Modeling of cylindrical upsetting process for enhanced ductile fracture

Abstract

The demand of the automobile and aerospace industries to produce light weight parts provides scope for analyzing the formability of AA2014 cast alloys. The addition of industrial waste like fly ash lowers the ductility and the formability characteristics needs to be investigated. Upsetting being a primary metal forming operation and the fracture initiation depends upon the amount of fly ash added to the AA2014 matrix, height to the diameter (h/d) ratio and friction at the die/billet interface. To predict the effect of these process parameters on the fracture initiation behavior Taguchi’s optimization technique was applied for cylindrical upsetting. The experimental results proved that the formability of the material depends on the lubricant employed at the die/billet interface, height to the diameter ratios and the strength parameter. The formability was measured in terms of effective strain to improve the incipient fracture. Using ANNOVA analysis, the percentage contribution of each factor was determined. Ductile fracture criterion was modified using Hills equation to determine the critical damage for any friction condition. The results obtained from the finite element simulations are in good agreement with the results obtained from the modeled empirical equation.