Effects of Prior Solution Treatment on the Superior Strengthening of Texture Component of ECAPed Al–18Si–4.2Cu alloy

The current study investigated the effect of prior solution treatment and subsequent Equal Channel Angular Pressing (ECAP) on the microstructure and texture evolution of an Al–18 pct Si–4.2 pct Cu alloy. Microstructural analysis revealed that the solution treatment influenced the fragmentation and spheroidization of small particles, thereby limiting the effects of ECAP on the breakage of eutectic silicon particles (ESPs) and intermetallic compounds (IMCs). The effects of the solution treatment, including grain growth, the production of a super-saturated Al matrix, the presence of small precipitates within the matrix after the initial pass, and the development of strong initial textures, hindered complete dynamic recrystallization (DRX) after the initial passes. The predominant recrystallization mechanisms observed were continuous dynamic recrystallization (CDRX) and particle-stimulated nucleation (PSN). The formation of the ideal ECAP and simple shear texture components was restricted due to the strong initial texture induced by the solution treatment. Following the development of DRX, superior strengthening of {001}〈100〉 recrystallization texture component was achieved after the third pass. Subsequent ECAP pass strengthened the {001}〈310〉 component.