Effects of single-pass large-strain rolling on microstructure and mechanical properties of Mg-Al-Ca alloy sheet

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 786; p. 139332
• Main Authors: Cheng, Renshan, Li, Man, Du, Sen, Pan, Hucheng, Liu, Yujie, Gao, Meiqi, Zhang, Xingshuo, Huang, Qiuyan, Yang, Changlin, Ma, Lifeng, Qin, Gaowu
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.06.2020; Elsevier BV
• Subjects: Dynamic recrystallization; Elongation; Extrusion; Grain refinement; Grain size; High strength alloys; Magnesium alloy; Magnesium base alloys; Mechanical properties; Metal sheets; Microstructure; Recrystallization; Rolling deformation; Second phase; Strain; Ultimate tensile strength; Second phase; Rolling deformation; Dynamic recrystallization; Grain refinement; Magnesium alloy
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2020.139332

A new wrought magnesium alloy sheet, the Mg-1.8Al-1.8Ca wt.% alloy, with high strength and good ductility has been fabricated by the one-step extrusion and subsequent single-pass large-strain rolling process. The microstructure analysis shows that a large amount of un-dynamically recrystallized (un-DRXed) regions exist in the as-extruded alloy. After the large-strain rolling process, the grain size of the sheet is refined and the microstructure becomes more uniform, as compared with the as-extruded counterpart. The average grain size of Mg-1.8Al-1.8Ca alloy is refined from the ~ 2.42 μm in the as-extruded state, to be ~ 1.68 μm and ~ 1.42 μm, after rolling at 350 °C and 300 °C, respectively. The wrought Mg-1.8Al-1.8Ca alloy sheet, which was rolled at 300 °C by one-pass thickness reduction of ~ 78%, exhibits the highest absolute strengths with yield strength of ~ 298 MPa and ultimate tensile strength of ~ 319 MPa, and the moderate elongation to failure of ~ 6% is also obtained.