Microstructures and tensile properties of Al/2024-Al4Sr composite after hot extrusion and T6 heat treatment

Microstructures and tensile properties of Al-2024 matrix composite containing 10 wt% Al4Sr intermetallic have been studied after extrusion process and T6 heat treatment. Microstructural examinations were assessed by the use of optical microscopy, scanning electron microscopy (SEM) and X-ray diffractometry. The results showed that changing the matrix from Al to 2024 alloy reduces the length of primary Al4Sr particles and improves ultimate tensile (UTS) values considerably from 206 MPa to 321 MPa which is based on the formation of Cu-rich intermetallics. Applying extrusion process and T6 heat treatment was found to be very effective in enhancing tensile properties of Al/2024-10Al4Sr composite. In current research, UTS and elongation values were found to be 381 MPa and 13.6%, introducing a tough composite. Moreover, the study of fracture surfaces of the hot-extruded composites specimens revealed that ductile mode of fracture is dominant.