Preparation and Infrared Emissivity of Ni2Cr(BO3)O-2 Coating

Ni2Cr(BO3)O-2 coating, a high infrared emitting coating, was prepared via atmospheric plasma spraying after Ni2Cr(BO3)O-2 powder was prepared by spray granulation and calcining at high temperature. The infrared emissivity of the coating was studied. The surface and section morphology of the coating were observed by SEM and it is found that the coating is closely combined with the matrix. The phase composition of calcined powder was characterized by XRD, mainly containing Ni2Cr(BO3)O-2. According to test result, infrared emissivity of the Ni2Cr(BO3)O-2 coating in the wave band of 0.76-2.5 mu m is 0.896 while that in the wave band of 2.5-14 mu m is 0.925, which indicates that the coating possesses excellent infrared emission performance. Lattice distortion, asymmetry and electron transfer transition in the Ni2Cr(BO3)O-2 structure cell are the main reasons for high infrared emissivity. Ni2Cr(BO3)O-2 coating can withstand thermal shock circles of 37 times from 900 degrees C to 20 degrees C of water. The coating has high practical application value due to its high infrared emissivity, good thermal shock resistance and thermal stability.