Ni-14&nbsp;at.% W/SiC nanocomposite coatings containing 0-6&nbsp;vol.% of submicron size (0.35&nbsp;μm) SiC particles were obtained using pulsed electrodeposition technique on mild steel substrate. The coatings were subsequently characterized for uniformity of SiC distribution, grain size and mechanical properties (hardness and elastic modulus) using SEM, XRD and nanoindentation techniques, respectively. It was observed that the SiC particulates were uniformly distributed within the coating. The coating matrix (Ni-W) also exhibited nanograin size. Tribological behavior of&nbsp;Ni-14&nbsp;W/SiC nanocomposite was analyzed under dry sliding wear test conditions using pin on disk method. The interrelationship between SiC content, interparticle spacing, mechanical properties and wear behavior was analyzed. The results suggest that whereas hardness and modulus of nanocomposite coatings varied with SiC content as per Rule of Mixtures, wear mechanism can be best explained on the basis of Inverse Rule of Mixtures. © 2018, ASM International.

Sundararajan G

Department of Metallurgical and Materials Engineering

Binary alloys

Coatings

Electrodeposition

Electrodes

Hardness

Inverse problems

Matrix algebra

Mechanical properties

Mixtures

Nanocomposites

Silicon carbide

tribology

Tungsten alloys

Wear of materials

HARDNESS AND ELASTIC MODULUS

INTER-PARTICLE SPACING

MILD STEEL SUBSTRATES

Nano-composite coating

Nanoindentation techniques

NICKEL-TUNGSTEN

PULSED ELECTRODEPOSITION TECHNIQUES

TRIBOLOGICAL BEHAVIORS

Metallic matrix composites

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Journal of Materials Engineering and Performance

The present study deals with the electrodeposition and structural characterization of as-deposited and heat treated nickel-tungsten (Ni-W) alloy coatings. The coatings were deposited using pulse reverse electrodeposition (PRED) and pulse electrodeposition (PED) from a Ni-W plating bath. Wide range of alloy compositions have been obtained with tungsten (W) percentage in the alloy ranging from 0% to 25&nbsp;at% by altering pulse parameters. The coatings were subsequently heat treated at a temperature of 700&nbsp;°C for 1&nbsp;h and were characterized in terms of phases present, grain size, hardness and elastic modulus. It was observed that the coatings were crystalline up to 12&nbsp;at% W and beyond which the coatings were found to be a mixture of amorphous and crystalline phases. Heat treatment resulted in crystallization of amorphous phase and precipitation of secondary phases. Substantial grain growth had occurred after heat treatment and as a result, the hardness of heat treated coatings was found to be less than that of their as-deposited counterparts up to 17&nbsp;at% W. Beyond 17&nbsp;at% W hardness of heat treated Ni-W was found to be higher due to dispersion hardening. © 2017 Elsevier B.V.

Surface and Coatings Technology

Influence of heat treatment on microstructure and mechanical properties of pulse electrodeposited Ni-W alloy coatings

Silicon carbide (SiC) was reinforced in the pulse electrodeposited nickel-tungsten (Ni-W) coatings deposited on the steel substrate, and isothermal oxidation test was performed at 1273&nbsp;K (1000&nbsp;°C) for 24 hours. Addition of just 2&nbsp;vol&nbsp;pct of SiC showed 26&nbsp;pct increase in the relative oxidation resistance of Ni-W coating. The increased oxidation resistance was attributed to the phase evolution (SiO2, Cr2O3, CrSi2, Ni2SiO4, Cr7C3, Cr3C2, and Cr3Si), which suppressed the spallation of the oxide scale in Ni-W-2&nbsp;vol&nbsp;pct SiC. The presence of Fe2O3 phase in the oxidized Ni-W coating was mainly responsible for the major multiple spallations at the interface and in the bulk, which resulted in the degradation of oxidation resistance. © 2016, The Minerals, Metals &amp; Materials Society and ASM International.

Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science

Role of Silicon Carbide in Phase-Evolution and Oxidation Behaviors of Pulse Electrodeposited Nickel-Tungsten Coating

Ni-W/SiC nanocomposite coatings were systematically deposited at varying pulse parameters and subsequently characterized using SEM, XRD, TEM for surface morphology, composition and SiC particle/Ni-W matrix interface phase boundary. In addition, mechanical properties of nanocomposite were also evaluated using nanoindentation. Uniform distribution of submicron SiC particles in nanocrystalline Ni-W alloy coatings was obtained using pulsed electrodeposition. The results indicated increase in SiC content of nanocrystalline Ni-W matrix with increase in pulse frequency and decrease in duty cycle. The incorporation of SiC was attributed to pulse current effect at cathode-solution interface leading to changes in pulsating diffusion layer thickness. A simplified mechanism of composite electrodeposition is proposed. The hardness and modulus of nanocomposite varied with SiC content. The variation in mechanical properties was rationalized based on rule of mixture and inverse Hall-Petch effect. © 2016 Elsevier Ltd

Materials and Design

Pulsed electrodeposition and mechanical properties of Ni-W/SiC nano-composite coatings

The main purpose of the present work is to study the influence of current density, deposition mode and the presence of saccharin as an additive on the microstructure, sulfur content, grain size and microhardness of nanocrystalline Ni coatings. Towards this purpose, nanocrystalline nickel (Ni) coatings were deposited at various current densities in Watt's bath using direct, pulse and pulse reverse current (PRC) electrodeposition and subsequently characterized for sulfur content, grain size and hardness. It was observed that, the current density has no influence on the grain size/hardness of nanocrystalline Ni coatings in direct and pulsed current electrodeposition mode. However, the grain size increased from ~ 20 to ~ 200 nm with decrease in current density in PRC mode of deposition. In addition a substantial change in microstructure and texture of PRC Ni coatings was also evident. The experimental results have been rationalized based on the adsorption-desorption type of mechanism during electrodeposition. © 2016 Elsevier B.V..

Influence of mode of electrodeposition, current density and saccharin on the microstructure and hardness of electrodeposited nanocrystalline nickel coatings

Journal of Alloys and Compounds

Mechanical and tribological properties of Ni-W-TiB2 composite coatings

Tribological Behavior of Pulsed Electrodeposited Ni-W/SiC Nanocomposites

Journal	Data powered by TypesetJournal of Materials Engineering and Performance
Publisher	Data powered by TypesetSpringer New York LLC
ISSN	10599495
Open Access	No