the reaction between elemental Ti and Al powders in continuous heating was studied through DSC and XRD phase analyses. Results show that, only one exothermic peak appeared on DSC curves for blended elemental Ti and Al powder compacts; and the onset temperature increased with increasing heating rate. After heating to 1 200℃, the main phases of the heating products were Ti3Al and TiAl phases. By kinetic calculation, the apparent activation energy for the exothermic reaction was determined as 340±20kJ/mol. Based on these results, it is suggested that the reaction between elemental Ti and Al powders be a complex one. During this reaction, TiAl3is formed first, finally Ti3Al and TiAl. The rate and intensity of the reaction are inherently dependent on the composition and morphology of raw materials, as well as the heating rate.

Key words: TiAl-based alloy; reaction mechanism; kinetic activation energy