Joined body and process for manufacturing the same

A joined body having a joint,

• the joint comprising:
• a first plate-shaped workpiece comprising a first metal;
• a second plate-shaped workpiece comprising a second metal;
• and
• at least a part of the first plate-shaped workpiece and at least a part of the second plate-shaped workpiece being overlapped each other;
• the joint being made by joining the first plate-shaped workpiece and the second plate-shaped workpiece to each other by means of friction stir joining, wherein a rod-shaped body comprising a third metal is disposed at a part where the first plate-shaped workpiece and the second plate-shaped workpiece overlap each other, and then the first plate-shaped workpiece and the second plate-shaped workpiece are rotated relatively with respect to the rod-shaped body while pressing the rod-shaped body onto the first plate-shaped workpiece;
• and
• the joint further comprising:
• a coalesced section being made of the first metal that coalesces on a surface of the second plate-shaped workpiece;
• a built-up section being made of a leading end of the rod-shaped body that is buried in the first plate-shaped workpiece;
• and
• a composite section being disposed between the coalesced section and the built-up section, and being made of the first metal and the third metal that are intermingled with each other, thereby integrating the coalesced section with the built-up section.