Computer modelling of low-melting-point materials semicontinuous direct extrusion temperature conditions

The heating of metal and tooling caused by deformation processes and contact friction is the reason for a decrease in the finished product quality and a loss of process stability during cold direct extrusion of low-melting-point materials. PJSC Chelyabinsk Zinc Plant together with the Department of Metal Forming Processes and Machines of SUSU has been actively and successfully developing and mastering the technology for the production of wire and rod solder from POIn-52 alloy. A computer simulation of the extrusion process temperature conditions of the POIn-52 alloy wire with a diameter of 2.0 mm at an extrusion speed of 0.5; 1.0 and 3.0 mm/s from a workpiece with a diameter of 20 mm was carried out in this work, using a specialized engineering package QForm. Based on the results of computer simulation, it has been established that the speed of metal outflow from the die, which in turn is determined by the extrusion speed and the extrusion ratio, has a significant effect on the pressing process temperature conditions. The metal temperature increases from 33.4 to 75.8 °C, when the extrusion speed changes from 0.5 to 3 mm/s in the extrusion process of wire Ø2.0 mm from a billet 20 mm. Moreover, it should be noted that sequential extrusion of four blanks leads to an increase in the wire temperature from 75.8 to 87 °C. This is due to the fact that in the process of continuous extrusion the tooling, namely the drawing die, heats up and after the fourth extrusion cycles its average temperature is about 45 °C. The average container temperature rises by 4 °C. A further increase in the temperature of both the metal being extruded and the wire on the investigated diameter of the solder stops and the process stabilizes after the fourth cycle.