Anisotropy of microstructure and properties of high strength hot-extruded processed aluminum alloy

Abstract

The microstructure and properties of high strength aluminum alloy under extrusion—hot pressing—solid solution-aging treatment were studied by XRD analysis, hardness and conductivity test, tensile test, intergranular corrosion and exfoliation corrosion test. At the same time, the influence of hot compression technology on the properties of the compressed surface was investigated. The results show that there is anisotropy between the properties of aluminum extrusion-hot pressed material, the hardness and conductivity in the Z direction are higher than those in the X and Y directions, and the tensile strength and plasticity are better than those in the Y direction, among which the strength is increased by about 122 MPa and the elongation by about 6.17%. The corrosion resistance also exists in the anisotropy, in which the Z direction has the best intergranular corrosion resistance and the corrosion depth is 167.46 um, the Y direction has the best exfoliation corrosion resistance and the grade reaches PC grade. The thermal compression process is beneficial to improve the plasticity, electrical conductivity and exfoliation corrosion performance of the compressible surface material, but reduces the hardness, tensile strength and inter-granular corrosion performance.