Copper alloy for electronic and electric appliances, copper alloy plastically worked material for electronic and electric appliances, copper alloy plastically worked material for electronic and electric appliances, method for producing plastic worked material, parts for electronic and electric appliances and terminals

摘要

PROBLEM TO BE SOLVED: To provide a copper alloy for electronic/electric equipment, which alloy is particularly excellent in strength, flexural characteristics, and stress relaxation resistance characteristics and suitable for a component (for electronic/electric equipment) such as a terminal of a connector or the like, a relay and a lead frame, and to provide a copper alloy plastic working material for electronic/electric equipment, and the component and another terminal for electronic/electric equipment.SOLUTION: The copper alloy for electronic/electric equipment contains 3.3-6.9 atomic% of Mg and the balance consisting essentially of Cu and inevitable impurities and has 10% or higher special grain boundary length ratio (L/L). When 1,000 mor larger measurement area is measured by 0.1 m measurement interval by using an EBSD method, the measured data are analyzed by excluding such a measured point that the CI value analyzed by a data analysis software OIM is 0.1 or smaller, such a boundary between the adjacent measured points is defined as a crystal grain boundary that an orientation angle therebetween exceeds 15°, and a ratio of the sum L of each of boundary lengths of 3, 9, 27a, and 27b to the overall length L of crystal grain boundaries is defined as the special grain boundary length ratio (L/L).