Microstructure and mechanical properties of laser butt welds of selective laser melted Ta10W alloy plates with different forming directions

This study investigates the anisotropy effect of Ta10W alloy manufactured by selective laser melting (SLM) on the microstructure and mechanical properties of the three butt welds. The welds were characterized by formation, microstructure, microhardness, room temperature (RT) strength, high temperature (HT) strength, and fracture morphology. Re-sults indicate that Ta10W manufactured by SLM exhibits anisotropy in microstructure and properties, leading to notable differences in the welds' microstructure and mechanical properties. When the base metal's X-axis aligns with the welding direction, the weld forms columnar sub-grains, whereas aligning the base metal's Z-axis with the welding direction results in equiaxed sub-grains in the weld. These distinct microstructures influence the maximum RT strength, with the X + X weld displaying significantly higher strength (751.33 MPa) compared to the X + Z (672.00 MPa) and Z + Z (667.25 MPa) welds. Fracture analysis reveals a transition from cleavage fracture to intergranular fracture in three welds. The microhardness and HT strength of the welds exhibit an inapparent difference, with the microhardness of approximately 305 HV0.2/15 and the HT (1800 degrees C) strength of around 110.50 MPa.(c) 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

This study investigates the anisotropy effect of selective laser melting (SLM)-manufactured Ta10W alloy on the microstructure and mechanical properties of welds. The results reveal notable differences in microstructure and mechanical properties due to the anisotropy of the Ta10W alloy. The base metal's alignment with the welding direction affects the welds' microstructure and maximum room temperature strength.