This work deals with aluminium alloys, which are used in high voltage cables. The aim is to investigate possibilities which result in a better combination of strength and conductivity. Stress-strain diagrams are used to determine the tensile strength and resistance measurements are utilized to determine the electrical conductivity. The first section of the thesis summarizes the current state of knowledge from the literature. These findings and the methods used form the basis of the experiments. In principle, the experiments carried out are divided into three sections. The first category contains all those experiments that are examined on the undrawn wire. Here, metallographic investigations determine the grain size. The heat treatment condition is studied via transmission electron microscope and the hardness is investigated by Brinell hardness testing. The second category of experiments includes examinations on the drawn finished wire. Here, variations of heat treatments are carried out. The focus is on the determination of the solution annealing temperature, the influence of pre-ageing, an interrupted drawing process with subsequent artificial ageing or the influence of over ageing The third category of experiments includes further experiments like the preparation of a reference sample for comparison of the heat treatment tests with industry, or the production and investigation of an ultra-fine grained aluminium alloy. Since a large number of results from different experiments are available and strength and electrical conductivity must always be considered together, the results are always compared in bar charts. The work is intended to serve on the one hand to improve today's overhead lines, and on the other hand as a stimulus for further research.