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利用表面机械研磨(SMAT)技术在纯铜表面制备出梯度结构(GS)层,并且通过改变表面机械研磨的试验温度,研究不同变形温度对纯铜组织及力学性能的影响。利用显微硬度计、拉伸试验机、光学显微镜等仪器对液氮下表面机械研磨(LN-SMAT)样品和室温下表面机械研磨(R-SMAT)样品的组织及力学性能进行测试分析。结果表明,LN-SMAT样品的表面硬度及屈服强度更高、梯度结构层厚度更厚,且两种样品的均匀伸长率基本相同,说明低温下表面机械研磨的强化效果更为明显;LN-SMAT样品存在大量孪晶,R-SMAT样品的制备过程可能发生动态回复及动态再结晶。
Gradient structure (GS) layer was prepared on the surface of pure copper by surface mechanical milling (SMAT) technique. The influence of different deformation temperature on microstructure and mechanical properties of pure copper was studied by changing the test temperature of surface mechanical grinding. The microstructure and mechanical properties of LN-SMAT samples and R-SMAT samples at room temperature were tested by microhardness tester, tensile tester and optical microscope. The results show that the surface hardness and yield strength of LN-SMAT sample are higher, the thickness of gradient structure layer is thicker, and the uniform elongation of both samples are basically the same, which shows that the strengthening effect of surface mechanical grinding is more obvious at low temperature. LN- There are a large number of twins in the SMAT sample, and the dynamic recovery and dynamic recrystallization may occur in the preparation of the R-SMAT sample.