Microstructural characteristic and mechanical properties of the in-situ MgAl2O4 reinforced Al matrix composite based on Al-Mg-ZnO system

Abstract

In-situ synthesized Al matrix composites (AMCs) have drawn lots of interest recently relying on the designability of reinforcement configurations and promising mechanical properties. In this work, a new generation of AMCs reinforced by in-situ MgAl2O4 particles was fabricated based on Al-Mg-ZnO system using shift-speed ball-milling (SSBM) combined with reactive sintering method. The detailed microstructural characterization and comprehensive thermodynamic analysis rationalized the in-situ reaction mechanism, in which the substituted MgO was involved in the formation of homogeneously dispersed MgAl2O4 that forms robust interfacial bonding with matrix. In addition, the coefficient of thermal expansion mismatch strengthening and grain refinement acted in concert to render the impressive mechanical properties, achieving the yield stress of 347 MPa and ultimate tensile stress of 505 MPa. This work can be informative for the fabrication of high-performance in-situ MgAl2O4 reinforced AMCs based on Al-Mg-oxides system.