Study on the mechanism of coarse grain formation of 6061 aluminium alloy forged wheels

Abstract

The formation of coarse grains is easy to occur during the mass production of 6061 aluminium alloy forged wheels. The coarse grains and uneven grain structure will lead to the reduction and instability of the mechanical properties of the wheels, which will affect the fatigue strength, corrosion resistance and impact toughness of the wheels. In this paper, the effect of solution temperature and solution time on the coarse-grained formation of 6061 forged wheel was studied. The reasons and mechanism of coarse-grained formation were revealed by advanced materials characterization techniques such as scanning electron microscope, electron backscattering diffraction and transmission electron microscope. The results show that the deformation causes a large number of dislocation pile-up and entanglement in the grain, forming a large number of small angle sub-grains, and the heating process of sub-grains has more interfaces, which provides the driving energy for the abnormal grain growth.