双辊铸轧2060铝锂合金的偏析行为

Segregation Behavior of 2060 Al-Li Alloy during Twin Roll Casting

为探究溶质偏析行为对双辊铸轧Al-Li合金组织和腐蚀行为的影响,成功制备了不同工艺范围下的铝锂合金铸轧板坯,并构建了热-流耦合模型。结合场发射型扫描电子显微镜(SEM),能谱分析仪(EDS),和透射电子显微镜(TEM)探究了不同工艺条件下组织的耐蚀性差异。结果表明:TRC-3高铸轧速条件下的制备出现了显著的宏观偏析现象。通过结合温度和流速的计算,详细分析了这种偏析机制的结果。偏析将遗传到最终的T6状态组织,恶化T_(1)相的析出,并恶化最终的耐腐蚀性能。深入讨论了偏析对腐蚀行为的影响机理,并提出了一种能够实现低偏析、高耐腐蚀性的铸轧铝锂合金工艺。

To investigate the effect of solute segregation behavior on the microstructure and corrosion behavior of Al Li alloy during twin roll casting,aluminum lithium alloy casting and rolling slabs under different process ranges were successfully prepared,and a thermal flow coupling model was constructed.The differences in corrosion resistance of tissues under different process conditions were investigated by combining field emission Scanning Electron Microscopy(SEM),Energy Dispersive Spectroscopy(EDS),and Transmission Electron Microscopy(TEM).The results indicate that there is a significant macroscopic segregation phenomenon in the preparation of TRC-3 under high casting and rolling speed conditions.The results of this segregation mechanism were analyzed in detail by combining temperature and flow rate calculations.Segregation will be inherited into the final T6 state organization,worsening the precipitation of T_(1)phase and deteriorating the final corrosion resistance.The mechanism of the influence of segregation on corrosion behavior was deeply discussed,and a cast rolled aluminum lithium alloy process that can achieve low segregation and high corrosion resistance was proposed.