メカニカルクリンチングの剥離強度に及ぼす潤滑油粘度の影響

抄録

Mechanical clinching is a mechanical joining method that has been attracting considerable attention as an alternative to spot welding or riveting, because of the many advantages it offers in assembling aluminum panel parts. However, the applications of this method are limited because it affords low peeling strength; therefore, it is necessary to improve the peeling strength. In this study, various effects of lubricant viscosity are investigated to clarify the factors influencing the peeling strength. The following observations were made with regard to the different lubricated surfaces studied. In the case of the boundary surface, peeling strength improves when the lubricant viscosity is sufficiently low for adhesion and seizing to occur. In the case of the tool surface, peeling strength decreases with a decrease in lubricant viscosity because of cross-sectional shape deformation. From the above results and results of finite element method, it is revealed that the frictional force between tools and workpiece surfaces resisting material flow plays an important role in determining the cross-sectional shape of mechanical clinching. Additionally, to achieve good cross-sectional shape, the direction of the metal flow should be controlled; this can be achieved by following some of the guidelines we proposed to achieve higher peeling strength.