Characterization of mechanical property of magnesium AZ31 alloy sheets for warm temperature forming

• Published in: International journal of mechanical sciences Vol. 93; pp. 204 - 217
• Main Authors: Koh, Youngwoo, Kim, Daeyong, Seok, Dong-Yoon, Bak, Jeonghwan, Kim, Sang-Woo, Lee, Young-Seon, Chung, Kwansoo
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.2015
• Subjects: Failure; Forming; Hardening; Hardening deterioration (softening); Inverse calibration method; Magnesium; Magnesium AZ31 alloy sheet; Magnesium base alloys; Mathematical models; Mechanical properties; Strain localization; Warm forming process; Magnesium AZ31 alloy sheet; Inverse calibration method; Warm forming process; Hardening deterioration (softening)
• ISSN: 0020-7403; 1879-2162
• DOI: 10.1016/j.ijmecsci.2015.02.001

A method based on the numerical inverse approach to characterize the mechanical property of the Magnesium AZ31 alloy sheet for warm temperature forming was discussed in this work. In particular, temperature-dependent hardening and strain rate sensitivity were characterized based on uniaxial tensile test data measured at between 100°C and 300°C with the interval of 50°C. Hardening deterioration associated with micro-void development as well as dynamic recovery and dynamic re-crystallization, observed beyond the uniform deformation limit, was also accounted for. Importance of the proper characterization of the hardening deterioration was confirmed by validating the failure by strain localization in the circular cup drawing test under the warm forming condition. With mechanical behavior properly described, failure with strain localization was predictable without referring to forming limit diagram but directly evaluating strain localization for material elements in this work. Uniaxial compression tests were also performed at various temperatures below 200°C to assess asymmetric behavior in tension and compression. •The mechanical property of the AZ31 Mg alloy sheet was characterized at warm temperatures.•The mechanical property with softening properly predicted failure by strain localization.•Failure was predictable directly evaluating strain localization for material elements.