Microstructure, mechanical performance, thermal stability, and oxidation resistance of AlCrN/AlCrBN nano-multilayer coating

This study synthesized three different coatings using multi-arc ion coating technology: AlCrN, AlCrBN monolayer, and AlCrN/AlCrBN nano-multilayer coatings. A comparative investigation was conducted on the microstructure, mechanical performance, thermal stability, and oxidation properties of coatings. The results indicate the AlCrN, AlCrBN, and AlCrN/AlCrBN nano-multilayer coatings consist of face-centered cubic solid solution fcc-(Cr, Al)N phase. AlCrN/AlCrBN nano-multilayer coatings also exhibit better thermal stability and oxidation resistance than AlCrN and AlCrBN monolayer coatings. The AlCrN/AlCrBN nano-multilayer coatings have a dense, protective, Al2O3 layer formed during high-temperature oxidation. During high-temperature oxidation, the AM (amplitude modulation) decomposition of the AlCrN and AlCrBN monolayers in the AlCrN/AlCrBN nanolayers is inhibited by the structure of the multilayer coatings. The formation of dense oxides on the surface prevents the diffusion of Al and Cr atoms to the outside and prevents the diffusion of oxygen from the outside to the inside of the AlCrN/AlCrBN nanolayers.