Fundamental study on wire arc additive manufacturing of commercially pure titanium by robotic metal inert gas welding

Abstract

Wire arc additive manufacturing has been receiving considerable attention as a cost-effective technology for its capability of producing near-net-shape parts directly from feedstock materials, and application to high cost and difficult-to-machine materials, such as titanium, is highly expected. On the other hand, titanium has high reactivity with oxygen or nitrogen at high temperature and this can be detrimental to its mechanical properties. In this study, commercially pure titanium was applied to wire arc additive manufacturing process by robotic metal inert gas welding, and some fundamental experiments with a newly proposed cylindrical type shielding gas nozzle were conducted. From such experimental results, it was shown that equipping the proposed gas shielding nozzle to welding robot could be effective to avoid contamination and characteristic degradation of additively manufactured titanium parts with complex geometry, even though the process is carried out under atmospheric condition.