摘要
研究了Mg-4Zn-0.5Er-1Y变形合金轧制板材在经200～380℃,保温0.5～4h退火处理后,合金显微组织的演变及其力学性能的变化规律。结果表明,该合金退火后均出现明显的动态再结晶组织,且晶粒比较细小,基体中存在大量含有稀土元素的第二相,这些第二相在热轧状态下破碎成细小的颗粒,促进了动态再结晶晶粒的异质形核。合金退火处理后的强度较原轧制态降低,但塑性却得到明显的改善。最佳退火温度为350℃,保温0.5h后晶粒尺寸约为8μm,抗拉强度为276MPa,伸长率达到最大为22.5%。经过计算可知,该合金再结晶晶界迁移激活能为22.76kJ/mol,同时建立了该合金再结晶晶粒长大的动力学模型。
Microstructure evolution and mechanical properties of rolled Mg-4Zn-0.5Er-1Y alloy sheets with annealing at 200~380℃ for 0.5~4 h were investigated. It is found that distinct dynamic recrystallization grain with fine size can be observed in the annealed alloy sheets. Amounts of secondary phase containing RE exist in the matrix alloy, which are broken into fine particle after hot rolling to promote the heterogeneous nucleation of dynamic recrystallization grain. Strength of the alloy sheet after annealing treatment is decreased with the obvious improvement of plasticity. The alloy sheet with approximately 8 μm in size exhibits desirable mechanical properties with annealing at 350℃ for half hour, such as tensile strength of 276MPa and elongation of 22.5%. Activation energy of grain boundary migration reaches 22.76kJ/mol. In addition, kinetics model of dynamic recrystallization grain growth was established.
出处
《特种铸造及有色合金》
CAS
CSCD
北大核心
2010年第12期1086-1089,共4页
Special Casting & Nonferrous Alloys
基金
辽宁省教育厅高校科研项目(2008329),辽宁省教育厅材料成型与组织性能控制重点实验室开放式基金项目(200909)
鞍山市科技局项目(2008SF54)
辽宁科技大学大学生科研训练计划项目(2010年第6期)
关键词
热处理
力学性能
动态再结晶
Heat Treatment, Mechanical Properties, DRX
