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利用两种等通道角挤压(ECAP)方法(普通单步ECAP和两步ECAP)制备细晶ZK60合金。采用金相显微镜、扫描电镜、透射电镜和X射线衍射仪对合金的组织和织构进行观察,通过拉伸试验研究不同ECAP方法对合金力学性能的影响。结果表明:与单步ECAP变形相比,两步ECAP变形,由于降低了变形温度,晶粒细化效果更好;经过(240℃,4道次)+(180℃,4道次)两步ECAP变形后,合金晶粒细化至约0.8μm;合金的力学性能与材料的织构密切相关,由于存在织构软化效应,与挤压态相比,经单步ECAP变形后合金的强度有所降低,而伸长率明显提高;但经两步ECAP变形后,由于细晶强化和亚结构强化的作用,合金的强度得到提高。
Fine grain ZK60 alloys were prepared using two equal channel angular pressing (ECAP) methods (plain single-step ECAP and two-step ECAP). The microstructure and texture of the alloy were observed by optical microscopy, scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The tensile tests were conducted to study the effects of different ECAP methods on the mechanical properties of the alloy. The results show that compared with single-stage ECAP deformation, the two-step ECAP deformation is better than the one-step ECAP deformation due to the decrease of deformation temperature. After 240 ℃, 4 passes + 180 ℃, 4 passes, ECAP deformation, the alloy grain refinement to about 0.8μm; mechanical properties and texture of the material is closely related to the fabric softening effect, compared with the extruded state, single step ECAP alloy strength after deformation , But the elongation increased obviously. However, after two-step ECAP deformation, the strength of the alloy was improved due to the effect of fine grain strengthening and substructure strengthening.