Structural Features and Functional Properties of Y2O3 Reinforced Nickel Matrix Nanocomposites

Metal matrix composites with yttria as reinforcement are mostly produced because of it's improved mechanical properties while thermal stability, electrochemical and magnetic properties of the yttria based composites are rarely considered. In the present study, the feasibility of incorporating yttria nanoparticles into nickel matrix from ethylene glycol bath by electro-codeposition method is demonstrated. The particle content of the coatings was strongly influenced by current density i. e. the rate of metal deposition. Particle content, surface morphology and microstructural changes of the deposits were investigated by scanning electron microscope (SEM) equipped with energy dispersed X-ray analyzer (EDAX). A dense, compact and smoother composite surface with lower particle content was obtained at higher current densities. Crystallographic structure, texture and lattice strain have been evaluated using X-ray diffraction (XRD). Incorporation of yttria particles inhibits the grain growth and causes grain refinement of the nickel matrix. Annealed nanocomposite deposits revealed thermal stability up to 700 degrees C. The comparative electrochemical corrosion behavior of the electrodeposited coatings in 3.5 % NaCl solution and their deposition potential were evaluated. Magnetic studies showed nearly complete absence of hysteresis i. e. soft magnetic nature of the coatings.