An in-depth evaluation on the influences of elevated temperature ECAP on mechanical properties and corrosion behavior of copper metal

The need for large amounts of force in the equal channel angular pressing (ECAP) process has always caused problems and limitations in conducting it. In the current study, elevated temperature ECAP process is proposed as an approach to reduce force and its effects on the microstructural and mechanical properties of copper metal has been investigated, comprehensively. The research results showed that due to the phenomenon of recrystallization and the creation of refined and equiaxed grains, the microstructure of copper and its resistance to corrosion was improved. Accordingly, the stress concentration created in the triple points was decreased and, consequently, the fracture toughness of the material increased. Based on the present findings, the crack growth becomes intergranular, so the crack growth path becomes longer. Moreover, only one component of the applied force causes the crack to grow, as a result, the resistance of the material increases. Therefore, for example, the fatigue crack growth range threshold of the material subjected to the ECAP process was 3.5 times larger than those of the base metal (BM). Also, it can increase ultimate strength up to 65.4%, hardness up to 89% and impact toughness up to 91.9%. In addition, it was found that if the ECAP process is performed at elevated temperatures, the maximum required force can be reduced by 45.6%.