二次HDDR工艺制备的高矫顽力各向异性钕铁硼磁粉

采用二次HDDR工艺(简称"t-HDDR工艺")制备了高矫顽力各向异性钕铁硼磁粉。研究了化学成分和工艺参数对磁粉性能的影响。结果表明:t-HDDR工艺对于化学成分为RxTbalByMz的磁粉均适用;稀土元素R(Pr、Nd、Dy等)与低熔点添加元素M(Ga、Cu、Al等)含量越多,t-HDDR工艺对磁粉矫顽力的提升幅度越大;在t-HDDR工艺的首次HDDR工艺中,实施"完全脱氢"工序,可以最大限度地提升磁粉的矫顽力;相对于常规的单次HDDR工艺,t-HDDR工艺可使RxTbalByMz系各向异性钕铁硼磁粉的矫顽力Hci提高160~320k A/m(2~4k Oe)。t-HDDR工艺操作简便、原材料成本低,所生产的磁粉不仅矫顽力高,而且剩磁与最大磁能积也相对较高。

High coercivity anisotropic Nd-Fe-B magnetic powder prepared by twice HDDR process

In this study, high coercivity anisotropic Nd-Fe-B magnetic powders were prepared by twice HDDR process (hereinafter referred to as "t-HDDR process"). The effects of chemical composition and process parameters on the performance of magnetic powders were studied.The results show that t-HDDR process is applicable to chemical composition for RxT1-x-y-zByMz magnetic powder. The higher the content of rare earth elements R (Pr, Nd, Dy, etc.) and low melting point elements M (Ga, Cu, Al, etc.) , the higher coercivity increasing of Nd-Fe-B magnetic powders. In the first HDDR process of t-HDDR process, complete dehydrogenation process can maximize the coercivity. Compared to the conventional single HDDR process, t-HDDR process can make the coercivity of magnetic powders increased by 160~320 kA/m (2~4 kOe). t-HDDR process is easy to operate and the cost of raw material is low. The anisotropic Nd-Fe-B magnetic powders prepared by t-HDDR process have not only higher coercivity, but also relatively higher remanence and maximum magnetic energy product.