JOINED BODY

This joined body comprises: a main body part having wall sections that form flow channels through which flows a medium promoting heat exchange; and a cover that covers a formation surface of the flow channels of the main body part. The cover has: covering parts provided on the side facing the main body part and covering the flow channel formation surface of the main body part; groove sections provided on the side facing the main body part and accommodating tips of the wall sections; and a friction-stirred joint part which is provided on the opposite side from where the covering parts and the groove sections are provided, which is at least partially friction-stirred to a depth reaching bottom sections of the groove sections from the surface opposite the side facing the main body part, and which is joined to the tips of the wall sections. 本发明涉及的接合体，包括：主体部，其具有形成流路的壁部，该流路用于使促进热交换的介质流通；以及盖部件，其覆盖主体部的流路的形成面，盖部件具有：覆盖部，其设置在与主体部相对的一侧，并覆盖主体部的流路形成面；槽部，其设置在与主体部相对的一侧，并收纳壁部的前端部；以及搅拌接合部，其设置在与设置有覆盖部及槽部的一侧相反的一侧，在至少一部分中，从与相对于主体