摘要
采用累积叠轧工艺对AZ31镁合金薄板进行剧塑性变形,研究了累积叠轧变形过程中镁合金板材的组织及性能演变。实验结果表明,累积叠轧可以有效细化AZ31镁合金板材的晶粒组织,显著改善室温延伸率,是制备大尺寸、高性能细晶镁合金板材的一种有效、经济而且可以实现工业化生产的技术。累积叠轧5道次后AZ31镁合金板材组织均匀,晶粒尺寸为1-2μm左右,晶粒细化源于大的累积变形及表面剪切变形;室温抗拉强度和延伸率可达到349MPa和22.46%,可归因于晶粒细化对镁合金强度和塑性的改善。累积叠轧板材的道次间的加热使ARB组织粗化,减小了累积叠轧过程中晶粒持续细化的效果。
Accumulative roll-bonding was performed on AZ31 magnesium alloys. The evolution of microstructure and mechanical properties of AZ31 sheets during accumulative roll-bonding was researched. The results show that accumulative roll-bonding provides a simple, effective and inexpensive technology to prepare large-sized AZ31 Mg alloy sheets with fine grains and improved ductility at ambient temperature. AZ31 sheets with fine grains about 1-2μm was successfully achieved by accumu-lative roll-bonding after 5 cycles. The grain refinement during ARB can be owing to the severe accumulated strain and shear strain in the surface of the sheets. The best compromise between strength and ductility of ARBed AZ31 sheets is obtained after 5 cycles. In this case, the average ultimate ten-sile stress is 349MPa and average tensile elongation is 22.46%. The strengthening and ductility increasing can be attributed to the occurrence of significant grain refinement. However, grain growth occurs easily by reheating between ARB cycles, which will partly cancel out the grain refinement cau- sing by accumulated strain.
出处
《材料工程》
EI
CAS
CSCD
北大核心
2008年第3期22-27,共6页
Journal of Materials Engineering
基金
中国博士后科学基金资助项目(20060400748)
华南理工大学金属新材料制备与成形广东省重点实验室开放基金资助项目(2007001)
关键词
累积叠轧
镁合金
组织
性能
accumulative roll-bonding
magnesium alloy
microstructure
mechanical property
