Coercivity and microstructure of sintered Nd-Fe-B magnets diffused with Pr-Co,Pr-Al,and Pr-Co-Al alloys

The commercial 42 M Nd-Fe-B magnet was treated by grain boundary diffusion(GBD)with Pr_(70)Co_(30)(PC),Pr_(70)Al_(30)(PA)and Pr_(70)Co_(15)Al_(15)(PCA)alloys,respectively.The mechanism of coercivity enhancement in the GBD magnets was investigated.The coercivity was enhanced from 1.63 T to 2.15 T in the PCA GBD magnet,higher than the 1.81 T of the PC GBD magnet and the 2.01 T of the PA GBD magnet.This indicates that the joint addition of Co and Al in the diffusion source can further improve the coercivity.Microstructural investigations show that the coercivity enhancement is mainly attributed to the exchange-decoupling of the GB phases.In the PCA GBD magnet,the wider thin GB phases can be formed and the thin GB phases can still be observed at the diffusion depth of 1500μm due to the combined action of Co and Al.At the same time,the formation of the Pr-rich shell can also be observed,which is helpful for the coercivity enhancement.

ICP-AES法测定钕铁硼镀镍溶液中的杂质元素含量

建立了用电感耦合等离子体发射光谱法(ICP-AES)测定钕铁硼材料镀镍溶液中镉、锰、铬、铜、铁、钙、锌、铝、钴、钕、镨和铈12种杂质元素含量的方法;确定了仪器的最佳工作参数及各元素的分析谱线;通过采用基体匹配和简单的镀液稀释消除了电镀液中大量存在的基体物质对待检测元素测定的光谱干扰。实验结果表明:本方法中12种待测元素线性关系良好,线性相关系数R>0.999,检出限为0.005~0.690μg/mL,精密度和回收率实验结果表明,本方法具有简便、快速、准确的优点,能够满足日常钕铁硼镀镍溶液中杂质元素的快速检测要求。

ICP-AES法测定钕铁硼磁体中的元素含量

建立了钕铁硼合金中镝、铁、镨、钕、钆、钬、铝、硼、铜、钴、镓、铽、铈和锆各元素的电感耦合等离子体发射光谱分析(ICP-AES)方法。采用盐酸(1+1)溶液溶解样品,定容后用ICP-AES检测。为了提高测量准确度,减小基体效应对元素测量的影响,对高含量元素50倍稀释后进行测试,低含量元素则通过基体匹配法进行检测。进行了加标回收实验和精密度实验,各元素的回收率为83%~114%,相对标准偏差0.1%~1.5%,结果表明,该方法满足钕铁硼样品元素含量分析的日常检测要求,具有操作简便、快速、准确度高等特点。

ICP-AES法同时测定镨钕镝铁硼合金中的铝、铜、硼、镍、钴、锰含量

提出了ICP-AES法同时测定镨钕镝铁硼合金中铝、铜、硼、镍、钴、锰元素的分析方法。研究了谱线的选择,考查了基体含量变化、酸度、功率和雾化压力对测定的影响,测定了本方法分析结果的准确度和回收率。结果表明：该方法快速、准确,RSD均小于4%,回收率在94.10%～105.1%之间,与化学分析方法比对试验,分析结果一致。该方法能满足产品生产和质量控制的日常分析要求。