Statistical investigation on tensile strength of friction-welded joints of stainless steel to copper

Abstract

Friction welding of SUS304 stainless steel to C1100 tough pitch copper was carried out and tensile strength of joints was examined. Also, a statistical analysis of the tensile strength data was investigated for judging a suitability of friction welding conditions on this joint. It was found that the SUS304 and the C1100 near the weld interface hardened and softened, respectively. There were fine-grained structures composed of much copper and a little of iron, chromium and nickel near the axial center at the weld interface. Tensile strength tended to increase with a friction time and with an upset pressure, and the maximum joint efficiency for the C1100 base metal was 101%. The shape parameter in Weibull distribution increased with an increase in mean value of tensile strength and with a decrease in dispersion of tensile strength. It seemed that the shape parameter is useful for judging the suitability of friction welding conditions.