Control of droplet transfer during in-situ synthesis of NiTi alloys by dual-wire electron beam additive manufacturing

Abstract

In this paper, the droplet transfer mode during in-situ synthesis of NiTi alloys by dual-wire electron beam additive manufacturing by pure Ni and Ti wires was comprehensively studied. This work shows that the droplet transfer was jointly determined by the droplet transfer distance together with spatial position between two wires and electron beam. By reasonable control of the above factors, an ideal stable continuous liquid bridge transfer mode could be achieved. In this mode, Ni wire and Ti wire could be melted together and form a shared molten pool, which avoids the occurrence of spatter and guarantee the credibility of wire fed amount. Results show that NiTi alloys in-situ synthesized by liquid bridge transfer mode could obtain NiTi alloys with good forming quality and typical phase transformation behavior.