Optimization of cobalt content in FeCo alloys for enhancements ofsaturation magnetization

Alloys based on the near-equiatomic FeCo offer exceptional magnetic properties. The equiatomic alloy was ‘invented’ in 1929, it offers a saturation hardly lower than that of the maximum obtained for Fe-0.35Co, with higher permeability and a lower coercivity than the latter. However, this alloy remained without industrial application, mainly because of its extreme brittleness. FeCo alloys as soft magnetic materials are known to exhibit very high magnetic moments.FeCo intermetallic alloys are well known to possess a unique combination of high saturation magnetisation, high Curie temperature, low magnetocrystalline anisotropy and good strength. They are ideally suited for applications requiring high flux densities. Intense research and development efforts over the years resulted in significant improvements in mechanical properties and better understanding of phase transformations in FeCo alloys. However, the high cost of the alloys has prevented their widespread applications. Emergingneeds for soft magnetic materials to operate at high temperatures have caused renewed interest in FeCo alloys.In this research, mechanical alloying Fe-Co compounds is taken. Alloying operations for the duration of 15, 20, 25 and 30 hours. Mechanical alloying compounds of Fe and Co was performed under argon atmosphere. (X = 0.2, 0.25, 0.3, 0.35, 0.4 ,0.45 and 0.5) powders were prepared bymechanical alloying after 15,20,25 and 30 hours. magnetic properties were investigated based on microstructure. The saturation magnetization of the mixtures of Fe and Co increases with milling time, indicating an increasing homogeneity in composition and the phase formation. To studythe phase consisting of X-ray diffraction was used. Scanning electron microscopic analysis to determine the morphology of the particles wasused. SEM magnification of 100x, 1000x, 2000x and 10000x was taken. EDS analysis to determine the composition of the sample imaging was used at certain points. Magnetic properties were evaluated using a vibrating sample magnetometer. X-ray diffraction analysis results for each combinations represents, the length of alloying with cobalt percentage is increasing. Generally, the composition contains the least amount of cobalt, Solid solution alloying process time to completion is 30 hours. The composition contains 50 wt% cobalt optimal milling time, 20 hours. According to evaluate the magnetic properties of synthesized samples, combined -40% by weight of iron cobalt the highest saturation magnetization of 266 (emu / g) for 15 hours milling that it has reached the saturation magnetization.The optimal time for other compounds such as iron, cobalt -20% by weight and the saturation magnetization of 30 hours and 248/5(Oe) and coercivity 10/5 (Oe) is obtained. The combination of Fe-25 wt% cobalt, and the optimal time of 25 hours and the saturation magnetization is 260(emu/g). The combination of Fe-30 wt% cobalt, and the optimal time of 20 hours and the saturation magnetization Psmandza, 208 and 9. The combination of Fe-35 wt% cobalt, and the optimal time of 10 hours and the saturation magnetization and coercivity, is 245(emu/g) and 8/2(Oe). The combination of Fe-50 wt% cobalt, and the optimal time of 20 hours and the saturation magnetization and coercivity, is 241/5(emu/g) and 11/4(Oe). The most optimal chemical composition, composition of Fe-40 wt% cobalt alloy is obtained within 15 hour

کلیدواژه ها:

mechanical alloying ، FeCo ، magnetic properties