Heat transfer studies of surface synthesized by chemical vapor deposition
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ORIGINAL
Heat transfer studies of surface synthesized by chemical vapor deposition Vamsi Krishna Bhasuru 1 & Shivasheesh Varshney 1 & Yashasvi Agarwal 1 & P. Kalaichelvi 1 Received: 30 March 2020 / Accepted: 24 July 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract In this paper, heat transfer characteristics of nickel coating over aluminium and mild steel are examined using jet impingement cooling. A rectangular sheet of dimension 10 cm × 3.5 cm × 0.1 cm taken as the test piece is coated with 4 g nickel acetate tetrahydrate precursor in the chemical vapor deposition (CVD) process for 85 mins. Heat transfer characteristics are studied on three layers of nickel coating (no coating, first coating, and second coating) with an impinging air-jet velocity of 3.5 ms−1 and 6 ms−1. The effect of Reynolds number, the thickness of the coating, jet velocity, distance from the stagnation point, and nozzle diameter on the heat transfer coefficient are investigated. The results show an increase in convective heat transfer characteristics with the Reynolds number, the thickness of the coating, and the nozzle diameter and a substantial decrease with deviation from the stagnation point. Keywords Chemical vapor deposition . Jet impingement . Heat transfer characteristics . Nickel acetate Tetrahydrate . Nickel coating . Mild steel . Aluminium
Nomenclature DH Hydraulic diameter [m]. v Velocity [ms−1]. T Temperature [K]. h Convective heat transfer coefficient [Wm−2 K−1]. D Characteristic length of the body [m]. k Thermal conductivity [Wm−1 K−1]. Q Heat transfer rate [W]. V Voltage [Volts]. I Current [Ampere]. Dp Particle size [nm]. d Nozzle diameter [mm]. x Distance from the point of impingement [cm]. K Constant related to crystal shape. Abbreviations CVD Ni(hfa)2 Ni(CO)4 Ni[(acac)2en]
Chemical vapor deposition Ni(hexafluoroacetylacetonate)2 Nickel Tetracarbonyl Nickel bis(acetylacetone) ethylenediamine
* P. Kalaichelvi [email protected] 1
Department of Chemical Engineering, National Institute of Technology, Tiruchirappalli, Tamil Nadu, India
Chromium (III) acetylacetonate Cr(acac)3 XRD X-Ray diffraction Dimensionless Nu Nusselt number. Re Reynolds Number. Greek letters μ Dynamic Viscosity [kgm−1 s−1]. ρ Fluid density [kgm−3]. λ Wavelength of x-ray [Å]. β Half peak width of the diffraction peak [radians]. θ Angle between diffracted wave and the lattice plane [degrees]. Subscripts a Air. w Wall. x Distance from the wall. l Local. s Stagnation.
1 Introduction Functional coatings on the surface of a material can significantly improve its chemical, mechanical, thermal, and electrical properties [1, 2]. In the CVD process, thin-film coatings
Heat Mass Transfer Fig. 1 Technical schematic of CVD reactor
are deposited on the surface of the substrate by chemical reaction of the precursor(s) with the surface material inside the reactor [3–5]. It is a rapidly developing technique as the coating produced is highly pure and uniform, with a good growth rate and reproducibility to reach all corners of the substrate [6,
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