Microstructure and Mechanical Behaviour of AZ91d Magnesium Composite Reinforced with B4C and Graphite by Casting Process

Abstract

In this study, we have manufactured AZ91D magnesium - based alloy and its composite reinforced with boron carbide (B4C) and Graphite (Gr) at various weight percentages by bottom pouring stir casting process. The work is aimed at comparing the microstructure and mechanical properties of developed composites with its matrix AZ91D magnesium alloy. The B4C reinforcement particles were added 1.5, 3, 4.5 weight percentage respectively to the matrix material and also solid lubricant graphite was added 1.5 weight percentage into composite. Density, Porosity, Rockwell hardness test, tensile test, and Optical Microstructure were evaluated. The developed composites reveal increased 11.18% hardness value when compared to base material, which could be accredited to the occurrence of B4C particles. Also, this study indicates that increase in percentage addition of B4C and graphite leads to increase in density and tensile strength of the developed composites. Optical microstructure images show the uniform distribution of particles into matrix.