Freeform fabrication of Ti-Al alloys by 3D micro-welding

3D micro-welding (3DMW) is a newly developed rapid prototyping method for metals. It combines a micro-tungsten inert gas (TIG) welding with a layered manufacturing method. A tip of a thin metal wire is melted by a micro-TIG welder to form a small metal bead. By building up metal beads layer by layer under computer control, a 3D metal object is eventually formed. A wide variety of metals and alloys can be used. The Ti-Al based intermetallic alloys have superior mechanical and chemical properties. However, the forming process is difficult and costly. We have tried to fabricate 3D objects of the Ti-Al alloy system by using several thin Ti and Al wires. Some simple objects with a unique microstructure or graded composition are demonstrated.