INFLUENCE OF PRECIPITATION STRENGTHENING PROCESS ON THE MECHANICAL PROPERTIES OF 6082 WROUGHT ALUMINIUM ALLOY

摘要

Aluminium alloys containing Mg and Si as the major solutes are strengthened by precipitation of the metastable precursors of the equilibrium beta (Mg_2Si) phase in one or more sequences. There are several particles that can form during aging: GP zones and intermediate metastable phases -beta", beta' and stable beta phase [1-10]. Although the precipitation process in Al-Mg-Si alloys has been extensively studied, the understanding of the hardening process is still incomplete, since any change in composition, processing and aging practices could affect the precipitation hardening behaviour [3-6, 10]. In this paper differential scanning calorimetry (DSC), transmission electron microscopy (TEM), and hardness measurements have been utilized to study the effect of the precipitation hardening on the mechanical properties in aluminium alloy 6082. The mechanical (R_m and R_(p0.2)) and plastic (A) properties of the alloy were evaluated by uniaxial tensile tests at room temperature. The results show that the microstructure and mechanical properties change during artificial aging due to the precipitation strengthening process. Therefore, the parameters (time and aging temperature) of precipitation strengthening process that may lead to the most favourable mechanical properties of 6082 alloy were determined.