Production and Determination of the Magnetic Properties of the Fe-36Ni Nanopowder via Electrical Explosion of Wire in Water and Compacted Alloy

摘要

Fe-36Ni alloy nanopowder was prepared via electrical explosion of wire in DI water. The nanopowder was reduced in hydrogen at 500℃ for 30 min. Spark plasma sintering at 800 and 1000℃ for 10 min was used to obtain bulk samples from the hydrogen-reduced nanopowder. The sintered samples were annealed at 500℃ for 2 h. X-ray diffraction was used to analyze the phases of the nanopowder and sintered samples. The results showed that the sintered samples were formed in γ-(Fe-Ni) solid solution. The particles sizes and morphologies of the as-synthesized and hydrogen-reduced nanoparticles were observed via transmission electron microscopy. The morphologies of the assynthesized nanoparticles had spherical core-shell structures. Core was γ-(Fe-Ni) and the shell was FeO. The nanoparticles of the as-synthesized and hydrogen reduced samples were found to be nearly spherical in shape, with average diameters of 32 and 70 nm, respectively. The hysteresis loops of the as-synthesized nanopowder, hydrogen reduced nanopowder, and sintered samples revealed ferromagnetic characteristics.