Characterization of AZ91/Al2O3 Composite produced by Infiltration Route

Nowadays, magnesium alloys are increasingly used in automotive and aerospace applications mainly due to their light weight combined with reasonable mechanical properties. However, magnesium (alloys) matrix composites are manufactured in order to improve some of the monotonic mechanical properties. In the present work, the AZ91 (Mg-Al-Zn) alloy was used as composite matrix reinforced with alumina preform through the infiltration route form interpenetrating phase composite. The obtained composite samples were characterized for the sake of comparison with monolithic properties. The dependence of composite properties was studied as a function of reinforcement volume fraction and applied pressure. Results revealed that the composites exhibited higher density and decreased porosity compared to the matrix base alloy. However, monotonic ultimate compression strength and ductility decreased. This was attributed to presence of thermal compressive stresses at reinforcement/matrix interface as well as occurrence of interfacial reaction products such as MgAl2O4 spinel phase.