Synthesis and characterization of Al matrix composites reinforced by in situ alumina particulates

An optimum route to synthesis the Al(Zn)/in situ Al2O3 composites with sound microstructure and improved physical/mechanical properties have been investigated. The exothermic dispersion (XD) process (XD™, exothermic dispersion) has been followed to process aluminium composites containing various volume fractions of Al2O3 particles. In addition, the microstructure, hardness, density, porosity and wear behavior of the composites have been examined. During sintering the reaction between Al and ZnO to form Al2O3 (p) dispersion in Al(Zn) matrix is confirmed by the XRD results. The densification of the composites during sintering has been investigated at 950 °C for the different sintering times. The hardness and density of the composite increase with the increasing sintering time and reinforcement volume fractions. The wear tests show that the wear resistance of Al MMCs increases with the increase in the reinforcement volume fraction and sintering time.