Microstructure, Mechanical Properties and Fire Resistance of High Strength Mg-Gd-Y-Zr Alloys

• Published in: Metals (Basel ) Vol. 12; no. 9; p. 1456
• Main Authors: Qian, Yafeng, Zhao, Yanhui, Dong, Xiaorui, Yu, Wei, Feng, Jianhang, Yu, Hui
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.09.2022
• Subjects: Aging; Aging (metallurgy); Aircraft; Alloying effects; Alloys; Aluminum alloys; Elongation; extrusion; Extrusion dies; Fire resistance; Flame retardants; Flammability; Gadolinium; Heat; High strength alloys; High temperature; Magnesium alloys; Mechanical properties; Mg-Gd-Y-Zr alloy; Microstructure; non-flammability; Solid solutions; Specialty metals industry; Tensile strength; Titanium alloys; Weight reduction; Yield stress; Zirconium; China
• ISSN: 2075-4701; 2075-4701
• DOI: 10.3390/met12091456

With the lightest green structural material for 21st century, a significant weight reduction effect was expected to solve the lightweight problem in aerospace and other fields. However, the material’s poor mechanical properties and flammability limited its widely application in such fields. In this paper, the GWK series alloys (Mg-5.3Gd-4.11Y-0.13Zr, Mg-5.5Gd-4.22Y-0.19Zr, and Mg-5.46Gd-4.02Y-0.20Zr, in wt.%) were designed, and we explored the effect of alloy composition and process on the microstructure and properties of GWK series alloys subject to casting, homogenization, extrusion, ageing and ignition. The result show that Mg-5.3Gd-4.11Y-0.13Zr alloy after T4 treatment at 500 °C/6 h obtains an excellent solid solution effect. In addition, the aged alloy shows a good balance of mechanical properties, a tensile strength of 405 MPa, yield strength of 275 MPa, as well as elongation of 8.12%, and excellent non-flammability.