Microstructural characterization of blanked surface of C5191 phosphor bronze sheet under ultra-high-speed blanking

Abstract The deformation mechanism of C5191 phosphor bronze sheet under ultra-high-speed blanking was investigated. By virtue of a DOBBY-OMEGA F1 ultra-high-speed press, the ultra-high-speed blanking test was conducted on C5191 phosphor bronze sheets with a thickness of 0.12 mm at 3000 strokes per minute. The microstructures of the blanked edges were characterized and analyzed separately by electron back-scatter diffraction (EBSD) and transmission electron microscopy (TEM). The results show that grains in the blanked edges are stretched along the blanking direction. Strong {001}〈100〉 cube textures (maximum pole densities of 9 and 12, respectively) and secondarily strong {011}〈011〉 textures (maximum pole densities of 4 and 7, respectively) are formed in local zones. Additionally, deformation twins are found in the shear zone of the blanked edges which are rotated and coarsened due to the blanking-induced extrusion and local thermal effect which can further form into sub-grains with clear and high-angle boundaries. The C5191 phosphor bronze sheet is subjected to adiabatic shear during ultra-high-speed blanking, accompanied with dynamic recrystallization.