Shearing of light metal sheets using hard-film-coated tools

Abstract

In shearing process, such as blanking or piercing on the sheets of both aluminum and magnesium alloys, there are problems that large burrs generate and the accuracy of cut surface is worse after a few repetitions of these processes. Therefore, in this study, we investigated the cause and solution of these problems. We found that the cause was not the deterioration of the tool edge due to wear or chipping, but that materials of the sheared sheets which adhered to the side of the tool shaved the cut surfaces of the sheets during shearing or adhered to the cut surfaces and induced partial plastic deformation. We also found that a hard-carbon-film-coated tool is effective in preventing the generation of adhesive materials, thereby preventing both the generation of large burrs and the decrease in the accuracy of cut surfaces.