Development of models for predicting impact strength of Al7075/Al2O3 composites produced by stir-casting

Aluminium matrix based metal matrix composites (MMCs) are being extensively used in various industrial applications that need high strength combined with low weight, high hardness, wear resistance, high temperature resistance, improved impact strength, etc. They are amenable to secondary manufacturing processes such as extrusion, rolling, forging, welding, etc. However, because of their complex nature, both in terms of composition and difficulty in manufacturing by the standard fabrication techniques, researchers are keen to study various combinations of constituent materials - matrix and reinforcement, their processing, property evaluation, and extending their applications in various fields. This article presents the details of the investigation comprising stir casting of Al7075 matrix material reinforced with Al2O3 particulates. An attempt has been made to predict the impact strength of these MMCs, which is an important property that decides their suitability in shock loading environment, both in the as-cast and forged conditions. Multi-factor, rotatable, central composite design has been used to predict the impact strength in terms of charpy-V. The mathematical models developed are validated using Fisher's F-test.