Influence of Solutionizing Conditions on the Microstructural and Mechanical Behavior of cast Cu-6Sn ASTM B505 Bronze Alloy for Defense Applications
摘要
The Cu-6Sn alloys of dimensions 36 mm diameter and 150 mm length were cast and subjected to a thermal processing sequence of solutionizing, brine quenching, and aging. Permanent mold casting under inert conditions was used to fabricate the alloy. A comprehensive analysis of the morphological evolution and mechanical behavior of these alloys subjected to various solutionizing parameters of (780 °C, 6 h), (820 °C, 6 h), and (860°C, 6 h) was conducted using optical microscopy, X Ray diffraction (XRD), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), and tensile test which gave an insight into the presence of homogeneous α-Cu phase, intermetallic compound, preferential orientation, dislocation density, fracture features, and mechanical strength, respectively. In comparison with (820 °C, 6 h) and (860 °C, 6 h), a strain-free recrystallized microstructure with refined grain size and lower misorientation was obtained for (780 °C, 6 h). The ultimate tensile strength and yield strength were also highest at approximately 292 and 228 MPa, respectively, at (780 °C, 6 h). The absence of a preferential orientation with a random texture at the optimum solutionizing parameters of (780 °C, 6 h) and a substantial reduction in dislocation density and dendrites enhance the mechanical behavior of the Cu-6Sn alloy with high percentage elongation which is highly desirable in defense applications.