Designing the heat treatment process for Mg-10Gd-4Y-xZn-0.6Zr (wt.%) alloy: A study on the transformation of microstructure and properties

• Published in: Journal of materials research and technology 2024-05, Vol.30, p.6711-6723
• Main Authors: Li, Mingyu, Zhang, Guangzong, Yin, Siqi, Liu, Xiao, Wang, Changfeng, Guan, Renguo
• Format: Article
• Language: English
• Subjects: Heat treatment; Mechanical properties; Mg-Gd-Y-Zn alloy; Phase transformation; Thermodynamic calculations
• ISSN: 2238-7854
• DOI: 10.1016/j.jmrt.2024.05.073

Heat treatment of Mg10Gd-4Y-xZn-0.6Zr (x = 0, 1, 2 wt%) alloys has been optimized based on thermodynamic calculations and experiments. The phase transformations during the heat treatment and their effect on the mechanical properties of the alloys were discussed. Using thermodynamic calculations, three solution treatment temperatures of 475 °C, 500 °C, and 525 °C were determined, and the phase transformation under these temperatures were calculated and characterized, the results aligned well with experimental results. The optimal solution treatment technology was determined to be 500 °C for 18 h. After solution treatment, experimental alloys were subject to isothermal aging at 225 °C, the peak aging time for the experimental alloys was established. The microstructure under peak-aged state of the alloy was characterized, revealing a co-existed β’ and β1 phases. The GWZ1041K alloy, after peak aging treatment, exhibited optimal mechanical properties, with a tensile strength, yield strength, and elongation of 392.3 MPa, 249.3 MPa, and 5.7%, respectively. The study further analyzed the reasons for the microstructure transformation during the heat treatment and their influence on mechanical properties. •Optimization of Mg10Gd-4Y-xZn-0.6Zr alloys' heat treatment using thermodynamic calculations and experiments.•Discussion on phase transformations during heat treatment and their impact on mechanical properties.•Determination of optimal solution treatment, establishment of peak aging time, and characterization of microstructure.