不同冷却速率下钐铁合金的组织演变行为研究

Microstructure Evolution of Sm-Fe Alloy Produced by Rapid Quenching Process at Different Cooling Rates

摘要: 采用含钐30% (质量分数)的钐铁合金作为原料，在高真空电弧熔炼及单辊旋淬一体炉中进行熔炼快淬，通过改变单辊转速，获得不同冷却速率的钐铁合金薄带。利用场发射扫描电子显微镜研究不同冷却速率下钐铁合金的组织演变规律。结果表明：随快淬速率增加，合金中的晶粒尺寸减小，均匀性提高，当单辊转速达超过24.0 m/s时，钐铁合金晶粒平均尺寸减小至500 nm以下。当单辊转速达到36.0 m/s时，可得到晶体与非晶共存的急冷态钐铁合金，合金偏析大幅度减小。

Abstract: A rapidly quenched Sm-Fe alloy ribbons with a nominal chemical composition of 30% Sm (mass fraction) were prepared in a rotating-quenching furnace under different cooling rates. The micro-structure of the ribbons was investigated with field emission scanning electron microscope (FE- SEM). Results indicated that the grain size decreases and the uniformity increases with the increase of cooling rate. The average grain size of Sm-Fe alloy decreased to less than 500 nm when the rate of rotating wheel was up to 24.0 m/s. A Sm-Fe alloy ribbon with the microstructure of crystal and amorphous co-existing was obtained, whose alloy segregation is reduced significantly, when the rate of rotating wheel reaches 36.0 m/s.