Metal laminate and manufacturing method of metal laminate

A metal laminate, comprising:

• a laminate, in which a first metal plate and a second metal plate are laminated,
• wherein the first metal plate includes a caulking that exhibits a mountain shape protruding from a back surface side of the first metal plate and recessed on a front surface side of the first metal plate, and
• the second metal plate includes an accommodating portion configured to accommodate the caulking of the first metal plate such that the caulking is fitted to the accommodating portion,
• wherein the caulking of the first metal plate includes:
• a recessed portion provided on an inner concave surface of the caulking and recessed toward the back surface side of the first metal plate;
• and
• an abutting portion abutted against an inner surface of the accommodating portion of the second metal plate at a position corresponding to the recessed portion,
• wherein a metal density of the abutting portion of the caulking is higher than a metal density of a remaining portion of the caulking.

A metal laminate manufacturing method, comprising:

• providing a first metal plate and a second metal plate, wherein the first metal plate includes a caulking that exhibits a mountain shape protruding from a back surface side of the first metal plate and recessed on a front surface side of the first metal plate, and the second metal plate includes an accommodating portion configured to accommodate the caulking of the first metal plate;
• and
• laminating the first metal plate and the second metal plate such that the caulking of the first metal plate is fitted to the accommodating portion of the second metal plate,
• wherein the laminating of the first and second metal plates includes:
• pressing a push punch, which is provided with a protrusion on a tip end surface thereof, against an inner concave surface of the caulking of the first metal plate to form a recessed portion in the inner concave surface of the caulking;
• and
• forming an abutting portion in the caulking, configured to be abutted against an inner surface of the accommodating portion of the second metal plate at a position corresponding to the recessed portion when the caulking is fitted to the accommodating portion.