Home > Research > Publications & Outputs > Effect of grain size on mechanical characterist...

Electronic data

  • Manuscript-SWT

    Accepted author manuscript, 5.15 MB, PDF document

    Available under license: CC BY: Creative Commons Attribution 4.0 International License

Links

Text available via DOI:

View graph of relations

Effect of grain size on mechanical characteristics and work-hardening behavior of fine-grained Mg-0.8Mn alloy via adjusting extrusion temperature

Research output: Contribution to Journal/MagazineJournal articlepeer-review

Published
  • C.C. Li
  • X.G. Qiao
  • W.T. Sun
  • I.S. Golovin
  • H.S. Kim
  • T. Sakai
  • M.Y. Zheng
Close
Article number177322
<mark>Journal publication date</mark>5/01/2025
<mark>Journal</mark>Journal of Alloys and Compounds
Volume1010
Publication StatusPublished
Early online date1/11/24
<mark>Original language</mark>English

Abstract

In this study, the Mg-0.8Mn (M08, wt%) alloy is subjected to hot extrusion at various temperatures ranging from 150 ℃ to 300 ℃, and the correlations between the microstructure evolution, tensile properties, and work hardening behavior at ambient temperature are elaborated. The M08 alloy extruded at 150 ℃ exhibits a bimodal microstructure, which included undynamic recrystallized (unDRXed) grains and fine dynamic recrystallized (DRXed) grains with an average size of 1.4 μm. As the extrusion temperature exceeds 210 °C, fully DRXed grains can be observed with grains growth becoming more pronounced with the increase of extrusion temperature. Notably, Mn atomic segregations are evident at the grain boundaries (GBs) in the M08 alloy extruded at 150 °C. It is also essential to highlight that the propensity for GB segregation is diminished with higher extrusion temperature, and the amount of α-Mn precipitates within grain interiors is increased in the M08 sample extruded at 300 ℃. An intriguing observation is the abnormal rise in yield strength (YS) with grain size as the extrusion temperature is increased. This phenomenon can be attributed to the diminishing effect of GB sliding and the concurrent enhancement of GB strengthening effect. However, as the extrusion temperature is raised from 150 °C to 300 °C, the ductility of M08 alloy experiences a substantial decline from 74 % ± 4–16 % ± 3 %. Meanwhile, the grain growth can bring about an increased strain hardening rate, which is primarily dependent on the transition in the dominant deformation mechanism from grain boundary sliding (GBS) to dislocation slip. This transition leads to a more substantial accumulation of dislocations within the coarser grains, thereby affecting the mechanical behavior of M08 alloy. This work provides valuable insights into the influence of extrusion temperature on the microstructure evolution and mechanical properties of Mg-0.8Mn alloy, offering a foundation for optimizing the processing parameters to achieve desired mechanical performance.