We have studied the effect of electroslag remelting on the content and composition of non-metallic inclusions. It was found that a decrease in the non-metallic inclusion content occurred during the electroslag remelting. A change in the chemical composition of the non-metallic inclusions was observed, while the aluminum and calcium contents were increased. The complexity of the inclusions also increased, as there were fewer single-phase inclusions after the electroslag remelting process. Based on the results and a thermodynamic assessment of the formation of the non-metallic inclusions, a mechanism for inclusion behavior during electroslag remelting has been proposed.

In order to eliminate the separate solution soaking treatment used for Al–Cu extrudates, the influence of billet heat treatments before the extrusion process on a precipitation hardenable AlCu6PbBi (AA2011) alloy was studied. The hot deformation behaviour of the alloy was studied using compression tests. A comparison of the conventional extrusion process, press quenching and billet quenching (BQ) before extrusion was made in production on a 35 MN press. The transformation kinetics was studied by heat treating homogenised samples in salt baths. The mechanical testing, using tensile tests and the Brinell hardness test, and a microstructural investigation, using light and TEM microscopy, revealed that extrusion using the billet quenching process results in the formation of extrudates with similar mechanical properties, hardness and microstructures as those produced using conventional technology. In the extrudates produced by BQ a supersaturated solid solution is formed directly after cooling in a standing water wave, which makes BQ an efficient and reliable substitute for the conventional extrusion process.