Coarse-grain-free wrought aluminum alloy as well as preparation method and product thereof

Abstract

The invention provides a coarse-grain-free wrought aluminum alloy as well as a preparation method and a product thereof. In the coarse-grain-free wrought aluminum alloy, dispersed and fine nanoscale precipitated phases are formed in an alloy matrix through Al, V, Mn, Zr, Li, Ti and Hf, and the precipitated phases are good in thermal stability; and grain boundaries and dislocation can be effectively pinned, grain coarsening and re-fining in the extrusion process are restrained, and meanwhile, the matrix strength is improved. The element B can be combined with Ti to effectively refine grains; the element Be can form a compact oxidation film on the surface of molten aluminum to further prevent burning loss of the Al / Mg / Zn / Li element; and meanwhile, the formation of coarse grains can be effectively restrained through a multi-stage homogenization treatment system, on-line water spraying, higher extrusion container temperature and lower extrusion speed. According to the coarse-grain-free wrought aluminum alloy, the coarse grain structure is not observed under low magnification, the tensile strength and the elongation percentage of a center part and an edge part of an extruded bar are basically consistent and can reach 558-592 MPa, the elongation percentage is 13.9-15.1%, and the fatigue life exceeds 107 times.

Description

technical field [0001] The invention belongs to the technical field of metal materials, and relates to a deformed aluminum alloy without coarse grains, a preparation method thereof and products (such as rods, profiles or plates). Background technique [0002] Al-Zn-Mg-Cu series aluminum alloys are a kind of heat-treatable and strengthened ultra-high-strength aluminum alloys. Due to their good ductility, fracture toughness and fatigue properties, they have been widely used in aviation, aerospace, electronics and other fields, especially their rods. Materials, profiles, plates and forgings have been used as aircraft girders, skins, rivets, connecting parts of missile cabins, radar frames, etc. However, as the mobility requirements of my country's weapons and equipment are getting higher and higher, higher requirements are put forward for lightweight materials such as aluminum alloys, especially Al-Zn-Mg-Cu-based rods, profiles and plates. In the middle, coarse grains are easil...

AI Technical Summary

Problems solved by technology

However, as the mobility requirements of my country's weapons and equipment become higher and higher, higher requirements are placed on lightweight materials such as aluminum alloys, especially Al-Zn-Mg-Cu-based rods, profiles and plates. In the medium, it is easy to produce coarse grains, resulting in a significant decrease in the mechanical properties of the material, a significant decrease in tensile strength and elongation, a decrease in fatigue performance, a decrease in corrosion resistance, and uneven material properties.

At the same time, in the subsequent surface treatment process, the surface after anodization is often uneven due to the existence of coarse grains, which seriously affects the performance of the material.

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