Study On Effect Of Rare-earth On The Microstructure And Property Of3105Aluminum Alloy Sheet By Roll-Casting

3105alloy belongs to Al-Mn-Mg aluminum alloy, which is not reinforced by heat treatment, have high strength and good corrosion resistance. It was widely used in roofing, metope and interior decoration. Hot rolling is the traditional method to produce3105aluminum alloy plate, but its equipment investment is big and production costs are high. The most economic technology to manufactured aluminum alloy is the continuous roll-casting, which has advantages of energy conservation, environmental protection, small investment, low production cost and so on. In this paper, the effect of mixed rare-earth on the microstructure and property of3105is studied, which provide theoretical instructions for3105aluminum alloy production.By studying the effect of rare-earth on the microstructure evolution law and property change of3105aluminum alloy sheet, the following conclusions are obtained:(1) The microstructure of conventional roll-casting of3105aluminum alloy plate is similar to casting microstructure characteristics, it has a strong directional crystallization characteristics, developed dendrite and the microstructure of central is tiny than that of the edge.(2) Compared with conventional microstructure, the microstructure of3105aluminum alloy is not obviously effected when only0.05%rare-earth is added, But,when0.15%rare-earth is added, the microstructure is obviously changed, dendrites space distance reduced, grain is equiaxied, new dispersion phase appears and it results to increase strength of the alloy. Adding0.5%rare-earth in3105aluminum alloy, the microstructure is refined more obvious, coarse dendrite almost disappear, equiaxed microstructure increases, and the dispersion phase is uniformly distributed, the alloy was further strengthened.(3) The grains of3105aluminum alloy is elongated after cold rolling, and the rare-earth has no obviously effect on the microstructure. The microstructure of cold rolled sheet is not obvious changed by stress annealing.(4) Rare-earth is helpful to improve mechanical properties of3105aluminum alloy plates. The tensile strength of3105aluminum alloy without rare-earth is about195.5MPa, it can reach315MPa through adding Rare-earth in the alloy. The tensile fracture of plate belongs to ductile fracture, which morphology is dimple. As the increase of the content of Rare-earth, the dimple becomes small and shallow, plasticity slightly decreases.