Numerical Investigation of Upsetting and Transverse Extrusion Process for 'Rod with Flange' Parts and Preforms Production Made from Aluminium Alloy 1013

摘要

Even a simple cold forming operation takes into account many technological parameters and has advantages comparing to the hot forming technology (e.g. hardening for massive parts). The right choice of technological parameters can result to high economic benefits in a mass production. The main restriction of the well-known methods of cold forming of "rod with flange" parts (e.g. bolts and screws) production is the possibility of the buckling of workpiece in a longitudinal direction if the upsetting length-to-the diameter ratio (L/D) of the deformed length is either equal or more than 2.5. To increase the efficiency of a technological operation it is suggested to apply spring-loaded lower die. To investigate the influence of the friction forces, different values of the friction factors were assigned on the contact surfaces. The process was simulated using FEM-code QFORM. The head height of the deformed workpiece was taken as a merit of accuracy during the simulation. In addition, the head shape and metal flow due to friction changes were investigated, as well. The results shown in this paper were confirmed by experiments, carried out on aluminium wrought alloy AA1013 using different lubricants.