Effect of Lubrication in Cold Upsetting Using Experimental and Finite Element Modeling

Abstract

An effective lubricant will always enhance the formability of a material when applied at the die–billet interface in cold upsetting processes. High friction at the die–billet interface leads to adhesion of the cylindrical billets to the surfaces of the die, and barreling can occur. The present work focuses on the experimental and finite element investigation of the cold upsetting process of AA2014-T6 cylindrical billets under different friction conditions. The forces, stresses, and strains required for deformation were analyzed for different lubrication conditions using the finite-element-based software DEFORM 2D. The sliding velocity and sliding distance of the material are explained with the aid of computational results. The barreling radii determined from the computational techniques and analytical results were in close agreement. The influence of lubrication on stresses—namely, axial stress, hoop stress, and hydrostatic stress—was investigated. Finite element investigations were conducted for friction factors ranging from m ¼ 0 to m ¼ 1 to predict the effect of stresses on the formability of the billets.