Effects of activation treatment on interfacial bonding in A356-10 wt% B4C composite sheets prepared by rheo-rolling

Abstract

A novel semisolid stirring and rheo-rolling process for preparing aluminum- boron carbide composite sheets was proposed. The microstructure and interfacial bonding of A356-10 wt% B4C composites were investigated. The activated B4C particles had no impurities on the surface. Furthermore, no particles with an acute angle were observed, which contribute to improved wettability between the B4C particles and the aluminum matrix. The strengthening phases Al3BC and Al2O3are formed on the interface between particles and matrix, resulting in chemical bonding. A356-10 wt% B4C composite sheets with good mechanical properties were fabricated via the combination of semisolid stirring and rheological rolling. The Vickers hardness of the composite sheet with activated B4C particles reached 109 HV, and the tensile strength reached 197 MPa.