In this paper, we systematically investigated the microstructure evolution and coercivity mechanism of hydrogenation-disproportionation-desorption-recombination (HDDR) treated Nd-Fe-B strip cast alloys by transmission electron microscopy (TEM) and three-dimensional atom probe (3DAP) analyses. The rod-like NdH_2+x phases with diameters of 10–20 nm are embedded into α-Fe matrix, which hereditarily leads to textured grains in HDDR alloy. The migration of NdH_2+x from Nd-rich region to α-Fe matrix during hydrogen absorption process contributes to the uniform redistribution of Nd-rich phases after HDDR treatment. The HDDR alloy with single domain grain sizes of 200–300 nm exhibits relatively low coercivity of 1.01 T that arises from pinning magnetic domain motion. The weak c-axis orientation of HDDR alloy results in a lower reverse magnetic field (coercivity) to reduce remanence to 0. Moreover, the direct contact of Nd₂Fe₁₄B grains and the high concentration of ferromagnetic elements (Fe content ≈ 66.06 at%, Co content ≈ 0.91 at%) in Nd-rich grain boundary layer lead to strong magnetostatic coupling effect among Nd₂Fe₁₄B grains. The nano-sized α-Fe inside Nd₂Fe₁₄B matrix makes the magnetization reversal easily and decreases the coercivity of HDDR alloy.

在本文中，我们通过透射电子显微镜（TEM）和三维原子探针（3DAP）分析系统研究了氢化-歧化-解吸-复合（HDDR）处理的Nd-Fe-B带铸合金的微观结构演变和矫顽力机制。 . 直径为 10-20 nm的棒状 NdH _{2+ x}相嵌入到 α-Fe 基体中，这在遗传上导致 HDDR 合金中的织构晶粒。NdH _{2+ x的迁移}在吸氢过程中从富Nd区域到α-Fe基体有助于HDDR处理后富Nd相的均匀重新分布。单畴晶粒尺寸为 200-300 nm 的 HDDR 合金表现出相对较低的 1.01 T 矫顽力，这是由钉扎磁畴运动引起的。HDDR合金的弱c轴取向导致较低的反向磁场（矫顽力）将剩磁降低到0。此外，Nd ₂ Fe ₁₄ B晶粒的直接接触和高浓度的铁磁元素（Fe含量≈66.06 at %, Co含量≈0.91 at%)在富Nd晶界层中导致Nd ₂ Fe ₁₄ B晶粒间的强静磁耦合效应。Nd中的纳米级α-Fe₂ Fe ₁₄ B 基体使磁化容易反转，降低HDDR合金的矫顽力。