Effects of heat treatments on the microstructure and mechanical properties of a 6061 aluminium alloy

▶ Description of the mechanical behavior of AA6061-T6 at RT after various thermal histories. ▶ A fast-heating device has been designed to reproduce those thermal histories on tensile specimens. ▶ The thermal loadings are representative of the temperature change observed in the HAZ during welding. ▶ The variation of mechanical properties is the result of metallurgical evolution observed by TEM. ▶ The yield stress at RT decreases with the maximum temperature reached during the thermal cycle. This paper describes the mechanical behavior of the 6061-T6 aluminium alloy at room temperature for various previous thermal histories representative of an electron beam welding. A fast-heating device has been designed to control and apply thermal loadings on tensile specimens. Tensile tests show that the yield stress at ambient temperature decreases if the maximum temperature reached increases or if the heating rate decreases. This variation of the mechanical properties is the result of microstructural changes which have been observed by Transmission Electron Microscopy (TEM).