Research on reliability of punch bonding technology with steel-aluminum sheet metals

In order to reveal the influence of technological parameters in the punch bonding process with dissimilar sheet metals, using experimental methods in this article, laws of the influence of technological parameters on the connection in quality and reliability are analyzed systematically. The results show that the connection thickness decreases when punching load increases. When punching load increases to 28 kN, the maximum shearing load immediately presents decreasing trend after arriving at the peak, and the defects of the shearing tests change into the ring groove cracking from the bottom one. Along with increasing of X₁ and X₂, the thicknesses of the joint parts all tend to reduce, and connection strength reaches the maximum when X₂ is 1.0 mm. The technology experiment of punching bonding is performed and the results show that when the steel sheet is located at the punch side, it is easy to form an "S" type interlocking structure, whose ultimate shearing load value is about seven times larger than that of the aluminum sheet. The above results provide theoretical basis for the process development of punch bonding technology with dissimilar sheet metals and the die design.