Experimental Investigation and Evaluation of Joint Strength of A356/Mg Bimetallic Fabricated Using Compound Casting Process

摘要

In the present work, two lighter materials (pure magnesium and aluminum alloy A356) were joined together by vacuum-assisted sand mold compound casting process. The dominating process parameters such as pouring temperature, insert temperature, surface roughness of insert and vacuum pressure were chosen to execute the casting process. Microstructure of joint interface was analyzed by SEM, EDS and XRD techniques. Mechanical properties, namely, microhardness, impact and shear strength of joint, were measured experimentally. The accuracy of experimental data was checked by using response surface methodology. The joint strength of A356/Mg interface was evaluated by applying graph theoretic approach (GTA). A numerical value, joint strength index, was proposed to show the effect of factors and subfactors. Index values of subsystems revealed that shear strength has maximum influence on joint strength followed by microhardness and impact strength. GTA proves an effective tool in estimating the optimum process parameters for compound casting process.