Microstructural Characteristics and Toughness of Pulsed Electron Beam Weld Metal of Ti-3Al-2Mo-2Zr Titanium Alloy

Pulsed electron beam welding represents a novel energy input mode. The electron beam impinges on the specimen in discrete pulses. This approach reduces overall heat input while enhancing the fusion depth. In this study, Ti-3Al-2Mo-2Zr titanium alloys were welded by varying the pulse frequency and duty cycle. The weld microstructure and toughness of the welds were characterized. The results indicate that the weld metal is primarily composed of martensitic α´ phase. Due to the pronounced pulse effect, the α´ laths width was refined. The residual compressive stress within the weld was reduced. The crack propagation path in impact fractures was shortened. Consequently, the impact toughness decreased. This study elucidates the influence of pulsed electron beam parameters on weld microstructure and toughness.