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通过高压扭转(HPT)技术在不同转速条件下实现了Cu试样的晶粒细化。利用光学显微镜(OM)、透射电镜(TEM)及显微硬度计观察并测试了组织的结构与性能,并基于有限元计算了变形诱导试样的温升,研究了转速对Cu试样的组织细化与性能的影响。结果表明:转速由1/3r.min-1增大至1r.min-1,经1圈扭转变形,试样温度由40.8℃升高到54.1℃,变形组织均为100～600nm的高位错密度位错胞/亚晶组织,显微硬度由初始态的52HV0.05增大至140HV0.05;经16圈扭转变形,试样温度由50.4℃升高到97.4℃,组织细化到200nm。慢速扭转变形试样晶内位错密度高,微观组织处于严重变形状态;而快速扭转试样晶内衬度均匀,位错较少,微观组织经历明显的动态回复,显微硬度较慢速扭转变形试样低6%。
The grain refinement of Cu samples was achieved by HPT at different rotation speeds. The microstructures and properties of the samples were observed and measured by optical microscope (OM), transmission electron microscope (TEM) and microhardness tester. The temperature rise of deformation induced samples was calculated based on finite element method. The effects of rotational speed on the microstructure of Cu samples Refinement and performance impact. The results show that the rotating speed increases from 1 / 3r.min-1 to 1r.min-1, and after 1 cycle of torsional deformation, the temperature of the sample increases from 40.8 ℃ to 54.1 ℃, and the deformed structure has a high dislocation density of 100-600nm The dislocation cells / subgrain microstructure increased from 52HV0.05 to 140HV0.05 in the initial state. After 16 cycles of torsional deformation, the sample temperature increased from 50.4 ℃ to 97.4 ℃, and the microstructure was refined to 200nm. The samples with slow torsional deformation had high intragranular dislocation density and microstructure was in severe deformation state. However, the samples with rapid torsional deformation showed uniform grain size and few dislocations, and the microstructure experienced significant dynamic recovery with a slower microhardness Torsion deformation of the sample is 6% lower.