Researches On Hot Working And Heat Treatment Technology Of High-performance 2124 Aluminium Alloy

2124 aluminum alloy is one kind of al-Cu-Mg alloy based on tranditional 2024 aluminum alloy by reducing iron, silicon and other impurities contents. The alloy has high purity and good comprehensive performance, such as high-strength and high tougness. Hot working and heat treatment are important for the production of this alloy. Nowadays,2124 aluminum alloy is used for the product with larger size, larger cross-section and more complex shape, and higher mechanical performance. The hot working and heat treatment process become more important than ever.Therefore, investigations on the hot working and heat treatment process of 2124 aluminum alloy have important guiding significance.This work studied the hot working process of 2124 aluminum alloy ingot by isothermal simulation experiment. It is found that the rheological behavior of this alloy is closely related to the deformation temperature and strain rate. And constitutive equation for flow stress of this alloy is established. The influence of deformation conditions on microstructure of this alloy is investigated by optical microscope and transmission electron microscopy. The processing map of 2124 aluminum alloy was established based on dynamic material model. It shows that the suitable hot working conditions of 2124 aluminum alloy is at temperature 450～480 ℃ with strain rate of 0.01～0.1s-1, i.e. the region with medium temperature and low strain rate at processing map. When choosing processing technology, it is better to adopt multi-pass and small deformation in order to obtain the larger area of best processing performance.The influence of heat treatment process on properties of 2124 aluminum alloy was investigated by means of solid solution, quenching and aging experiment study. The results show that, enhanced solid solution temperature or prolonged solid solution can increase the dissolution of excess phases in the 2124 aluminum alloy and improve the solid solution degree, thus improving the strength of this alloy. But the excessively high solid solution temperature or long solid solution time can lead to decrease of elongation. The lower quenching temperature is beneficial to tensile strength and yield strength, while the higher quenching temperature is beneficial to elongation. The suitable quenching temperature is 15℃. Prolonged quenching transfer time has little effect on strength of this alloy, but can significantly decrease the elongation. The quenching transfer time shoud be shorten as much as possible. The optimum solid solution and aging treatments for 2124 alluminum alloy are 490 ℃/80 min and 185℃/12 h, respectively. With these solid solution and aging treatments, tensile strength, yield strength and elongation of this alloy are 94 MPa,464MPa and 8%.