Papers by Keyword: 7A04 Aluminium Alloy

Abstract: The marine atmospheric environment spectrum of Xisha was compiled by using the environmental data of Xisha atmosphere test station. The determination method of the parameters of every process and the equivalent relationship between the accelerated spectrum and the actual use environment were presented by the equivalent conversion method. The accelerated corrosion test methods were composed of ultraviolet radiation and periodic soakage, and carried out verification tests of indoor and outdoor corrosion. The accelerated corrosion test methods provide a reference for the study on corrosion behavior of 7A04 aluminum alloy in the typical oceanic and atmospheric environment of Xisha.

Abstract: By using cryogenic treatment on 7A04 aluminum alloy tested with micrographic analysis and mechanical properties test, we studied the impact on mechanical properties of 7A04 aluminum alloy The results showed that the strength of 7A04 aluminum alloy could be highly increased and the grain size would be reduced in the process through being treated in 480°C/80min + aging in 120°C/4h + cryogenic treatment + aging at 120°C/16h.7A04 aluminum alloy are more fully recrystallized to grain refinement and the tensile strength of it can be increased to 720Mpa after the treatment.

Abstract: Aiming at traditional peak aging of 7A04 Aluminum Alloy with high strength but low corrosion resistance, innovative gradually cooling three-step aging heat treatment process were designed, conventional mechanical properties and corrosion resistance of 7A04 aluminum after three kinds of aging treatments was studied through microstructure. The results show that compared with the traditional peak aging process, two gradually cooling three-step aging process is to improve materials tensile strength, plastic and impact toughness in different degrees. Meanwhile corrosion resistance of materials has improved significantly. And extension of low temperature aging time is conducive to the further improvement of strength.

Abstract: The mechanical properties of a 7A04 aluminum alloy were improved by deformation strengthening and phase transformations strengthening adopting thermomechanical treatment, whose process include solution treatment, deformation treatment and ageing treatment in turn. The paper focuses on the influences of deforming degree and ageing process on microstructure and properties of 7A04 aluminum alloy. The experimental results show that hardness increased with increasing deformation ratio, and the value are greatly higher than that of samples after solution treatment. The results of ageing after deformation show that the hardness enhanced with prolonging the ageing time, which reach the peak value at 16 hours. In addition, the microstructure became more homogeneous and the grain was refined obviously by metallography microscope observation. The second phase precipitate dispersedly to strengthen the alloy. Above all, in order to obtain the better mechanical properties, the optimal thermomechanical treatment processes are solution treatment at 470°C for 2h, deformation with ratio of 40% as well as ageing at 120°C for 16h.