Assuming that intergranular phase (IP) existing between adjacent grains is a weak magnetic phase, we study the effect of IP on the coercivity in the HDDR Nd-Fe-B magnet. The results indicate that the coercivity increa...Assuming that intergranular phase (IP) existing between adjacent grains is a weak magnetic phase, we study the effect of IP on the coercivity in the HDDR Nd-Fe-B magnet. The results indicate that the coercivity increases with the increasing IP’s thickness d, but decreases with increasing its anisotropy constant K1(0). When the structure defect thickness r0 =6nm, d=1nm and K1(0)=0.15K1 (K1 is the normal anisotropy constant in the inner part of a grain), our calculated coercivity is in agreement with available experimental data.展开更多
A new nanostructured ZrB_(2)-ZrC composite coating with ZrB_(2)-ZrC nanoscale eutectic and ZrB2+Amorphous microstructure was synthesized in situ by plasma spraying Zr-B4 C-Al composite powder.The thermal analysis,quen...A new nanostructured ZrB_(2)-ZrC composite coating with ZrB_(2)-ZrC nanoscale eutectic and ZrB2+Amorphous microstructure was synthesized in situ by plasma spraying Zr-B4 C-Al composite powder.The thermal analysis,quenching experiments and microstructure characterization were investigated and the formation mechanism of the bimodal in-situ microstructure was revealed.Al contributed to the liquid phase separation of molten droplets,which is the key to forming ZrB2+Amorphous microstructure.The formation of coating followed reaction-melting-liquid separation-deposition and solidification mechanism.The nanostructured ZrB_(2)-ZrC composite coating with Al-O intergranular amorphous phase has excellent mechanical properties.The uniform nano-grains improved the hardness and the toughness of the ZrB_(2)-ZrC eutectic.The ZrB_(2)+Al-O amorphous microstructure obtained high toughness and the toughening mechanism was the crack deflection and crack branching caused by intergranular Al-O amorphous phase.展开更多
The FeZrB amorphous alloys for simulating the intergranular amorphous phase in the nanocrystalline Fe 89 Zr 7B 4 soft magnetic materials were obtained by mechanical alloying of a mixture of elemental Fe, Zr and ...The FeZrB amorphous alloys for simulating the intergranular amorphous phase in the nanocrystalline Fe 89 Zr 7B 4 soft magnetic materials were obtained by mechanical alloying of a mixture of elemental Fe, Zr and B powders for 25 h. It is shown that the Curie temperature of the simulated intergranular phase alloy is much lower than that of the intergranular phase with the same chemical composition in the nanocrystalline Fe 89 Zr 7B 4 alloy. The possible mechanism is mainly due to the strong ferromagnetic exchange force among the nanocrystalline α Fe grains.展开更多
用在谷物边界的建议不同 anisotropy 表情 K <sub>1</sub>′(r) 和 K <sub>1</sub>″(r) ，我们调查效果内部平均 anisotropy 〈K <sub>1</sub>〉 上的小粒...用在谷物边界的建议不同 anisotropy 表情 K <sub>1</sub>′(r) 和 K <sub>1</sub>″(r) ，我们调查效果内部平均 anisotropy 〈K <sub>1</sub>〉 上的小粒的阶段(IP )谷物边界和 coercivity H <sub > HDDR (加氢， disproportionation，解吸附作用和再结合) 的 c </sub> Nd-Fe-B 结合了磁铁。当 IP 的厚度 d 是零时，结果显示那， 〈K <sub>1</sub>〉并且 H <sub > c </sub> 基于 K <sub>1</sub>″(r) 基于 K <sub>1</sub>′(r) 等于相应的。当 d 拿非零价值时， 〈K <sub>1</sub>〉并且 H <sub > 分别地， c </sub> 与增加 d 更快基于 K <sub>1</sub>″(r) 掉落并且升起。当 d 是 1 nm，结构缺点厚度 r <sub>0</sub> 接近域墙(∼4 nm ) 的厚度时，计算 coercivity 与 avaiable 一致很好试验性的数据。展开更多
文摘Assuming that intergranular phase (IP) existing between adjacent grains is a weak magnetic phase, we study the effect of IP on the coercivity in the HDDR Nd-Fe-B magnet. The results indicate that the coercivity increases with the increasing IP’s thickness d, but decreases with increasing its anisotropy constant K1(0). When the structure defect thickness r0 =6nm, d=1nm and K1(0)=0.15K1 (K1 is the normal anisotropy constant in the inner part of a grain), our calculated coercivity is in agreement with available experimental data.
基金supports of the National Natural Science Foundation of China(Nos.52371063 and 52072110)the Natural Science Foundation of Hebei Province(No.E2018202034)the Central Funds Guiding the Local Science and Technology Development of Hebei Province(No.236Z7610G).
文摘A new nanostructured ZrB_(2)-ZrC composite coating with ZrB_(2)-ZrC nanoscale eutectic and ZrB2+Amorphous microstructure was synthesized in situ by plasma spraying Zr-B4 C-Al composite powder.The thermal analysis,quenching experiments and microstructure characterization were investigated and the formation mechanism of the bimodal in-situ microstructure was revealed.Al contributed to the liquid phase separation of molten droplets,which is the key to forming ZrB2+Amorphous microstructure.The formation of coating followed reaction-melting-liquid separation-deposition and solidification mechanism.The nanostructured ZrB_(2)-ZrC composite coating with Al-O intergranular amorphous phase has excellent mechanical properties.The uniform nano-grains improved the hardness and the toughness of the ZrB_(2)-ZrC eutectic.The ZrB_(2)+Al-O amorphous microstructure obtained high toughness and the toughening mechanism was the crack deflection and crack branching caused by intergranular Al-O amorphous phase.
文摘The FeZrB amorphous alloys for simulating the intergranular amorphous phase in the nanocrystalline Fe 89 Zr 7B 4 soft magnetic materials were obtained by mechanical alloying of a mixture of elemental Fe, Zr and B powders for 25 h. It is shown that the Curie temperature of the simulated intergranular phase alloy is much lower than that of the intergranular phase with the same chemical composition in the nanocrystalline Fe 89 Zr 7B 4 alloy. The possible mechanism is mainly due to the strong ferromagnetic exchange force among the nanocrystalline α Fe grains.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 50671055, 50801043)
文摘用在谷物边界的建议不同 anisotropy 表情 K <sub>1</sub>′(r) 和 K <sub>1</sub>″(r) ，我们调查效果内部平均 anisotropy 〈K <sub>1</sub>〉 上的小粒的阶段(IP )谷物边界和 coercivity H <sub > HDDR (加氢， disproportionation，解吸附作用和再结合) 的 c </sub> Nd-Fe-B 结合了磁铁。当 IP 的厚度 d 是零时，结果显示那， 〈K <sub>1</sub>〉并且 H <sub > c </sub> 基于 K <sub>1</sub>″(r) 基于 K <sub>1</sub>′(r) 等于相应的。当 d 拿非零价值时， 〈K <sub>1</sub>〉并且 H <sub > 分别地， c </sub> 与增加 d 更快基于 K <sub>1</sub>″(r) 掉落并且升起。当 d 是 1 nm，结构缺点厚度 r <sub>0</sub> 接近域墙(∼4 nm ) 的厚度时，计算 coercivity 与 avaiable 一致很好试验性的数据。
