The improved thermal radiation property of SiC doped microarc oxidation ceramic coating formed on niobium metal for metal thermal protective system

The thermal radiative property of microarc oxidation (MAO) coated and uncoated niobium metal is not available in the elevated temperature, while it is a key requirement for dissipating heat evaluation for metal thermal protective system (MTPS) applications. In this paper, the effects of MAO coatings with and without SiC doping on infrared emissivity property at elevated temperature were studied. The phase, chemical composition, surface and cross-sectional morphologies were characterized by XRD, EDS, XPS and SEM techniques. The undoped coating mainly consists of Nb2O5 phase. A small amount of micro sized SiC was incorporated into the coating during microarc discharging process with the addition of SiC particles in the electrolyte. The SiC doped MAO coating promotes spectral emissivity of low wave brand (3-10 mu m), which is almost 0.1 higher for coating with SiC 12 g L-1 doping than undoped coating. While, the high emissivity in 8 <lambda<20 pm is attributed to the higher relative FTIR absorption of H-Nb2O5 caused by the lattice aberrance and low structural symmetric. (C) 2016 Elsevier B.V. All rights reserved.