Influence of the process parameters on the forming result in indirect extrusion of semi‐finished products of aluminum‐magnesium compounds

Abstract

Based on previous preliminary tests for the production of semi-finished products of Al-Mg compounds by indirect extrusion [9], the testing program was extended and further specified. In addition to varying the process parameters, analog tests for the investigation of intermetallic phases are presented. The extended test series investigate the influence of a new combination of lubricants, the initial temperature of the extrusion billet and an integrated cooling path on compound quality and strand surface. A main aspect of compound generation is the formation of intermetallic phases. In order to investigate the origin, distribution and characteristics of these phases compounds were generated by diffusion soldering. This method prevents the effects of inhomogeneous surface area increase which can occur during the formation of compounds by forming. Furthermore, inserting intermediate layers becomes much easier. These intermediate layers have considerable influence on the formation of intermetallic phases. Moreover, reproducibility of the metal compounds generated by indirect extrusion of the tested aluminum and magnesium alloys can be ensured. The process window allowing for the formation of completely bound semi-finished strand products is very narrow. Here it is especially important to ensure constant tribological conditions during forming