Hu Dao-Chun, Wang Lei, Wang Hong-Jun
Engineering Technology Training Center, Nanjing Institute of Industry Technology, Nanjing 210023, China.
Jiangsu Research and Development Center of Precision Manufacturing, Nanjing 210023, China.
Materials (Basel). 2020 Feb 26;13(5):1042. doi: 10.3390/ma13051042.
Multiple hot-compression tests were carried out on the 6082 aluminum (Al) alloy using a Gleeble-1500 thermal simulation testing machine. Data on flow stresses of the 6082 Al alloy at deformation temperatures of 623 to 773 K and strain rates from 0.01 to 5 s were attained. Utilizing electron backscatter diffraction (EBSD) and a transmission electron microscope (TEM), the dynamic recrystallization behaviors of the 6082 Al alloy during hot compression in isothermal conditions were explored. With the test data, a hot-working processing map for the 6082 Al alloy (based on dynamic material modeling (DMM)) was drawn. Using the work-hardening rate, the initial critical strain causing dynamic recrystallization was determined, and an equation for the critical strain was constructed. A dynamic model for the dynamic recrystallization of the 6082 Al alloy was established using analyses and test results from the EBSD. The results showed that the safe processing zone (with a high efficiency of power dissipation) mainly corresponded to a zone with deformation temperatures of 703 to 763 K and strain rates of 0.1 to 0.3 s. The alloy was mainly subjected to continuous dynamic recrystallization in the formation of the zone. According to the hot-working processing map and an analysis of the microstructures, it is advised that the following technological parameters be selected for the 6082 Al alloy during hot-forming: a range of temperatures between 713 and 753 K and strain rates between 0.1 and 0.2 s.
使用Gleeble-1500热模拟试验机对6082铝合金进行了多次热压缩试验。获得了6082铝合金在623至773 K变形温度和0.01至5 s应变率下的流变应力数据。利用电子背散射衍射(EBSD)和透射电子显微镜(TEM),研究了6082铝合金在等温条件下热压缩过程中的动态再结晶行为。根据试验数据,绘制了6082铝合金的热加工工艺图(基于动态材料模型(DMM))。利用加工硬化率,确定了引起动态再结晶的初始临界应变,并构建了临界应变方程。利用EBSD的分析和测试结果,建立了6082铝合金动态再结晶的动力学模型。结果表明,安全加工区(具有较高的功率耗散效率)主要对应于变形温度为703至763 K、应变率为0.1至0.3 s的区域。在该区域形成过程中,合金主要发生连续动态再结晶。根据热加工工艺图和微观组织分析,建议6082铝合金在热成型过程中选择以下工艺参数:温度范围为713至753 K,应变率为0.1至0.2 s。