Effect of Intermediate Annealing Temperature and Aging on the Mechanical Properties and Conductivity of Al–0.2Mg–0.35Si–0.3Ce Wire Rod

The present study investigated the effect of intermediate annealing temperatures on the microstructure, mechanical properties and conductivity of Al–0.2Mg–0.35Si–0.3Ce wire rod, which experienced hot extrusion (named as E), cold drawing (named as D), annealing (named as A) and cold drawing, i.e. EDAD. And four intermediate annealing temperatures (150, 200, 250, 300 °C) were carried out for investigation. Microstructure observation shows that no recrystallization occurs in the wire rod when annealed at 150 and 200 °C. However, it occurs when the annealing temperature reaches 250 °C. Tensile tests indicate that the ultimate tensile strength (UTS) of the as-EDAD samples firstly increases to a maximum value of 218 Mpa when the annealing temperature increased to 150 °C, and then decreases dramatically with the temperature continuously increasing. However, the elongation and conductivity of the as-EDAD samples just go oppositely. The conductivity of the sample annealed at 300 °C reaches 57.1%IACS, which is about 3.3%IACS higher than that of the sample without annealing. The effect of aging (190 °C for 20 h) on the mechanical properties and conductivity of as-EDAD samples was also investigated. Results show that the variation trend of UTS, elongation and conductivity of the EDAD-aging samples is similar to that without aging. The UTS decreases after aging, however, elongation and conductivity both increase.