Microstructure and Properties of Electrochemically Deposited Ni-Fe/Si₃N₄Nanocomposites from a DMF Bath

Abstract

This paper deals with successful co-deposition of Ni-Fe/Si3N4 nanocomposites applying various current densities (0.5–3.0 A dm−2) from a sulfamate–DMF (N,N-dimethylformamide) bath containing different concentration of Si3N4 nanoparticles. The nanocomposits have been characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, atomic force microscopy and Energy Dispersive X-ray Analysis. The microhardness, magnetic and electrical properties along with thermal stability has been evaluated. A maximum of 13.6 wt% Si3N4 particles is incorporated in the metallic matrix from 10 g/L bath load of the ceramic particles. The matrix has face-centred-cubic structure. The crystallite size of the nanocomposites is found in the range of 8–13 nm while the strain values ranged between 0.0081 and 0.01. The magnetic measurement reveals superparamagnetic character of the coatings. Occlusion of nano-Si3N4 renders superior hardness to the matrix metal. The hydrogen content in the coatings is minimal, i.e. nearly 6 ppm, which does not cause any adverse effect on the micro- and crystallographic structure of the composites.