Sintered permanent magnets based on domain-wall-pinning-type Sm₂Co₁₇ have recently attracted considerable attention due to their low-temperature coefficient, excellent high-temperature magnetic properties, and remarkable oxidation and corrosion resistances. However, the relationship between the knee-point coercivity, $H_{\mathrm {k}}$ , and the microstructures of these Sm₂Co₁₇-based bulk magnets has not been widely studied. Therefore, herein, sintered permanent magnets with nominal compositions of Sm(Co_balFe_0.227Cu_0.070Zr_0.023)_z ( $z =7.40$ , 7.47, 7.54, 7.61, and 7.84) (at.%) were prepared via conventional powder metallurgy, and their magnetic properties were investigated. The results showed that as $z$ increased from 7.40 to 7.84, $H_{\mathrm {k}}$ first increased and then decreased. The maximum optimal $H_{\mathrm {k}}$ of 1717 kA $\cdot \text{m}^{-1}$ (21.58 kOe) corresponded to the magnet with dimensions of ~52.8 mm $\times49.2$ mm $\times36.6$ mm, a maximum magnetic energy product (BH)_max of 232 kJ $\cdot \text{m}^{-3}$ (29.1 MG $\cdot $ Oe), and $z =7.61$ . The transmission electron microscopy revealed that the crystalline structure and chemical composition of the magnet are the two main factors determining $H_{\mathrm {k}}$ .

中文翻译：

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高拐点矫顽力 Hk 烧结 Sm2Co17 合金的磁性能和显微组织

基于畴壁钉扎型Sm ₂ Co _{17 的}烧结永磁体由于其低温度系数、优异的高温磁性能以及显着的抗氧化和耐腐蚀性，近年来引起了广泛关注。然而，膝点矫顽力之间的关系， $H_{\mathrm {k}}$ ，而这些 Sm ₂ Co ₁₇基块状磁铁的微观结构尚未得到广泛研究。因此，在此，标称成分为 Sm(Co _bal Fe _0.227 Cu _0.070 Zr _0.023 ) 的烧结永磁体_z ( $z = 7.40$ 、7.47、7.54、7.61 和 7.84) (at.%) 通过常规粉末冶金制备，并研究了它们的磁性能。结果表明，作为 $z$ 从 7.40 增加到 7.84， $H_{\mathrm {k}}$ 先增加后减少。最大最优 $H_{\mathrm {k}}$ 1717 kA $\cdot \text{m}^{-1}$ (21.58 kOe) 对应于尺寸为 ~52.8 mm 的磁铁 $\times49.2$ 毫米 $\times36.6$ mm，最大磁能积（波黑)_最大232 kJ $\cdot \text{m}^{-3}$ (29.1 MG $\cdot $ Oe)，和 $z =7.61$ . 透射电子显微镜显示，磁铁的晶体结构和化学成分是决定磁铁的两个主要因素。 $H_{\mathrm {k}}$ .