Structural and Magnetic Properties of Fe-Co/Al.sub.2O.sub.3 Nanocomposite Powder Produced by Mechanical Alloying

• Published in: Powder metallurgy and metal ceramics 2017-07, Vol.56 (3-4), p.148
• Main Authors: Younes, A, Bacha, N. E, Zergoug, M, Dilmi, N
• Format: Article
• Language: English
• Subjects: Alloys; Magnetic properties; Magnetization; Mechanical properties; Powders (Particulate matter); Specialty metals industry
• ISSN: 1068-1302
• DOI: 10.1007/s11106-017-9881-9

The effect of milling time and addition of elements on the microstructure, magnetic and mechanical properties of the Fe-xCo (x = 0, 5, 10, and 20 wt.%) matrix nanocomposite reinforced with 40 wt.% Al.sub.2O.sub.3 during mechanical alloying is examined. Fe-Al.sub.2O.sub.3 and Fe-Co-Al.sub.2O.sub.3 alloys are milled for 5, 15, 20, and 30 h and 20 h, respectively. The balance between the welding and fracturing and a steady-state situation is found out in the Fe-Co-40 wt.% Al.sub.2O.sub.3 nanocomposite after 20 h, due to the Co introduction into the Fe matrix, but not in the Fe-Al.sub.2O.sub.3 nanocomposite. After 30 h of milling, the average crystallite size was 5 nm in the Fe matrix. The lattice strain increased to ~0.64% in the Fe matrix after [less than or equal to]30 h of milling and in the binary Fe-20 wt.% Co matrix after 20 h of milling; the average crystallite size was 3 nm. The lattice strain increased to ~0.56% for the Fe-20 wt.% Co matrix after [less than or equal to]20 h of milling. The coercive field (H.sub.c) increased from 6.407 to 82.027 Oe, while the saturation magnetization (M.sub.s) decreased from 20.732 to 15.181 emu/g in the Fe matrix during milling. The H.sub.c and M.sub.s are maximum for the binary matrix (20 and 10% Co, respectively).