Thermal behavior and structure of Fe84Nb7B9 nanocrystalline powders
(1.School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Zhuzhou Cemented Carbide Group Co Ltd, Zhuzhou 412000, China;
3.Department of Science and Technology of Anhui Province, Hefei 230001, China)
2. Zhuzhou Cemented Carbide Group Co Ltd, Zhuzhou 412000, China;
3.Department of Science and Technology of Anhui Province, Hefei 230001, China)
Abstract: The thermal behavior of Fe84Nb7B9 nanocrystalline powders were analyzed by DTA, XRD and TEM measurements. The results show that nanocrystalline powders with grain size of less than 10 nm can be prepared by mechanical alloying. After annealed below 770 ℃, the obtained powders remain in the scale of nanometer without new phases formed, exhibiting good thermal stability. On its DTA curve, a wide temperature interval of 450 ℃ between its two exothermic peaks can be observed. The powders in as-milled state has bcc structure of supersaturated solid solution type, and nanocrystalline together with amorphous phases can be observed in the powder annealed at 350 ℃, which is beneficial for the good soft magnetic properties.
Key words: Fe84Nb7B9; nanocrystalline; amorphous phases; thermal behavior; magnetic properties