Optimization and experimental evaluation of the Al1100 and SS202 cylindrical cups using conical die without blank holder

Abstract

Deep drawing is the most widely used process for forming cup shaped products in automobile, aerospace, and packing industries. In this research, the deep drawing process is used to draw the cylindrical cups of Al1100 and SS202 metal sheets using a new type of conical die and a flat-bottomed punch without a blank holder. The experiment included in this work used blank diameters of 50, 55, 60, and 70 mm, tested under both dry and lubricated conditions. The findings indicated that the lubrication significantly reduced defects such as deflection, spring-back, earing, and uneven depth. A blank diameter of 60 mm is optimal for defect-free cups. In addition, the research observed that lower friction coefficients corresponded to required load. The deep drawing procedure has distinctive effectible process parameters from which an optimum level of parameters and defect-free cups with required mechanical properties can been obtained. Thus, using the mixed response surface methodology for optimization, the research showed an excellent decrease in the maximum required load, mainly under lubricated conditions. In brief, the optimization model for SS202 under dry conditions became incredibly accurate, with less than 1% error compared to experimental results. On the other hand, for Al1100 under dry conditions, the model’s predictions deviated more, showing more than a 12% error, indicating a need for additional refinement or extra factors to enhance the accuracy of Al1100.