差示扫描量热法测试非晶合金居里温度

从坩埚选择、试样称取量、升温速率等方面摸索了差示扫描量热法(DSC)测试非晶材料 Fe78 Si9 B13居里温度的最佳试验条件,分析了不同升温速率对测试结果的影响,同时与该材料晶化温度、In(标准物质)的熔点随升温速率的变化情况进行了对比分析.研究结果表明：该材料的 DSC 曲线上居里转变过程对应的热信号表现为一个抖动.不同条件下测得的居里温度为399~402℃,与 Hall 效应法测试结果基本一致.最佳的试验条件是：Al坩埚、试样称取量6 mg 左右、20 K/min.在升温速率不小于10 K/min 时可以得到居里转变信号,与该材料晶化温度受热滞后影响而明显随升温速率增大而增大的情况不同,由于居里转变过程相变潜热较小,居里温度测试结果基本不受热滞后的影响.

Curie temperature determination of amorphous alloy by differential scanning calorimetry

Determination of Curie temperature of amorphous alloy Fe78 Si9 B1 3 by differential scanning calorimetry was researched from the choices of crucibles,masses of the sample and heating rates,and then the optical test conditions were obtained.The relationship of Curie temperature of amorphous alloy Fe78 Si9 B1 3 with heating rates was analyzed and compared simultaneously with the relationships of crystallization temperatures of Fe78 Si9 B1 3 , melting temperature of In (standard material used for thermal analysis)with the heating rates.The results show that the heat signal of the Curie transition shows a little wave in the DSC curves.The Curie temperature obtained at different test conditions are about from 399 ℃ to 402 ℃,which are equivalent to the results obtained by the methods according to Hall effect.The best conditions are as follows:Al crucibles,mass of about 6 mg,heating rate of 20 K/min.It is found that the Curie signal can be obtained only as heating rates bigger than 10 K/min and the results are not affected obviously by the heating rates when they are increased because of the low heat as no thermal hysteresis affect the results,while the results of crystallization temperatures increase obviously for the thermal hysteresis.