Copper alloys for watch industry - contg zinc, nickel, silicon, lead and copper, heat-treatable before and/or after deformation

摘要

Watch pts., mechanisms and cases for mechanical and electronic clocks consist of Cu alloys contg. 25-31% Zn, 2-6% Ni, 0.5-3% Si, 1-3% Pb, bal. esp. 64,5% Cu. In specific processes, punching, or warm- but partic. cold-pressing, are preceded by 1-3 hrs. heat-treatment at 700-900 degrees C, followed by quenching, esp. in water, and pref. hardening at 150-300 degrees C for 1-3 hrs. under a protective atmos. or in vacuo. Strength is raised by hardening after deformation, at 300-400 degrees C for 0.5-4 hrs. In a further embodiment of invention, alloy is heat-treated at 700-900 degrees C for 1-60 min. before deformation and cooled in hot-pressing.