Influence of Thermal Deformation Parameters on Mechanical Properties and Microstructure Evolution of AA7075 Aluminum Alloy during Hot Stamping-Quenching Process
Influence of Thermal Deformation Parameters on Mechanical Properties and Microstructure Evolution of AA7075 Aluminum Alloy during Hot Stamping-Quenching Process
复制标题
热变形参数对AA7075铝合金热冲压-淬火过程力学性能及组织演变的影响
DOI：
10.1007/s11837-019-03846-5
复制
发表时间：
2019-11-12
期刊：
影响因子：
2.6
通讯作者：
Sun, Qian
中科院分区：
文献类型：
--
作者：
Li, Huanhuan;Hu, Zhili;Sun, Qian
对AA 7075铝合金进行了热拉伸试验，研究了温度和应变速率对其热冲压-淬火变形行为的影响。相应的机械性能和相关的显微组织也进行了研究。结果表明，流变行为曲线表现为加工硬化，动态平衡，然后急剧下降，最终导致断裂。在较低的变形温度和应变速率下，可获得30%以上的塑性。由于高温下晶界强度减弱，断裂机制由韧性穿晶断裂转变为韧性沿晶断裂。人工时效后试样的强度随固溶热处理后变形温度的升高而提高。对于AA 7075铝合金零件来说，选择400 ℃的温度和0.1-1 s-1的应变速率是比较合适的，以便在此过程中同时获得所需的延展性和最终强度。
Hot tensile tests have been performed on AA7075 aluminum alloy to investigate the effects of temperature and strain rate on its deformation behavior during the hot stamping-quenching process. The corresponding mechanical properties and associated microstructures have also been studied. The results indicate that the flow behavior curves exhibit work hardening, a dynamic equilibrium, then a dramatic decrease, ultimately leading to fracture. Ductility of over 30% can be obtained at relatively low deformation temperature and strain rate. The fracture mechanism changes from ductile transgranular fracture to ductile intergranular fracture owing to the weakening of the grain-boundary strength at high temperatures. The strength of the tested samples after artificial aging treatment increases with the deformation temperature after solid-solution heat treatment. It is more appropriate to choose a temperature of 400°C and a strain rate of 0.1–1 s−1for AA7075 aluminum alloy parts to simultaneously obtain the desired ductility and final strength in this process.