2010 年 51 巻 589 号 p. 141-145
The joinability of mechanical clinching for high strength steel sheets with a low ductility and an aluminum alloy A5052 sheet was improved. For the upper steel sheet, a fracture was observed around the punch corner. For the lower steel sheet, cracks appeared around the die corner. To prevent the fracture and cracks of the steel sheets, the concentration of deformation was relaxed by modifying the shape of the die. The effect of the die shape on the deforming behavior of the sheets was investigated by finite element simulation and experiment. The joinability for high strength steel and aluminum alloy sheets was improved by modifying the depth and diameter of the die. The strength of the joined sheets was measured by a cross-tension test. The fracture in the test appeared at the aluminum alloy sheet. As the tensile strength of the steel sheet increased, the strength of the joined sheets decreased because of the small interlock of the joined sheets.