Directional growth of metastable phase gamma in laser-remelted Ti-Al

Gamma titanium aluminide alloys are sensitive to the forming conditions of the preparation process. Here the directional solidification process with a n ultra-high temperature gradient produced by a laser beam was adopted to p repare a directionally solidified microstructure of metastable phase gamma. The microstructure and phase identification were characterized by SEM, TEM and XRD. The average primary spacing of the laser-remelted slice is approx imately 1.1 mum. This affords a means of tailoring the resultant microstruc ture and phase of Ti-Al alloy parts. (C) 2001 Elsevier Science B.V. All rig hts reserved.