Correlation of the Structure, Mechanical and Physical Properties of Cu- 3wt%Si-xwt%Sn Silicon Bronze
Keywords:
Electron scattering; mechanical properties;physical properties; silicon bronze; grains.Abstract
This research investigated the correlation of the structure, mechanical and physical properties of Cu-3wt%Sixwt%
Sn silicon bronze. The effect of tin content on the structure, mechanical and physical properties of Cu-
3wt%Si-xwt%Sn silicon bronze was also investigated. Tin 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, physical and mechanical tests. Mechanical properties such as percentage
elongation, ultimate tensile strength and hardness of the developed alloy were investigated using a 100KN JPL
tensile strength tester (Model: 130812) and portable dynamic hardness testing machine (Model: DHT-6)
respectively. The physical properties such as electrical resistivity and conductivity were also determined using
standard Ohm’s experiment. The structural analysis was conducted using an optical metallurgical microscope
(Model: L2003A) and scanning electron microscopy (SEM). The microstructural analysis of the control sample (Cu-
3wt%Si) revealed the presence of segregated primary silicon and coarse intermetallic phase (Cu3Si). The surface
morphology of the doped alloy consisted of refined and modified intermetallic phases evenly dispersed in the alloy
structure. The mechanical tests results showed that the percentage elongation, ultimate tensile strength and hardness
of the alloy increased significantly by addition of tin. The ultimate tensile strength and hardness of the alloy
increased with increase in tin content with corresponding decrease in percentage elongation. It was also observed
that the electrical resistivity of the alloy increased with corresponding decrease in electrical conductivity by addition
of 0.1wt% of tin. Results obtained also showed that the ultimate tensile strength and hardness correlate with
electrical resistivity while the percentage elongation correlates with electrical conductivity. This was concluded to
be as a result of grain refinement of the alloy structure by tin addition which caused scattering of electrons, hence
increased the electrical resistivity with corresponding decrease in electrical conductivity of the alloy.
