| Magnesium alloy plastic deformation ability is poor and slip systems are lessbecause of its hexagon close-packed crystalline structure. So to improve the plasticityof magnesium alloy, it is necessary to deeply study the mechanism of plasticdeformation of magnesium alloy.work-hardening is the basic problem of plasticdeformation of Magnesium alloy.This paper systematically studied the work-hardeninglaw and the causes of work-hardening. The stress-strain curves and the work-hardeningrate curves of AZ31magnesium alloy have been studied through tensile andcompression tests. Measuring the texture of magnesium alloy before and afterdeformation, which indicates that as-extruded magnesium alloy has typical basaltexture.The basal plane rotates and generates1012tensile twins when compressalong the direction of as-extruded.This explains the phenomenon about mechanicalanisotropy of magnesium alloys in different direction. This paper mainly studied theconditions and mechanism of stage Ⅱ work hardening,results show that:it is easy toappear the stage Ⅱ work-hardening under the low temperature and high strain ratedeformation,meanwhile deeply analyzing the cause of stageⅡwork-hardeningaccording to the flow stress and dislocation mode. This paper deeply studied the stageⅢ work hardening law of AZ31magnesium alloy, the results show that:the stage Ⅲwork hardening conforms to Voce law, namely work-hardening rate has a linearrelation with the stress, the concrete equation of Voce law is determined according tothe experimental results. |
PDF Full Text Request