ALUMINUM ALLOY MATERIAL FOR ENCLOSED BOXY SECONDARY BATTERY EXTERIOR CAN HAVING EXCELLENT BULGE RESISTANCE AND WELDABILITY, AND PRODUCTION METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a enclosed boxy secondary battery exterior can which has excellent bulge resistance and laser weldability, is further provided with strength, formability or the like required as an exterior can, and is sufficiently adaptive to thin its wall thickness. SOLUTION: The Al alloy material for the enclosed boxy secondary battery exterior can having excellent bulge resistance and weldability has a composition containing, by mass, 0.5 to 1.5% Mn, 0.05 to 0.3% Mg, =0.2% Si and 0.2% Cu, and the balance Al with inevitable impurities. The Al alloy material has electrical conductivity of =45% IACS, and a ratio between proof stress and tensile strength (proof stress/tensile strength) of 0.8 to 0.95. Thus, the Al alloy material contains suitable amounts of Mn and Mg, and in which the contents of Si and Cu are suppressed, and further, electrical conductivity is defined as =45 IACS, and a ratio between proof stress and tensile strength (proof stress/tensile strength) to 0.8 to 0.95. In this way, the Al alloy material has excellent mechanical properties, electrical conductivity, formability, weldability, swelling resistance or the like, and is therefore suitable for a enclosed boxy secondary battery exterior can of an Li ion battery or the like.