Effects of ECAP Processing Temperature and Number of Passes on the Mechanical Behavior of CuAg0.1 Alloy

This study investigates the effect of equal channel angular pressing (ECAP) temperature and pass number on the microstructural evolution and hardness response of a CuAg0.1 alloy. ECAP was performed by using route Bc at room temperature and 100 °C for up to six passes. X-ray diffraction results showed that no additional crystalline phase was detected after ECAP, while peak broadening and relative intensity changes indicated deformation-induced lattice distortion, defect accumulation, and a tendency toward preferred orientation. Optical microscopy revealed progressive microstructural subdivision with increasing pass number, particularly under room-temperature processing. Vickers microhardness increased sharply after the first ECAP pass and approached a saturation-like regime after approximately four passes. Room-temperature ECAP produced higher hardness and hardness-derived estimated strength values than processing at 100 °C, indicating more effective defect storage and suppressed recovery. In contrast, the lower hardening response at 100 °C is attributed mainly to thermally assisted recovery and dislocation rearrangement. The section-dependent hardness response suggests ECAP-induced anisotropy was associated with the imposed shear deformation and preferred crystallographic orientation. Within the investigated processing, four-pass room-temperature ECAP provided the most effective hardness-based strengthening response.