二次HDDR工艺制备的高矫顽力各向异性钕铁硼磁粉

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

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160~320kA/m（2~4kOe）。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。

In this study,high coercivity anisotropic Nd-Fe-B magnetic powders were prepared by twice HDDRprocess(hereinafter referred to as"t-HDDR process").The effects of chemical composition and process parameters onthe performance of magnetic powders were studied.The results show that t-HDDR process is applicable to chemicalcomposition for RxT1-x-y-zByMz magnetic powder.The higher the content of rare earth elements R(Pr,Nd,Dy,etc.)andlow melting point elements M(Ga,Cu,Al,etc.),the higher coercivity increasing of Nd-Fe-B magnetic powders.In thefirst HDDR process of t-HDDR process,complete dehydrogenation process can maximize the coercivity.Compared tothe conventional single HDDR process,t-HDDR process can make the coercivity of magnetic powders increased by160~320kA/m(2~4kOe).t-HDDR process is easy to operate and the cost of raw material is low.The anisotropicNd-Fe-B magnetic powders prepared by t-HDDR process have not only higher coercivity,but also relatively higherremanence and maximum magnetic energy product.