Electron beam welding (EBW) and related heat treatments were carried out on Ti-15V-3Cr-3Sn-3Al (Ti-15-3) alloy plate materials. It was found that the operated parameters in the present EBW process together with suitable heat treatments significantly enhanced the mechanical properties as well as the elongations of the Ti-15-3 weldment, which may provide a promising way for further industrial application. Furthermore, the observed nano size phase of beta, alpha, and here first reported TiCr2 particle, may form from the solid solution matrix of the Ti-15-3 alloy. The possible mechanisms for these phase formation are discussed. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.