摘要
目的探索工艺参数对微观组织和力学性能的影响。方法材料选用铸态ZK60合金,通过试验研究挤压比、往复挤压道次对镁合金微观组织演变的影响,分析挤压比对T6处理的材料力学性能的影响。结果在一定范围内增大挤压比和增加往复挤压道次均有助于组织细化。在350℃、挤压比为8时,经过8道次往复挤压变形可以细化晶粒到3μm左右。晶粒尺寸达到5μm以下,增加往复道次使晶粒细化的效果不明显,但有利于晶粒的均匀化。在往复挤压温度350℃,挤压比8,往复道次8的条件下,经过T6处理的试样具有良好的综合力学性能,伸长率达到22.1%,抗拉强度为308.6 MPa。结论 ZK60镁合金在往复挤压和动态再结晶过程中,晶粒的细化与往复挤压道次和挤压比有关。若挤压比较小,尽管往复道次较大,但是晶粒细化的效果不明显;合理的匹配挤压比与往复道次,能获得细小、均匀的组织。
The paper aims to investigate effects of process parameters on microstructure and mechanical properties of as-cast ZK60 alloy. As-cast ZK60 alloy was selected to test and observe influences of cyclic extrusion and compression on mi- crostructure of magnesium alloy and effects of extrusion ratio on mechanical properties of material subjected to T6 treatment. Increasing the extrusion ratio and CEC pass to a certain extend could contribute to the refinement of the microstructure. In CEC process for 8 passes at 350 ℃ with extrusion ratio of 8, the grain could be refined to about 3 μm. The refining effect of grain size was not obvious with the increase of CEC pass when the grain size is below 5 μm, but it was beneficial to the uniformity of grain. The sample processed by CEC for 8 passes at 350 ℃ with extrusion ratio of 8 after T6 treatment had good comprehensive mechanical property. The corresponding elongation reached 22.1% and the tensile strength reached 308.6 MPa. In the process of CEC and dynamic recrystallization, grain refinement of ZK60 magnesium alloy is related to the CEC pass and extrusion ratio. If extrusion ratio is relatively small, even if the CEC pass is large, the effect of grain refinement is not obvious. Reasonable matching extrusion ratio and CEC pass can obtain refined and uniform microstructure.
出处
《精密成形工程》
2017年第2期40-44,共5页
Journal of Netshape Forming Engineering
关键词
往复挤压
ZK60镁合金
微观组织
力学性能
cyclic extrusion and compression
ZK60 magnesium alloy
microstructure
mechanical property
作者简介
韩飞（1962-），男，硕士，副教授，主要从事锻压技术的科研与教学工作。
