Characterization and Evaluation of Mechanical Properties of Al-Zn Based Hybrid Metal Matrix Composites

Abstract

Hybrid aluminium matrix composites are preferred for structural applications due to their tailored material properties. In the current study, aluminium-7029 alloy with boron carbide (5, 10, and 15 wt%) and a constant weight percentage of graphite (5 wt%) were produced by the stir casting route. Scanning Electron Microscope and X-Ray Diffraction were used to characterize the composites. The cast alloy and hybrid composites were evaluated for physical (density and porosity) and mechanical (hardness, tensile, compressive and impact) properties by experimental and statistical methods. The porosity of the cast samples was minimal (<5%) and the hybrid composite weight decreased (2.4%) with the increase of reinforcements as revealed by the density test. Al7029/15wt%B4C/5wt%Gr (sample C3) hybrid composite hardness (126 BHN) and compressive strength (586.841 MPa) were found to be the best to get the better property with more reinforcement. Tensile (253.455 MPa) and impact strength (7 J) were the highest for the Al7029/5wt%B4C/5wt%Gr (sample C1) hybrid composite. Results obtained by a regression model developed using MINITAB were in good agreement with experimental values. The additions of B4C and Gr were found to improve mechanical properties significantly, as confirmed by analysis of variance.