对ZK60镁合金进行了平面应变等温压缩试验,并对不同变形条件下压缩试样的微观组织、拉伸性能进行分析。结果表明,ZK60合金热变形后力学性能得到提高,尤其是塑性得到较大改善,伸长率最高达到38%,断口形貌由河流状变为韧窝状,这主要是由于变形过程中产生动态再结晶,使晶粒明显细化;均匀态组织中个别未溶的共晶组织呈点状断续分布于晶界上,这些点状裂纹在变形过程中不易扩展还可能愈合;在300-380℃对均匀态ZK60合金进行平面压缩后。可获得较优的综合力学性能。
ZK60 alloys were compressed in plane strain and the microstmcture and tensile properties of alloys under different compression state were investigated. The results show that the mechanical properties, especially the plasticity of ZK60 alloy is improved after hot deformation, the highest elongation percentage is up to 38% and the tensile frac~tre morphology changes from river to dimple. This is mainly caused by DRX during compression, leading the refinement of grains; the other reason is that the punctate cracks can tend to heal itself rather than extend during the compression, because there are some punctate unsoluted eutectic phases distributing along the grain boundaries discontinuously after homogenization. In these tests, the mechanical properties of the alloy compressed at 300-380 ℃ are optimal.