| 摘要 |
A copper/aluminum joined structure having a hot-dip- aluminized steel sheet (1) and, laminated thereon by spot welding, aluminum or an aluminum alloy (2), wherein a plating layer (4) comprises 3 to 12 mass % of Si and 0.5 to 5 mass % of Fe, the area percentage of an Al-Fe binary alloy layer (7) in its joining interface is suppressed to 90 % or less, and a region (9) having no alloy layer appears between an Al-Fe-Si ternary alloy layer (6) being present in a base steel (5)/plating layer (4) interface and the Al-Fe binary alloy layer (7); and the above copper/aluminum joined structure which uses a plated steel sheet (1) having a base steel(5) comprising 0.002 to 0.020 mass % of N and having an N-rich layer containing 3.0 atomic % or more of N formed on its surface contacting with the hot dip aluminizing layer (4). The above copper/aluminum joined structure, particularly, the latter one is inhibited in the extension of the Al-Fe binary alloy layer (7), which is low in strength, and as a result, exhibits improved steel/aluminum joining strength. |
