Effect of deposition layer on microstructure of Ti–Al bimetallic structures fabricated by wire and arc additive manufacturing
Yinbao Tian, Junqi Shen, Shengsun Hu, Xinya Chen, Yangchuan Cai, Jian Han
Abstract
Ti–Al bimetallic components present extensive application prospects and have attracted considerable attention owing to their low cost and light weight. In this study, Ti–Al bimetallic structures with one, two, and five Al layers were fabricated via wire and arc additive manufacturing by cold metal transfer welding. During the deposition process of the first Al layer, the matrix was TiAl, and a needle-shaped Ti 3 Al was formed. Subsequently, from the second deposition layer of the Al alloy, however, TiAl 3 was formed, and it exhibited an exceptional morphology with two types of structures: coarse columnar grain structures with identical growth orientation, and long strip-like structures with a random distribution. The formation order of Ti–Al intermetallic compounds was TiAl 3 , TiAl, and Ti 3 Al.