The tool surface wear during the silicon steel sheets blanking process

Production of the sheared blank elements, with a certain quality, requires an optimal process parameters selection [4, 6, 11, 30]. Gréban et al. in their work [6] presented the effects of copper alloy elements blanking process. Tekiner et al. [30] described the result of experimental analysis of the aluminum alloy element blanking process. Hernández and other authors [11] presented the influence of the punch cutting edge geometry changes on the cut surface quality. They described the influence of the blanking process clearance and punch diameter. The study concerned the acid resistant steel sheet (AISI 304). There is some dependence between the burr height changes and the punch wear during the blanking process. Study of the high-steel punch wear, for punches with front edge slopped, was presented by Cheung et al. [4]. Blanking process causes the sheet material structure changes. The case of aluminum element blanking process was analyzed by Ravela et al. [28]. The tool surface wear during the blanking process causes changes of the cut surface quality [8, 9, 14, 17÷19]. The value of the cutting edge radius significantly affects on the blanking process energy consumption [16]. Tool wear, geometry and clearance influence on the burr height. The bur height can be reduced by using an appropriate tool arrangement. Electrical steel sheets used in electrical machines have a relatively high induction, permittivity and good punchability. The sheet material magnetic properties are determined in the production process [31]. For the evaluation of the sheet punchability many criterions can be used, and the most important are: sheared blank part deformation resistance, – the burr height, – coating damage resistant during blanking process, – material strengthening close to the cut surface, – geometrical quality of the sheared blank sheet material, – cutting tools durability, – intersection surface quality of the sheared blank parts. –