Freeform fabrication of titanium metal by 3D micro welding

A novel freeform fabrication method named 3D micro welding (3DMW) has been developed. It is a combined process of the freeform fabrication method with TIG (tungsten inert gas) welding. The titanium micro beads were investigated with respect to the diameter, height, and contact angle to the titanium substrate as functions of arc discharge current and two different shielding gases. The Ar-4% H2 gas was more effective in preventing oxidization of beads than Ar gas. Simple 3D titanium objects with arch, arabic numerals and pyramidal shapes were formed. Fine needle-like solidification structure of α-phase titanium were developed during bead formation due to the rapid cooling of the melt. The interfaces between a titanium bead and titanium substrate were jointed well without cracks or pores.