Studies on Electrodeposition, Microstructure and Physical Properties of Ni-Fe/In₂O₃Nanocomposite

Abstract

In 2 O 3 nanoparticles (<100 nm) up to 5 wt% are incorporated into Ni-Fe alloy matrix by electrodeposition which enhance both corrosion resistance and hardness. Plating parameters like current density, concentration of metal ions and In 2 O 3 particles, agitation and the temperature of the bath were optimized to achieve acceptable quality of the coatings. Effect of current density on the development of Ni-Fe/In 2 O 3 nanocomposites and their physical properties was mainly studied. Coatings thus obtained were characterized by SEM-EDAX, XRD, TEM and AFM and surface morphology, crystal structure, microhardness, corrosion resistance, magnetic behavior and electrical resistivity of the nanocomposites were studied. The incorporation of conducting In 2 O 3 particles in a alloy matrix resulted in a higher electrical conductivity than the matrix. X-ray diffraction results showed that the incorporation of In 2 O 3 particles does not affect the Ni-Fe alloy fcc structure but alters the texture of the deposits favoring (111) crystallographic orientation and is independent of the applied current density for deposition. The crystallite size of the nanocomposites is found in the range of 5-13 nm with almost negligible strain.Metal matrix nanocomposite films have drawn great interest due to their unique properties e.g. mechanical, electrical, magnetic and corrosion resistant properties compared with those of conventional materials. 1-4 Out of several techniques for fabrication of alloys and composites, electrodeposition method has been widely used during the past several decades due to its more technologically feasible and economically superior nature and it is emerging as method of choice for the deposition of nanocomposite films in past few years. 2,3,5,6 The electrodeposition of metals is greener route of thin film growing and may also be of interest for fundamental studies of their nanometric nature. The reinforced particles can significantly improve the properties of the coatings depending on the nature, size, concentration and distribution of particles. 5,7 Electroplating parameters like current density, concentration of electrolyte and ceramic particle, temperature, stirring rate and duration of electrolysis also influence the properties of nanocomposites. 8,9 Superior mechanical properties of nickel-iron alloy have been reported by many investigators 10,11 which are strongly dependent on the iron content of the deposits. Permalloy (80 wt% Ni, 20 wt% Fe) has promising properties for practical applications e.g. their interesting magnetic and mechanical properties. Nanocrystalline Ni-Fe magnetic thin films gradually replaced the traditional micro-crystalline magnetic material due to their significant soft magnetic properties. In the past 4,5,12,13 some effort has been made to study the nanocrystalline nickel-iron alloy matrix composites with various type of ceramic particles owing to their excellent physical properties, however corrosion behavior, magnetic and electrical properties of such coatings have not been studied in d...

Microstructure and Properties of Electrodeposited nc-TiO2/Ni–Fe and Ni–Fe Coatings

“…However, our measurements are the opposite to the observations related to H c and point to a small decrease in coercivity with the addition of nc-TiO 2 . In turn, our results are consistent with those obtained by Chaudhari et al [28] who noticed a significant effect of In 2 O 3 nanoparticles on the decrease of coercivity in In 2 O 3 / Ni-Fe composites. It is known that M s in Ni-Fe binary systems decreases with the Ni concentration [39], which is related to the value of saturation magnetization of Ni and Fe equal to 55 emu/g and 217 emu/g, respectively [40].…”

“…In electrodeposited composites, nc-TiO 2 could act as the blocker of plastic deformation, grain boundary sliding or dislocation movements in composites. A similar effect of hardness improvement was obtained for another metal oxides such as ZrO 2 [11], In 2 O 3 [28], WO 3 [43], as well as micron-sized Si and nano-sized TiO 2 particles [44]. The results of hardness measurements of electrodeposited Ni-Fe alloys reported by [11,43] were in the range 410-660 HV and these values are consistent with our findings.…”

“…Danilov et al, in electrodeposited nc-TiO 2 /Fe composites, obtained concentrations of nc-TiO 2 in the range 2.0-6.0 wt%, depending on the concentration of nanoparticles in the bath and current density [26]. Mohajeri et al [27], using PC conditions, incorporated more than 11 wt% of sol-gel synthesized TiO 2 particles in the Ni matrix. was reported that also incorporation of ZrO 2 nanoparticles into the Ni-Fe matrix provides to obtain granular surface morphology [11].…”

“…There are several concepts explaining the influence of oxide and/or nitride particles on the surface morphology of Ni-Fe-based composites. Chaudhari and Singh [28] showed that the incorporation of In 2 O 3 nanoparticles during the electrodeposition of Ni-Fe leads to a decrease in the surface roughness due to the reduction in grain size. On the contrary, other studies indicated that Al 2 O 3 [29] or Si 3 N 4 [30] particles influence the increased roughness of the electrodeposited Ni-Fe composites.…”

“…In ZrO 2 / Ni-Fe composites deposited in DC conditions, the ECD of grains determined using TEM images was in the range of 50-60 nm, but the XRD method revealed a smaller value of about 11 nm [11]. In addition, the reinforcement of Ni-Fe by In 2 O 3 particles, measured by XRD, reduced the size of crystallites even from 16 nm to 5 nm [28]. In light of the above, the results of our experiments are consistent with the findings of other researchers.…”