MANUFACTURING METHOD OF DISSIMILAR METAL JOINING BODY

PROBLEM TO BE SOLVED: To provide a manufacturing method of a dissimilar metal joining body capable of improving joint strength, particularly, peel strength in a joining part of mutual dissimilar metals.SOLUTION: In a manufacturing method of a dissimilar metal joining body, a steel member 10 and an aluminum alloy member 20 for forming a through-hole 21 are overlapped in the formation direction of the through-hole 21. A droplet of an aluminum filler material of an aluminum alloy of including Si by less than 3 mass% is transferred so as to cover a through-hole 21 by AC pulse MIG welding. Thus, an aluminum alloy member 20 is formed with an aluminum melting metal coagulation part 60 of a shape of expanding to the outside of the through-hole 21 in response to the fact of separating from a joining interface 60a between the aluminum alloy member 20 and the steel member 10.SELECTED DRAWING: Figure 5 【課題】異種金属同士の接合部における継手強度、特に剥離強度の向上を図ることができる異種金属接合体の製造方法を提供する。【解決手段】異種金属接合体の製造方法は、鋼部材１０と、貫通孔２１が形成されたアルミニウム合金部材２０とを、貫通孔２１の形成方向に重ね合わせる。交流パルスＭＩＧ溶接により、Ｓｉを３質量％未満含有するアルミニウム合金のアルミニウム溶加材の溶滴を、貫通孔２１を覆うように移行させる。これにより、アルミニウム合金部材２０に、アルミニウム合金部材２０と鋼部材１０との接合界面６０ａから離れるに従って貫通孔２１の外側に広がる形状のアルミ溶融金属凝固部６０を形成する。【選択図】図５