材料科学与工程学院知识库

The microstructure of 6063 aluminum alloy has an important influence on its properties. In this paper, the effect of the composite addition of Nd (0, 0.1 wt%, 0.2 wt%, 0.4 wt%, 0.6 wt%) and Al-Ti-B master alloy on the microstructure and mechanical properties of 6063 aluminum alloy was studied. The results show that the composite modification of rare earth Nd and Al-Ti-B has great refinement effect on 6063 aluminum alloy. With the amount of rare earth Nd is 0.1 wt%, the grain boundary is mainly composite of a short rod or discontinuous granular AlFeSiMgNd complex compound. With the content of rare earth reaches 0.6 wt%, the enrichment of rare earth Nd occurs at the grain boundaries, and a grid-like AlSiNd phase is formed. After 180 days of natural aging on the basis of T6 heat treatment, with the increase in the amount of rare earth Nd added, the elongation of the 6063 aluminum alloy increased significantly, but the tensile strength and vickers hardness decreased. The alloy undergoes ductile fracture, and AlSiNd and AlFeSiMgNd particles are present on the fracture surface. This may also be the main reason for the effect of Nd on the mechanical properties of 6063 alloy. © 2020 The Author(s). Published by IOP Publishing Ltd.