Microstructure and mechanical characteristics of an in-situ synthesis of AA7075/TiB₂ metal matrix composite

Abstract

In the present study, AA7075/TiB2 aluminium metal matrix composite (AMCs) was prepared by stir casting method using in-situ reactions of inorganic salts KBF4 and K2TiF6. In this process AA7075 alloy is reinforced with different weighted percentages of (5 %wt, 10 %wt, and 15 %wt) Titanium Diboride (TiB2) particles. X-ray Diffraction (XRD) investigation reveals the presence of TiB2 particles without any formation of the intermediate phase. An optical microscope was used to examine the microstructure, which revealed that the TiB2 particles are equally distributed and that grain size reduces as the weighted percentage of reinforcement particles increases. When the weighted percentage of TiB2 reinforcement particles increased, the microhardness and ultimate tensile strength of the AA7075/TiB2 AMCs increased. Furthermore, the ductile mode of failure of the tensile specimen has been observed by fractography analysis.