Effects of Heat Treatment on the Microstructure and Mechanical Properties of a Dual-Phase High-Entropy Alloy Fabricated via Laser Beam Power Bed Fusion

作者：Xiaojun Tan, Zihong Wang, Haitao Chen, Xuyun Peng, Wei Zhang, Haibing Xiao, Zhongmin Liu, Yu‐Chi Hu, Guo Liang, Qingmao Zhang · 发表于：Micromachines · 年份：2024 · DOI：10.3390/mi15040471 · 被引用次数：5 · 研究领域：High Entropy Alloys Studies、Additive Manufacturing Materials and Processes、High-Temperature Coating Behaviors

To enhance the applicability of dual-phase high-entropy alloys (HEAs) like Fe32Cr33Ni29Al3Ti3, fabricated via laser beam power bed fusion (LB-PBF), a focus on improving their mechanical properties is essential. As part of this effort, heat treatment was explored. This study compares the microstructure and mechanical properties of the as-printed sample with those cooled in water after undergoing heat treatment at temperatures ranging from 1000 to 1200 °C for 1 h. Both pre- and post-treatment samples reveal a dual-phase microstructure comprising FCC and BCC phases. Although heat treatment led to a reduction in tensile and yield strength, it significantly increased ductility compared to the as-printed sample. This strength-ductility trade-off is related to changes in grain sizes with ultrafine grains enhancing strength and micron grains optimizing ductility, also influencing the content of FCC/BCC phases and dislocation density. In particular, the sample heat-treated at 1000 °C for 1 h and then water-cooled exhibited a better combination of strength and ductility, a yield strength of 790 MPa, and an elongation of 13%. This research offers innovative perspectives on crafting dual-phase HEA of Fe32Cr33Ni29Al3Ti3, allowing for tailorable microstructure and mechanical properties through a synergistic approach involving LB-PBF and heat treatment.