New Method for Improving Formability of AZ31B Magnesium Alloy Sheets

摘要

The magnesium alloy sheets have poor plasticity and formability due to their strong (0002) basal texture. In this paper a new method, repeatedly unidirectional bending (RUB), was used to improve formability of the magnesium alloy sheets. The samples were deformed repeatedly by the unidirectional bending at room temperature and annealed. Firstly, RUB route which is the most infection to formability was investigated. There were two RUB route, single surface RUB and reserve surface RUB. The result showed that better formability can be obtained by the reserve surface RUB. Focused on the development of formability of magnesium alloy sheet, the technological parameters, such as RUB passes, radius of support, annealing temperature and holding time, were determined by orthogonal experiment,and hence the optimal RUB process was acquired. Mechanical property of the samples before and after RUB were characterized and compared. After RUB, (0002) basal textural component of cold rolled magnesium alloy sheet was weakened and σ_b, σ_(0.2) decreased obviously. The Erichsen values can be considerably enhanced from 3.53mm to around 6.0mm through RUB.