The influence of the temperature of solution heat treatment on the properties of 6000 series aluminium alloys

Abstract

The 6000 series alloys belong to the group of aluminium alloys that contain magnesium and silicon as their two main alloying elements. In addition to these two alloying elements, the alloys contain manganese and other elements, in accordance to the type of alloy. Alloys from this series belong to the group of aluminium alloys which are susceptible to thermo-mechanical treatment. These alloys exhibit the best mechanical and physical properties when they are artificially aged, with the occurrence of the strengthening β'' phase. The process of ageing includes solution heat treatment, quenching and ageing at predefined temperatures for a specified amount of time. All the aforementioned processes have a direct impact on the physical and mechanical properties of the alloy following the performed thermal treatment. In this paper the influence of the temperature of solution heat treatment on the properties of two aluminium alloys belonging to the 6000 series was examined, EN AW-6060 and EN AW-6082. The samples were examined at five different temperatures varying from 510-590°C. In order to examine the influence of the temperature of solution heat treatment, measurements of the hardness and electrical conductivity of the samples were performed, following adequate thermal treatment. After the testing, analysis of the results showed that with the increase of the temperature of soluble annealing, there occurred an increase in hardness, and a decrease in electrical conductivity in the aged samples, due to a better homogenization which caused a better distribution of metastable phases.

Keywords

• aluminium alloys
• heat treatment
• hardness
• electrical conductivity