惰气熔融-热导法测定钕铁硼永磁材料中的氢

建立惰气熔融-热导法测定钕铁硼永磁材料中氢的分析方法。当氧-氢比例大于50:1时,CO对氢的测定结果产生一定的干扰,加入舒茨试剂可消除此干扰。采用标准坩埚,称样0.05g,熔融功率为2.85 kW,选择高纯镍篮和锡片做助熔剂,钕铁硼中氢释放完全。以普通钢铁参考物质建立氢校准曲线,线性相关系数r～2=0.9999,检出限为0.75μg/g。该法用于钕铁硼样品中氢的测定,测定结果与脉冲熔融飞行时间质谱-气体元素分析仪测定结果基本一致,测定结果的相对标准偏差为1.4%(n=5)。该方法可以准确测定钕铁硼永磁材料中的氢,能满足日常分析的要求。

Determination of Hydrogen in Nd-Fe-B Permanent Magnet Material by Inert Gas Fusion-Thermal Conductivity Method

A inert gas fusion-thermal conductivity method was used for quantitative determination of hydrogen in Nd-Fe-B permanent magnet material. As there was a certain interference for the determination of hydrogen in Nd-Fe-B when oxygen∶hydrogen was more than 50∶1,Schutz reagent was used to eliminate the interference of CO on H. The calibration curve of hydrogen was plotted using reference material of steel （r2=0.999 9）,and the method detection limit was 0.75μg/g. When the method was applied to the determination of hydrogen in Nd-Fe-B samples, the results were basically consistent with those obtained by pulse-heating time of flight mass spectrometric gas elements analyzer. The relative standard deviation of determination results was 1.4%（n=5）. The results showed that this method can quantify hydrogen in Nd-Fe-B permanent magnet material and meet the daily analysis requirements.