The microstructural and strengthening behavior of two CuMg alloys, with 0.2 and 0.5 m.-% of Mg, were analyzed after severe plastic deformation by Equal Channel Angular Pressing (ECAP). Both alloys were passed through a 90° inner angle ECAP die at room temperature up to 16 passes following route Bc. The EBSD analysis of the deformed microstructure revealed a significant grain refinement after the 2nd pass. Average grain sizes as fine as 0.31 and 0.24 µm for the CuMg0.2 and CuMg0.5, respectively, were obtained after 16 passes. The tensile strength of the ECAPed samples of the present CuMg alloys did not reach a saturation level, attaining 570 and 750 MPa after 16 passes for the CuMg0.2 and CuMg0.5, respectively. The dependence of the yield stress on deformation (i.e. number of ECAP passes) and Mg content was evaluated in terms of the Hall–Petch effect (influence of grain size), dislocation density (through the subgrain hardening effect) and solid solution strengthening. Results indicated that the stronger effect comes from the subgrain microstructure rather than from High Angle Grain Boundaries (HAGB). A minor effect of the chemical composition was also noticed.
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机译：通过等通道转角挤压（ECAP）对发生严重塑性变形后的Mg分别为0.2和0.5 m .-％的两种CuMg合金的显微组织和强化行为进行了分析。两种合金均在室温下通过90°内角ECAP模头，遵循路径Bc最多进行16次通过。变形后的微观结构的EBSD分析显示，第二遍通过后，晶粒明显细化。经过16次通过后，CuMg0.2和CuMg0.5的平均晶粒尺寸分别为0.31和0.24 µm。目前的CuMg合金的ECAPed样品的抗拉强度未达到饱和水平，CuMg0.2和CuMg0.5分别经过16次合格后分别达到570和750 MPa。屈服应力对变形（即ECAP道次）和Mg含量的依赖性通过Hall-Petch效应（晶粒尺寸的影响），位错密度（通过亚晶粒硬化效应）和固溶强化来评估。结果表明，更强的作用来自亚晶粒的微观结构，而不是来自高角度晶粒边界（HAGB）。还注意到化学成分的轻微影响。
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