In situ fabrication of iron-nickel/alumina nanocomposite powders

FeNi intermetallics, so called Permalloy, are attractive because of their excellent physical properties such as high melting point, good thermal expansion coefficient, high permeability, superior oxidation and corrosion resistance at elevated temperature and excellent magnetic performance. Moreover it was shown that the mechanical properties of this material can be improved by dispersion of hard secondary phase such as Al2O3 within the FeNi matrix and decreasing the grain size of the matrix and reinforcement particles size to the nano scales. FeNi- Al2O3 nanocomposites are specific choice as the advanced materials in automoile and electronic industries. In the present study, FeNi– Al2O3 nanocomposite were in situ synthesized by mechanical alloying of Fe2O3, Al and Ni powder mixture. The effects of various parameters such as chemical composition of starting materials, milling time and annealing on the phase evolution, morphology and microhardness of samples were investigated. The results indicated that FeNi matrix nanocomposites reinforced with 10, 15 and 30Wt% of Al2O3 were fabricated in 300, 240 and 180 min of milling respectively. The crystallite size of the intermetallic FeNi phase and particle size of Al2O3 in the 720 min milled FeNi-30Wt% Al2O3 nanocomposite sample was calculated 28nm and 5.15 µm respectively. This sample also has the maximum hardness value of 790 HV.

کلیدواژه ها:

Powder metallurgy ، Warm compaction ، Sintering ، Mechanical properties