Welding of titanium alloys

¹ Department of Mechanical Engineering, Auckland University of Technology, Auckland, New Zealand
² Department of System Design Engineering, Faculty of Engineering Science, Akita University, Japan
³ Joining & Welding Research Institute, Osaka University, Osaka, Japan
⁴ Institute for Metal Forming, Department of Materials Science and Engineering, Lehigh University, Bethlehem, PA18015, USA

^* e-mail: tpasang@aut.ac.nz

Abstract

This article briefly summarises previous reports as well as some recent results on welding of various titanium alloys. Titanium is available in a wide range, hence, their properties and characteristics (including welding characteristics) may also varied significantly. The alloys studied represented three major areas; they are (1): unalloyed or commercially pure titanium (CP Ti), (2): near α and α+β alloys, and (3): β alloys. From our preliminary results, it can be reported that the structure of fusion zone (FZ) and heat affected zone (HAZ) of alloys from area (1) may change but their hardness remained, arguably, the same as the as-received material. Alloys from area (2) showed an increase in hardness in the FZ and HAZ areas due to the formation of α-prime or martensite, while alloys from area (3) experienced a reduction in hardness associated with dissolution of α phase leaving only retained β in the FZ. Further investigations are required to confirm these findings. Such information are very useful so that appropriate post welding heat treatment (PWHT) can be applied to improve their properties and performance.