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采用落管无容器处理技术实现了Ti_(61.2)Cu_(32.5)Fe_(6.3)三元包共晶合金在自由落体条件下的快速凝固,获得了直径为80—1120μm液滴的凝固组织.实验中获得的过冷度范围为34—293 K,最大过冷度达0.23T_L.研究发现,在自由落体条件下,由于受到无容器、微重力、超高真空等因素的影响,合金熔体的凝固组织中包含Cu_(0.8)Fe_(0.2)Ti相、CuTi_2相和CuT_3相,显著偏离了平衡状态.Cu_(0.8)Fe_(0.2)Ti为初生相,同时又与CuTi_2相形成两相共晶;CuTi_3相则呈现枝晶形貌,并发生了明显的溶质截留效应.随着过冷度的增大,共晶组织由层片共晶向不规则共晶转变,形貌由长条状共晶团变为椭球状共晶团,最终变为球状共晶胞;Cu_(0.8)Fe_(0.2)Ti相枝晶形貌由粗大枝晶变为碎断枝晶,进一步变成不规则的粒状晶粒;CuTi_3相枝晶则由碎块状转变为完整枝晶.
The rapid solidification of Ti_ (61.2) Cu_ (32.5) Fe_ (6.3) eutectic alloy eutectic alloy under free-fall condition was achieved by the tubeless vessel-free processing technique, and the solidified structure of 80-1120μm diameter droplets was obtained. In the range of 34-293 K, the maximum undercooling of 0.23T_L. The study found that under free fall conditions, due to container-free, microgravity, ultra-high vacuum and other factors, the alloy melt The solidified structure contains Cu_ (0.8) Fe_ (0.2) Ti phase, CuTi_2 phase and CuT_3 phase, which deviate significantly from the equilibrium state.Cu_ (0.8) Fe_ (0.2) Ti is the primary phase and simultaneously forms two phase eutectic with CuTi_2 phase While the CuTi 3 phase shows a dendritic morphology with obvious solute interception effect. With the increase of undercooling, the eutectic structure changes from eutectic to irregular eutectic, The eutectic grains became ellipsoidal eutectic and finally became spherical eutectic. The dendritic morphology of Cu 0.8 Fe 0.2 Ti transformed from coarse dendrites to broken dendrites and became irregular granular Grains; CuTi_3 phase dendrite from broken into complete dendrite.