Comparison of Ti-5Al-5V-5Mo-3Cr Welds Performed by Laser Beam, Electron Beam and Gas Tungsten Arc Welding

Microstructure and Mechanical Properties of Ti5553 Butt Welds Performed by LBW under Conduction Regime

“…Therefore, taking into account the width and grain size of the welds, it can be stated that LBW-CR is a compensated and interesting welding technology, as it employs an energy density intermediate between arc welding, such as GTAW (high heat input and low power density) and EBW/LBW-KR (relatively low heat input and high power density). CR welds were similar to those previously reported for other welding methods [32]: FZ with a columnar-dendritic-typed grain morphology, HAZ decorated with retained equiaxed β grains (with larger grains at the fusion boundary and smaller grains towards BM) and epitaxial grain growth from the HAZ into the FZ. Table 2 also includes the averaged grain size of the welds zones.…”

“…The narrower weld zones in EBW and LBW-KR samples compared with the LBW-CR and GTAW samples are associated with the higher heat source localization (smaller beam size at the focus position) of the former technologies. The microstructural characteristics of the LBW-CR welds were similar to those previously reported for other welding methods [32]: FZ with a columnar-dendritic-typed grain morphology, HAZ decorated with retained equiaxed β grains (with larger grains at the fusion boundary and smaller grains towards BM) and epitaxial grain growth from the HAZ into the FZ. CR welds were similar to those previously reported for other welding methods [32]: FZ with a columnar-dendritic-typed grain morphology, HAZ decorated with retained equiaxed β grains (with larger grains at the fusion boundary and smaller grains towards BM) and epitaxial grain growth from the HAZ into the FZ.…”

“…The hardness values (HV) follow a similar tendency than those previously obtained with other welding methods [32], i.e., 290-320 HV in the FZ, 300-360 HV in the HAZ and 370-390 HV for BM. The weld zones (FZ and HAZ) had lower hardness values compared with that of the base metal.…”

“…Table 2 summarizes the width and depth of the FZ and HAZ of the LBW-CR welds obtained. For comparison purposes, the results obtained in recent research for Ti5553-Ti5553 butt welds performed with other technologies (GTAW, EBW and LBW-KR with Nd:YAG) [32] are also reported in the table. The widths of the FZ and the HAZ of the GTAW and LBW-CR welds were much wider compared with those of EBW and LBW-KR.…”

“…LBW-CR (HPDL) 4.9 1.3 350 GTAW [32] 5.4 3.0 600 LBW-KR (Nd:YAG) [32] 2.6 0.8 200 EBW [32] 1.7 0.8 200…”