摘要
采用等通道转角挤压变形工艺,在573 K下以Bc路径对Mg-6Zn-2Si镁合金进行4道次和8道次挤压细化合金晶粒来提高其力学性能,同时对合金室温拉伸断口进行分析,并阐述了等通道挤压改善实验合金微观组织和力学性能的机理。结果表明:经4道次挤压后晶粒由310μm细化到13μm,Mg_2Si相最大约60μm,细化为细小颗粒状约7μm,α-Mg基体与Mg Zn相均得到显著细化,屈服强度提高180%,伸长率提高140%,抗拉强度提高75%。与4道次相比,经8道次挤压后微观组织无明显变化,屈服强度有所提高,抗拉强度和伸长率变化不大。合金的室温拉伸断口由铸态合金的脆性断口过渡为韧性断口,并且韧窝加深,分布更均匀。
The mechanical properties of Mg-6Zn-2Si alloy were improved by 4 gates and 8 gates equal-channel angular pressing at 573 K with the Bc path, at the same time the tensile fracture at room temperature was analyzed, and the improving mechanism of equal-channel angular pressing on microstructure and properties were explored. The results show that the grain refines from 310 μm to 13 μm after 4 gates extrusion, the maximum size of Mg_2 Si phase is about 60 μm, the size is 7 μm after refining. α-Mg matrix and Mg Zn phase are refined significantly. Yield strength is increased by 180%,elongation is increased by 140%, tensile strength is increased by 75%. Compared with 4 gates, the microstructure after 8gates extrusion has no obvious change, yield strength has increased, tensile strength and elongation has a little change. The tensile fracture of the alloys at room temperature transforms to the ductile fracture from brittle fracture of the as-cast alloy,and the toughening dimple become deep, more uniform in distribution.
出处
《铸造技术》
CAS
北大核心
2016年第5期988-991,共4页
Foundry Technology
基金
西京学院科研基金资助项目(XJ130240)
