粉体特性对Sm(Co,Fe,Cu,Zr)_(6.9)高温永磁合金磁性能的影响

Effect of Powder Morphology and Size on Magnetic Properties of High-Temperature Sm(Co,Fe,Cu,Zr)_(6.9) Alloys

分别采用球磨和气流磨工艺制备了Sm(Co,Fe,Cu,Zr)6.9合金粉体。研究了粉体的形状和粒径对烧结磁体磁性能的影响规律。与球磨工艺相比,气流磨制备的粉体颗粒外形更规则。在平均粒径相同的情况下,采用气流磨粉体烧结时效后的永磁合金样品取向度更高,室温剩余磁化强度Mr、最大磁能积(BH)max和500℃条件下的Mr,iHc,(BH)max均优于采用球磨粉体经相同工艺制得的样品。外形规则的气流磨粉体制得的合金样品在室温和500℃条件下的磁性能均随粉体粒径减小呈先升高后降低的趋势,室温下6.8μm气流磨粉体烧结时效样品的磁性能达到最优,为Mr=8092 Gs,iHc=18.3 kOe,(BH)max=123 kJ.m-3;该样品在500℃条件下的磁性能仍达到Mr=5177 Gs,iHc=9.0 kOe,(BH)max=39 kJ.m-3。

The Sm （ Co, Fe, Cu, Zr） 6.9 powders were prepared by ball milling and jet milling, respectively. The effect of powder morphology and size on the magnetic properties of the permanent magnets was investigated. The powders prepared by jet milling were more regular than those produced by ball milling. The magnets sintered and aged from jet-milling powders had superior remnant magnetization Mr, maximum product energy （BH）max at room temperature and Mr, iHo, （BH） max at 500 ℃ than those prepared from the ballmilling powders with the same average size. The magnetic properties of the samples produced from the jetmilling powders increased initially and then decreased as the powder size decreased. The best magnetic properties of Mr = 8092 Gs, iHc = 18.3 kOe, （BH） max = 123 kJ·m^-3 at room temperature was obtained in the samples sintered from the 6.8 μm jet-milling powders, and it still showed magnetic properties of Mr = 5177 Gs, iHc =9.0 kOe, （BH）max= =39 kJ·m^-3 at 500 ℃.