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对比研究了高温轧制制备的Mg-1.02Zn及Mg-0.76Y(质量分数,%)合金在不同温度退火条件下的组织演变及静态再结晶和晶粒长大动力学行为.结果表明,Mg-1Zn合金的轧制组织以剪切带和孪晶为主,在剪切带和孪晶内伴随着动态再结晶;而Mg-1Y合金的轧制组织中只有孪晶,未观察到剪切带和再结晶发生.退火过程中,Mg-1Zn合金静态再结晶过程主要受控于形核过程,而Mg-1Y合金则既受控于形核过程又受控于长大过程.利用经典的JMAK模型和长大模型分别描述了2种合金热轧制后的静态再结晶和晶粒长大动力学过程,结果表明,静态再结晶过程的Avrami因子n值与理想预测值偏离可能来自于再结晶的不均匀形核.固溶稀土Y原子比Zn原子对晶界移动的拖曳作用更强,导致Mg-1Y合金比Mg-1Zn合金晶粒长大因子n’更高.
The microstructure evolution, static recrystallization and grain growth kinetics of Mg-1.02Zn and Mg-0.76Y (mass fraction,%) alloys prepared by high-temperature rolling at different annealing temperatures were compared.The results show that Mg The microstructure of -1Zn alloy is dominated by shear banding and twins, accompanied by dynamic recrystallization in the shear zone and twins. In the microstructure of Mg-1Y alloy, there is only twins and no shear is observed Banding and recrystallization occurred during the annealing process, the static recrystallization process of Mg-1Zn alloy was mainly controlled by the nucleation process, while the Mg-1Y alloy was controlled by both the nucleation and growth process. JMAK model and growth model describe the static recrystallization and grain growth kinetics of the two alloys after hot rolling. The results show that the Avrami factor n in the static recrystallization may deviate from the ideal predicted value Crystallization of heterogeneous nucleation.Reducing effect of solid solution rare earth Y atom on the movement of the grain boundary is stronger than that of Zn atom, resulting in higher grain growth factor n ’of the Mg-1Y alloy than that of the Mg-1Zn alloy.