Effect of Route BC Equal-Channel Angular Pressing on the Microstructure, Microtexture, and Homogeneity of Al-18%Si-4.5%Cu Alloy

Abstract

Al-18%Si-4.5%Cu alloy was processed by route BC equal-channel angular pressing (ECAP) at a temperature of 400 °C. Electron backscattered diffraction (EBSD) was used to analyze the microstructure and microtexture during the ECAP process. The microstructural results showed three important effects: First, the particle-stimulated nucleation (PSN) and continuous dynamic recrystallization (CDRX) had the main effect on the refinement of the aluminum matrix during the ECAP process. Second, after the third and fourth passes, due to redundant strain created by route BC, the heterogeneous microstructure was observed. Third, further ECAP passes led to further fragmenting and better distribution of the particles. The microtextural results showed that further ECAP passes led to strengthening the $$B/\overline{B}$$ component at the center and also strengthening the A*1 and A*2 components at the bottom of specimens. The microhardness results showed that the grain refinement strengthening and precipitation strengthening were the main strengthening mechanisms in the route BC-ECAPed Al-18%Si-4.5%Cu alloy.