Abstract:  In order to further investigate the preparation and property of ultra-grained magnesium alloy‚AZ31magnesium alloy was prepared by means of equa- l channel angular pressing （ECAP） and B c route in the die with the intersecting angle φ＝120°．The microstructure and property of the processed material with different passes were then analyzed and tested．The results indicate that‚with the increase in the pressing pass‚the grains become finer and finer and the tensile behavior changes remarkably‚that with 12 pressing passes‚the total deformation strain of the alloy is about 8 and the grains are effectively refined to a mean size of 1～5μm‚and that the tensile strength of the alloy changes little‚while the yield strength decreases to about100MPa‚and the ductility increases to more than45％．

Key words:  equal channel angular pressing, magnesium alloy, microstructure, property