Copper Alloy Spring Materials and Spring Properties

Copper alloys have long served as spring materials in electromechanical devices, but the miniaturization of electronic equipment has imposed new demands on these materials. The first is that of improved elastic properties to ensure satisfactory performance at the higher operating stresses and temperatures encountered in these miniaturized devices. The second is that of improved methods for characterizing those spring properties of design interest in light of the more stringent operating margins encountered in these devices. Some of the newer alloys, processing methods, and strengthening mechanisms being employed to provide copper alloys with improved elastic properties are reviewed. Thermomechanical processing is shown to be a particularly effective means for achieving high strengths in a variety of copper alloys. New methods for characterizing the elastic properties of spring materials are discussed and compared to traditional methods based on tension tests.