The effects of directional solidification parameters and the coupling of directional solidification parameters and alternating electromagnetic fields on separation and enrichment of the C54–TiSi2 phase were investiga...The effects of directional solidification parameters and the coupling of directional solidification parameters and alternating electromagnetic fields on separation and enrichment of the C54–TiSi2 phase were investigated in a directionally solidified hypoeutectic Ti–65 wt.%Si alloy.The results indicated that by increasing the pull-down velocity at a given position within the ingot,the cooling rate,growth rate,and temperature gradient of ingot could be increased.At a pull-down velocity near 5μm/s,the temperature gradient,cooling rate,and growth rate decreased with increasing the thickness of the C54–TiSi2-rich layer.Electromagnetic fields enhanced mass transfer at pull-down velocities of 5,10,15,and 20μm/s,with resulting enriched layer thicknesses of 15,10,10,and 5 mm,respectively.By increasing the percentage of Ti in the Ti–Si alloy from 25 to 35 wt.%,the thickness of the C54–TiSi2-rich layer was increased from 2.5 to 3.3 cm.However,the maximum C54–TiSi2 content obtained experimentally in this layer decreased from 92.06 to 79.49 mass%.展开更多
基金This research was supported by the National Natural Science Foundation of China(No.U1702251)Special Funds of State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization(Grant No.CNMRCUTS1604)+2 种基金the Program for Innovative Research Team in University of Ministry of Education of China(No.IRT_17R48)Key Laboratory of Comprehensive Utilization of Vanadium and Titanium Resources in Sichuan Province(2019FTSZ06)the PhD Fund of Panzhihua University,and Funded by the State Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization.
文摘The effects of directional solidification parameters and the coupling of directional solidification parameters and alternating electromagnetic fields on separation and enrichment of the C54–TiSi2 phase were investigated in a directionally solidified hypoeutectic Ti–65 wt.%Si alloy.The results indicated that by increasing the pull-down velocity at a given position within the ingot,the cooling rate,growth rate,and temperature gradient of ingot could be increased.At a pull-down velocity near 5μm/s,the temperature gradient,cooling rate,and growth rate decreased with increasing the thickness of the C54–TiSi2-rich layer.Electromagnetic fields enhanced mass transfer at pull-down velocities of 5,10,15,and 20μm/s,with resulting enriched layer thicknesses of 15,10,10,and 5 mm,respectively.By increasing the percentage of Ti in the Ti–Si alloy from 25 to 35 wt.%,the thickness of the C54–TiSi2-rich layer was increased from 2.5 to 3.3 cm.However,the maximum C54–TiSi2 content obtained experimentally in this layer decreased from 92.06 to 79.49 mass%.