On the correlation between thermoelectricity and adhesive tool wear during blanking of aluminum sheets

Blanking is one of the most frequently used manufacturing processes. Its profitability strongly depends on the development of tool wear, since this determines the decisive factors of part quality, process stability and service intervals. Reducing the wear can only be achieved by gaining a sufficient understanding of the interactions which cause it. One important factor in this context is the temperature increase in the shear zone due to the partial dissipation of inelastic work. The resulting temperature gradient in the tool, combined with the electric contact between the workpiece and the tool, generates thermoelectric voltages and currents. The thermoelectric currents are suspected to have an especially strong influence on adhesive wear, but the mutual correlation between them during blanking operations is not clear. Therefore, several blanking examinations were carried out with the aluminum alloy 5083. The thermoelectric currents and voltages were measured instantaneously in the tool and their impact on the development of wear was shown by externally manipulating the occurring thermoelectricity.