Matrizenloses Clinchverfahren verkürzt Prozesszeiten beim temperierten Fügen von Magnesiumbauteilen

Joining by forming of magnesium alloys is restricted by the limited forming capability of magnesium at room temperature. For this reason heating of the parts to temperatures of 220 degree Celsius or more is required to form joints without cracks. Researches on State-of-the-art joining by forming methods (such as clinching or self-pierce riveting) have shown that a minimum heating time of 3 to 6 seconds is needed to achieve joints of acceptable quality. In this paper two new clinching methods "dieless clinching" and "dieless rivet-clinching" shall be introduced, that make it possible to decrease the heating time to only one second or less. The dieless clinching process was simulated using the Finite Elements Method (FEM) to analyze the influence of geometrical parameters of the punch. In dieless clinching the punch geometry has a significant influence on the formation of the joint. The length of the punch should be slightly below the total thickness of the parts to be joined for getting maximum interlock. The edge of the punch should be as sharp as possible in order to force the material to flow into the interlock and to get good joints.