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

Xiaojun Tan; Zihong Wang; Haitao Chen; Xuyun Peng; Wei Zhang; Haibing Xiao; Zhongmin Liu; Yu Hu; Liang Guo; Qingmao Zhang

doi:10.3390/mi15040471

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

Micromachines (Basel). 2024 Mar 29;15(4):471. doi: 10.3390/mi15040471.

Authors

Xiaojun Tan^{1

2

3

4}, Zihong Wang⁵, Haitao Chen², Xuyun Peng², Wei Zhang³, Haibing Xiao³, Zhongmin Liu^{1

4}, Yu Hu^{6

7}, Liang Guo^{1

4}, Qingmao Zhang^{1

4}

Affiliations

¹ Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China.
² Sino-German Intelligent Manufacturing School, Shenzhen Institute of Technology, Shenzhen 518116, China.
³ Intelligent Manufacturing and Equipment School, Shenzhen Institute of Information Technology, Shenzhen 518172, China.
⁴ Guangdong Provincial Key Laboratory of Industrial Ultrashort Pulse Laser Technology, Shenzhen 518055, China.
⁵ College of Materials Science and Engineering, Chongqing University, Chongqing 400045, China.
⁶ School of Locomotive and Vehicle, Guangzhou Railway Polytechnic, Guangzhou 510430, China.
⁷ Guangdong-Hongkong-Macao Joint Laboratory of Energy Saving and Intelligent Maintenance for Modern Transportations, Guangzhou 510430, China.

Abstract

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.

Keywords: dual-phase; heat treatment; high-entropy alloy; laser beam power bed fusion; mechanical property; tailorable microstructure.

Grants and funding

This research was funded by the Natural Science Foundation of Guangdong Province (Grant No. 2023A1515011641), key field research projects in Foshan City (Grant No. 2120001009232), Shenzhen Science and Technology Program (Grant No. GJHZ20220913143012022), Scientific Research Project of General Universities in Guangdong Province (Grant No. 2021KCXTD058), the school-level scientific research project of Shenzhen Institute of Technology (Grant No. 2211017), Guangdong HUST Industrial Technology Research Institute, Guangdong Provincial Key Laboratory of Manufacturing Equipment Digitization (Grant No. 2020B1212060014), the Postdoctoral Science Foundation of China (Grant No. 2022M710503), the Natural Science Foundation Commission of Chongqing (Grant No. CSTB2022NSCQ-BHX0029), Guangdong Basic and Applied Basic Research (Grant No. 2019A1515110360).