Structural Modification and Mechanical Properties of Cu-3wt%Si-xwt%Sn Alloy

Abstract

This study examined the structural modification and mechanical properties of silicon bronze doped with different concentrations of tin. The dopant was added in concentrations of 0.1, 0.3, 0.5, 0.8, 1 and 1.5wt%. The samples were developed using permanent die casting technique and machined to the required dimensions for the structural analysis and mechanical tests. Mechanical properties such as percentage elongation, ultimate tensile strength and Brinell hardness of the developed alloys were investigated using a 100KN JPL tensile strength tester (Model: 130812) and portable dynamic hardness testing machine (Model: DHT-6) respectively. The structural analysis was conducted using an optical metallurgical microscope (Model: L2003A) and scanning electron microscopy (SEM). The surface morphology of the control sample (Cu-3wt%Si) consisted of segregated primary silicon and coarse intermetallic phase (Cu3Si). Addition of tin to the studied alloy significantly refined and modified the segregated primary silicon and coarse intermetallic phases into spherical pattern evenly dispersed in the alloy structure. The percentage elongation, ultimate tensile strength and hardness of the alloy were improved significantly by addition of 0.1wt%Sn. The ultimate tensile strength and hardness of the alloy increased with increase in tin content with corresponding decrease in percentage elongation