Forming and fractographical characteristics of Copper-Nickel-Beryllium sheets under tension and bending

Formability and its fracture characteristics are critical factors in fabricating spring components from sheet base materials. Copper-nickel-beryllium (C17510) alloys provide excellent formability for producing highly reliable connectors used in electrical and electronic applications. The formability of a commercially available CuNiBe alloy was studied with emphasis on springback evaluations. Experiments were conducted to investigate the forming related tensile and bending properties. Fractographical examinations were conducted to identify the characteristics of failure and predict its initiation. Several analytical formulas for predicting springback are presented herein to provide a simple tool for computer-assisted design of spring components. To verify their reliability, the analytical predictions were first compared with the experimental data. Then predictions based on different formulations were compared with each other to identify an appropriate formula to be used in design of the highly reliable spring components.