AM80-xSr-yCa镁合金高温压缩变形行为

采用Gleeble-1500热模拟实验机对一种新型AM80-xSr-yCa镁合金进行高温压缩变形实验,研究其在温度300℃~450℃、应变速率0.01s-1~10s-1条件下的流变行为。高应变速率下,试样的变形热带来的温升不可忽略,对真应力-真应变的测量值进行相应修正后,求得了本构方程中的系列常量。结果表明,应变速率和变形温度的变化,强烈影响着合金流变应力的大小,流变应力值随变形温度的降低和应变速率的提高而增大;金相组织观察表明,动态再结晶是该实验条件下晶粒细化和材料软化的主要机制,再结晶的程度主要受变形参数影响。变形温度越高,变形量越大,动态再结晶进行的越充分;应变速率越大,再结晶平均晶粒尺寸就越小。

The study on the hot compression deformation behavior of AM80-xSr-yCa alloy

Hot compression tests of a new type AM80-xSr-yCa magnesium alloy were performed on Gleeble-1500 at strain rates 0.01s-1~10s-1 and deformation temperature 300℃~450℃.The true stress/true strain curves were obtained in the tests.The experiment data of the flow stress was corrected due to the deformation heat induced at high strain rate and the constitutive constants were calculated based on the corrected flow stress.The flow behavior of this alloy at high temperature was studied.The results show that the relation between stress and strain is obviously influenced by strain rate and deformation temperature,the flow stress increases with the increase of strain rate and decreases with the increase of deformation temperature.The optical microstructure observation shows that the dynamic recrystallization is the main mechanism for grain refinement and material softening under the test conditions and this mechanism is influenced by deformation parameters.The recrystallized grain size increases with the increase of deformation temperature and decreases with the.increase of strain rate.