Conductive Heat Transfer Behaviour of Electro-deposited Nickel-Tungsten Alloy Coating

Abstract

777-780Thermal barrier coatings are normally employed over the base metals subjected to elevated temperatures to protect the base materials from the severe operating thermo cyclic load conditions<span style="mso-bidi-font-style: italic"> and to improve their performance. This paper deals with the conductive heat transfer behaviour of nano-crystalline nickel- tungsten electro-deposit over the mild steel substrate by choosing optimum parameters for the electro-deposition technique. The high quality deposit was prepared with 10 µm and 50 µm thickness, and the conductive heat transfer performance of the coatings was studied by a specially designed and fabricated experimental setup. The characterizations of the coated surfaces were carried out by various surface topography methodologies (XRD, EDAX and SEM). The heat transfer studies on the nano-sized nickel-tungsten alloy coatings reveal that the nano-coatings with a particle size of around 92 nm, exhibits nearly 9 – 18 % of temperature reduction in the 50µm thickness coating, whereas an observation of 9 - 13 % of temperature reduction was notified in the 10µm<b style="mso-bidi-font-weight: normal"> thickness deposit. </span