高温稀土永磁合金Sm_2(Co,Cu,Fe,Zr)_(17)

High temperature Sm_2(Co,Cu,Fe,Zr)_(17) permanent magnets

利用粉末冶金的方法研制了 3种成分为Sm (CobalFe0 .2 4Cu0 .0 8Zr0 .0 2 7) 7.0 ,Sm (CobalFe0 .2 7Cu0 .0 5Zr0 .0 2 7) 7.0 ,Sm(CobalFe0 .2 6Cu0 .0 5Zr0 .0 2 6) 7.0 的高温永磁合金 ,并对其磁性能、温度稳定性和显微结构进行了分析 .研究结果表明 :常温时 ,3种永磁合金都具有较高的磁性能 ,其中 ,合金样品Sm (CobalFe0 .2 7Cu0 .0 5Zr0 .0 2 7) 7.0 的内禀矫顽力 (2 16 5 .6kA·m- 1 )和磁能积 (2 12 .0kA·m- 3 )最大 ;2 0 0℃时 ,3种合金的磁性能降低 ,但仍具有较大值 ;增加Co和Fe的含量 ,可提高材料的剩磁 ,当Zr的含量较大时 ,合金的矫顽力较高 ;3种磁体的温度系数都较低 ,最高使用温度均在 40 0℃以上 ,大大高于一般商用磁体的使用温度 ;增加Sm ,Co ,Cu的含量和减少Fe的含量可以提高材料的温度稳定性 ;合金中含有Sm2 (Co,Fe) 1 7主相、Sm(Co,Cu) 5相、Zr的化合物等 ;Sm(Co,Cu) 5相、单质Zr、晶粒边界等钉扎畴壁 ,使合金具有较高的矫顽力 .

Three high temperature magnets, including Sm(Co bal Fe 0.24 Cu 0.08 Zr 0.027 ) 7.0 , Sm(Co bal Fe 0.27 Cu 0.05 Zr 0.027 ) 7.0 and Sm(Co bal Fe 0.26 Cu 0.05 Zr 0.026 ) 7.0 , are produced by powder metallurgy techniques. The magnetic properties, temperature stability and microstructure are analyzed in this article. The results show that Sm(Co bal Fe 0.27 Cu 0.05 Zr 0.027 ) 7.0 has a highest intrinsic coercive force of 2 165.6 kA·m -1 , and a maximum energy product of 212.0 kA·m -3 . The three alloys have low temperature coefficients of coercivity, and the maximum operating temperatures of the three magnets all exceed 400 ℃, which are greatly higher than those of the commercial Sm 2Co 17 alloys. Thermal stability can be improved by applying higher content of Sm, Co, Cu and lower content of Fe. Through the analysis of microstructure, we found that Sm 2(Co,Fe) 17 main phase, Sm(Co,Cu) 5 phase, Zr rich compound and Zr in the alloys. Sm(Co,Cu) 5, Zr and cell boundary may pin the domain wall, so as to improve the coercivity.