Combined effect of ball milling and high-pressure torsion on mechanical properties of Al₂O₃/Al composite

Abstract During vacuum hot pressing sintering process, the Al 2 O 3 generated in situ and Al 2 O 3 /Al composite are obtained. The ball milling and high – pressure torsion is used to improved tensile properties of Al 2 O 3 /Al composite. The effects of high – pressure torsion on the distribution of Al 2 O 3 and mechanical properties of the Al 2 O 3 /Al composite are discussed. The results show that under high – pressure torsion deformation, Al 2 O 3 films coated on the surface of Al powders are broken. The Al – Al interface is formed due to the broken Al 2 O 3 . Increasing the shear deformation degree is beneficial to the consolidation of Al powders and improves the hardness of the Al 2 O 3 /Al composite. The improved ultimate tensile strength of the Al 2 O 3 /Al composite benefits from the closure of voids and the formed Al – Al interface during high – pressure torsion deformation. After high – pressure torsion, the ultimate tensile strength and hardness of the Al 2 O 3 /Al composite with the ball milled Al powders are 198 MPa and 75.2 HV, respectively.