Abstract:
In response to the issue of over-aging softening in the heat-affected zone (HAZ) of 6061-T6 aluminum alloy during welding, which is caused by excessively high local peak temperatures, a novel approach is proposed. This method involves applying a rotational impact during the welding process to the over-aging softened zone of the weld joint, thereby inhibiting the softening of the weld joint. Microstructural and hardness tests were conducted on the HAZ of the joint under the influence of the rotational impact during welding. The results indicate that the hardness of the HAZ significantly increases under the rotational impact, with a reduction in the size and an increase in the number of precipitated phases within the softened zone, effectively mitigating the degree of softening. Using Material Studio software, the relationship between the main aging precipitation phase transformation and stress in 6061 aluminum alloy under ideal conditions was analyzed. The computational results show that the
β″ and
β phases exhibit good stability under pressure, while the
β′ phase is more sensitive to pressure, undergoing lattice constant distortion within a certain pressure range. As the applied force increases, the sequence of aging precipitation is altered.