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在落管自由落体条件下实现了Fe-48.8％Sn偏晶、Fe-40％Sn亚偏晶和Fe.58％Sn过偏晶合金的快速凝固.对于直径范围在100-1000μm的Fe-48.8％Sn,Fe-40％Sn和Fe-58％Sn合金液滴,最大过冷度分别为270,282和288 K.液滴直径较小时,Fe-48.8％Sn偏晶合金的微观结构呈现出均匀弥散分布的组织,当液滴中分散相直径为6μm,过冷度为30 K时,Marangoni迁移速率比Stokes运动速率快37倍.对于Fe-40％Sn亚偏晶,当液滴直径从1000减小为100μm时,其生长形态从柱状α-Fe枝晶分布在富Sn相基底上转变为α-Fe颗粒分布在富Sn相基底上,α-Fe枝晶的生长速度从0.45增大到4.65 m／s.对于Fe-58.8％Sn过偏晶合金,初生相α-Fe枝晶的晶粒尺寸随过冷度的增加显著减小.
Fe-48.8% Sn crystallite, Fe-40% Sn sub-crystallite and Fe.58% Sn orthorhombic alloy were rapidly solidified under the free fall tube-falling condition.For the Fe-48.8 with a diameter in the range of 100-1000μm, % Sn, Fe-40% Sn and Fe-58% Sn alloy droplets, the maximum undercooling was 270, 282 and 288 K. Microscopic structure of Fe-48.8% Sn monotectic alloy showed uniform dispersion when the droplet diameter was small Distribution, the migration rate of Marangoni is 37 times faster than that of Stokes when the dispersed phase diameter is 6μm and the undercooling degree is 30 K. For Fe-40% Sn sub-crystallite, when the droplet diameter is reduced from 1000 When the size is 100μm, the growth morphology changes from columnar α-Fe dendrites on the Sn-rich phase to α-Fe particles on the Sn-rich phase. The growth rate of α-Fe dendrites increases from 0.45 to 4.65 m / s. For the Fe-58.8% Sn over-crystallite alloy, the grain size of α-Fe dendrites in primary phase decreases with the increase of undercooling.