Zinc-alloys as tool materials in short-run sheet-metal forming processes: Experimental analysis of three different zinc-alloys

In recent years, there has been an increasing demand from manufacturing industries for new tool materials such as more wear resistant zinc-alloys, with optimised characteristics regarding short-run sheet-metal parts production. Research on zinc-alloys wear resistance has been performed by a lot of research groups. However, it is very difficult to compare the wear resistance of these materials due to the fact that the investigations have been carried out with conventional methods, such as pin-on-disc or block-on-ring tests. In this paper wear resistance has been evaluated for three different zinc-alloys with different primary phase as die-tool material in forming process equipment. The method used has been the U-bending process, in which the conditions are realistic due to the complex varying load and strain during the forming process. The primary phase in ACuZinc5 is a ε-phase, which is harder and stronger than the primary phases in Norzak2 and ZA27. ACuZinc5 is almost nine times more abrasive resistant and Norzak2 is 1.8 times more abrasive resistant than ZA27. An other conclusion that can be drawn is the importance of using a methodology during the experimental work that has realistic conditions, both for the tool material and sheet-metal.