Effect of extrusion conditions and cooling rate for quench on mechanical properties of 6061 aluminum alloy extrusions

摘要

Effects of extrusion conditions (temperature and speed) and cooling rate during quenching on tensile properties of 6061 aluminum alloy extrusion after T6 treatment are studied in relation to microstructures. Materials were ex-truded at the temperature of 673 K and 803 K and at the speed of 2.83 x 10~(-2)~2.33 X 10~(-1) m/s, quenched at the cooling rate of 1.0~83.3 K/s after the solution treatment at 803 K-10.8 ks, and aged at 453 K-28.8 ks. 0.2 percent proof stress and tensile strength are higher when the temperature and speed of extrusion are high, or when the cool-ing rate during quenching is high. This is related with grain size and amount of solute Mg and Si after quenching. Elongation is lower at the cooling rate of 4.3~6.3 K/s in quenching. This is dependent on the large precipitates at grain boundaries.