Optical thermostability and weatherability of TiN/TiC-Ni/Mo cermet-based spectral selective absorbing coating by laser cladding

Abstract

In the present work, a monolayer of micro-nano scale TiN/TiC-Ni/Mo ceramic solar spectral selective coating was deposited on the stainless steel substrate by laser cladding. The absorptance (α) and emittance ( ε ) of the coating prepared at the mixed scale of TiN/TiC-Ni/Mo were 80.1% and 2.24%, respectively. After annealing at 600 °C for 24 h, the absorptance increased to 80.8% and the emittance was 1.9%. The ratio of absorptance to emittance is α/ԑ = 42.52. This study showed that the thermal stability and optical properties of the ceramic coating was excellent under high temperature. It also provides a new idea for the preparation of solar absorbing coatings in the future. • A laser cladding method was proposed to prepare the solar energy selective absorption coating which is a promising preparation technology. • The multi-scale particles enhances the absorption performance of the coating and significantly reduces the emittance of the coating. • The single-layer cermets coating has excellent optical properties and the long-term thermal stability. • The dilution rate was researched by theoretical simulation and experiment, which directly influences the weather resistance of the coatings.