The molten Fe80P13C7 alloys can achieve a large undercooling up to 320 K by fluxing technique. With the help of fluxing technique, the molten Fe80P13C7 alloys can be solidified at different undercooling （△T） throug...The molten Fe80P13C7 alloys can achieve a large undercooling up to 320 K by fluxing technique. With the help of fluxing technique, the molten Fe80P13C7 alloys can be solidified at different undercooling （△T） through isothermal undercooling experiment It is indicated that the microstructure of the solidified Fe80P133C7 alloy specimens is refined significantly with the increasing undercooling and the grain size is about 20 μm, 10 μm, 200 nm and 70 nm for △T=50 K, 150 K, 250 K and 320 K, respectively The solidification morphologies of the solidified Fe80P13C7 alloy specimens under different undercooling are quite different. When △T=50 K, it presents a traditional solidification microstructure under a undercooling condition, composed of the primary dendrite and anomalous eutectic within the dendrites. When △T=150 K, a cell-like solidification morphology can be found, which can be proposed to be formed based on the nucleation and growth of spinodal decomposition mechanism. When △T=250 K, there is a strong direction of the solidification under an optical micrograph, two zones can be divided, and the microstructure of each zone presents a network which results from a liquid spinodal decomposition. When △T=320 K, the microstructure presents a random network completely. Microhardness test shows that the hardness of the solidified specimens increases with the undercooling.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51061017)the College Research Plan Project of Xinjiang Uyghur Autonomous Region of China(Grant No.XJEDU2010I04)
文摘The molten Fe80P13C7 alloys can achieve a large undercooling up to 320 K by fluxing technique. With the help of fluxing technique, the molten Fe80P13C7 alloys can be solidified at different undercooling （△T） through isothermal undercooling experiment It is indicated that the microstructure of the solidified Fe80P133C7 alloy specimens is refined significantly with the increasing undercooling and the grain size is about 20 μm, 10 μm, 200 nm and 70 nm for △T=50 K, 150 K, 250 K and 320 K, respectively The solidification morphologies of the solidified Fe80P13C7 alloy specimens under different undercooling are quite different. When △T=50 K, it presents a traditional solidification microstructure under a undercooling condition, composed of the primary dendrite and anomalous eutectic within the dendrites. When △T=150 K, a cell-like solidification morphology can be found, which can be proposed to be formed based on the nucleation and growth of spinodal decomposition mechanism. When △T=250 K, there is a strong direction of the solidification under an optical micrograph, two zones can be divided, and the microstructure of each zone presents a network which results from a liquid spinodal decomposition. When △T=320 K, the microstructure presents a random network completely. Microhardness test shows that the hardness of the solidified specimens increases with the undercooling.
