脉冲熔融-热导法测定钕铁硼中氮

Determination of Nitrogen in Nd-Fe-B by Pulse Melting Thermal Conductivity Method

钕铁硼中氮的单一测定没有标准方法和相应的参考物质,本文采用钢铁材料氮参考物质建立校准曲线,采用镍篮助熔和自动分析模式测定,建立了脉冲熔融-热导法测定钕铁硼中氮的分析方法。对比了坩埚类型、称样量、熔融功率、样品状态等分析条件对实验结果的影响。结果表明,采用高纯石墨套坩埚、0.1 g样品、熔融功率5.0 kW时,钕铁硼中氮释放完全、测试结果稳定。将本方法用于2种钕铁硼样品中氮的测定,相对标准偏差分别为0.85%、0.97%,加标回收率为94%～104%,且与化学法基本一致。

There were no standard method and corresponding reference material for the determination of nitrogen in Nd - Fe - B. The calibration curve of nitrogen was plotted using reference material of steel. The determination method of nitrogen in Nd - Fe - B alloy by pulse melting - thermal conductivity method was established using nickel basket fluxing - automatic analysis mode. The influences of three analysis conditions including crucible type, different weight, power, and sample state on the determination were compared. The results showed that when high temperature sleeve crucible, 0. 1 g weight and 5.0 kW power were used to determine the nitrogen in Nd - Fe - B, the release of nitrogen was complete and the measurement results were stable. The proposed method was applied to the determination of nitrogen in two types of Nd - Fe - B samples with recoveries of 94% - 104%, and the relative standard deviations （ RSD, n = 5 ） of measurement results were 0. 85% and 0. 97% , respectively. The results were basically accordance with the chemical method.