Method for joining dissimilar metals, joined body, and joining apparatus

A method for joining dissimilar metals in which a first member having a plate shape and containing first metal is butt-joined to a second member having a plate shape and containing second metal having a melting point higher than that of the first metal using frictional heat, the method comprising:

• overlapping an end portion of the second member on an end portion of the first member;
• and
• pressurizing the second member toward the first member by bringing a rotating joining tool having a protruding portion at a tip end into contact with an overlapping portion of the second member with the first member,
• when the second member is pressurized toward the first member, the tip end of the rotating joining tool being not in contact with the first member,
• wherein:
• in overlapping the end portion of the second member on the end portion of the first member, the first member and the second member are placed on a backing, and
• in pressurizing the second member toward the first member by bringing the rotating joining tool into contact with the overlapping portion of the second member with the first member, a part of the first metal discharged from a joining face between the first member and the second member is discharged to a recessed portion provided on a surface of the backing.