Homogenization heat treatment of Mg–7.0 wt%Y–1.0 wt%Nd–0.5 wt%Zr alloy

• Published in: Rare metals 2020-10, Vol.39 (10), p.1196-1201
• Main Authors: Liu, Jing-Bao, Zhang, Kui, Han, Jing-Tao, Li, Xing-Gang, Li, Yong-Jun, Ma, Ming-Long, Yuan, Jia-Wei, Li, Meng
• Format: Article
• Language: English
• Subjects: Biomaterials; Casting alloys; Chemistry and Materials Science; Elongation; Energy; Hardness measurement; Heat treatment; Homogenization; Intermetallic compounds; Magnesium base alloys; Materials Engineering; Materials Science; Mechanical properties; Metallic Materials; Microscopy; Nanoscale Science and Technology; Optical microscopy; Phases; Physical Chemistry; Tensile strength; Yttrium; Zirconium base alloys
• ISSN: 1001-0521; 1867-7185
• DOI: 10.1007/s12598-015-0588-0

The microstructures and mechanical properties of Mg–7.0 wt%Y–1.0 wt%Nd–0.5 wt%Zr magnesium alloy were investigated both in as-cast condition and after homogenization heat treatment by differential scanning calorimetry (DSC), optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM) and hardness measurement. The results indicate that the as-cast alloy consists of α-Mg matrix, Mg 24 Y 5 and Mg 41 Nd 5 phases, which are eutectic phases (cubic Y-rich phase). With the increase in homogenization temperature and time, the Mg 24 Y 5 and Mg 41 Nd 5 phases are completely dissolved into matrix, and only yttrium of intermetallic compounds leaves around boundary. After homogenization heat treatment, the elements distributed uniformly and the grains grow up not obviously, only yttrium element of intermetallic compounds left around boundary. The optimum homogenization condition is at 537 °C for 16 h. The mechanical properties are improved after homogenization, with tensile strength of σ b  = 181 MPa, yielding strength of σ 0.2  = 144 MPa and elongation of δ  = 5.5 %, which are better than those of as-cast alloy.