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利用显微硬度计和电子拉伸机,研究了等径弯曲通道变形(Equal Channel Angular Pressing-ECAP)前后纯铜的硬度、力学性能,分析了ECAP制备超细晶铜(UFG)的强化机制。结果表明,纯铜在ECAP变形中出现了加工硬化-软化的饱和现象,即流动应力随变形量增加先迅速增大,在8道次达到最大(σb=410MPa),而后趋于饱和。强度可达400～410MPa,伸长率为12%～20%,硬度(HV)为140～146。利用MA模型合理解释了ECAP制备超细晶材料的拉伸力学行为。
The hardness and mechanical properties of pure copper before and after Equal Channel Angular Pressing-ECAP (ECAP) were studied by using microhardness tester and electronic stretcher. The strengthening mechanism of ECF for preparing ultrafine copper (UFG) was analyzed. The results show that the pure copper softens during the deformation of ECAP. The flow stress increases rapidly with the increase of deformation, reaches the maximum at 8 passes (σb = 410 MPa), and then tends to be saturated. Strength up to 400 ~ 410MPa, elongation of 12% to 20%, hardness (HV) of 140 to 146. The MA model was used to reasonably explain the tensile behavior of ECAP prepared ultrafine-grained materials.