.2024 Aluminum Alloy Sheet Of The Heat Treatment Process And Performance

The 2024 aluminum alloy belongs to the series of Al-Cu-Mg which is a high strength and low proportion deformation alloy. It is widely used in aviation, spaceflight and other military production. In this work, the system of heat treatment process of 2024 is improved. The influence of heat treatment process to microstructure , mechanical properties, fatigue properties and corrosion properties of the 2024 aluminum alloy is discussed by a series of tests and studies.In this work, the heat treatment process of 2024 aluminum alloy is optimized by orthogonal design. The result of tensile test shows that during the heat treatment process, the mechanical properties is notablely influenced by solution temperature, aging temperature and aging time. Factors which affect σb from strong to weak in the following order: solution temperature, aging temperature, aging time, solution time and storage time.The impact factors of σ_0.2 that from major to minor are: aging temperature, solution temperature , aging time, solution time, storage time.Alloy properties are investigated by different heat treatment process, microstructure is analysised by transmission electron microscopy(TEM).It was found that the growth of the solution temperature is conducive to enhancement of the uniformity and the degree of supersaturation of a solid solution, and is a good foudation for the subsequent aging process. Peak strength appears when aging tempreture is 185℃ and aging time is 10 hours, the mixed structure of small and point S" phase + needle S' phase are observed by TEM. Overaging appears when aging tempreture is 190℃ and aging time is 9—10 hours, the strengthened phase grows up, the microstructure is needle S 'phase + a small number of S"phase. The best heat treatment process is: solution tempreture is 498℃, aging tempreture is 185℃ and aging time is 10 hours.The fatigue properties and corrosion resistance on different heat treament process are contrasted.The fatigue properties are improved after the optimization of the heat treatment process, the corrosion resistance is related to the surface treatment of the sample and is not significantly impacted on the heat treatment process.