Evaluation of cutting surface quality in high speed blanking process

Blanking process holds a crucial point in metal forming industry. The main goal in blanking is to achieve the best surface quality on the blanked parts while spending minimum energy. In this study the surface quality, cutting load and cutting energy of the workpieces were investigated under three different speeds (0.1 m/s, 1 m/s and 10 m/s) with respect to the clearance, material thickness and thickness to die diameter ratios. Five different clearances (1%, 3%, 5.%, 10.0% and 20.0%) were used to blank 2 mm, 3 mm and 4 mm thick workpieces made of AISI 304 stainless steel under four different ratios (t/Dm=1/5, t/Dm=1/10, t/Dm=1/30, t/Dm=1/50). Both experimental and FEM studies were accomplished. Results showed that increasing punch speed improves the surface quality and best surface quality was achieved at 10 m/s by reaching lowest surface roughness values. Another important contribution is the thickness to die diameter ratio and found out that energy, surface quality and related clearance values change according to the workpiece diameters that are neglected in the literature which only considers the thickness of workpiece. The total energy increases due to increasing punch speed, thickness and thickness to die diameter ratios. Clearance between 3% and 5% is found to be optimal value range for AISI 304 stainless steel when considered all investigated parameters.