Influence of vacuum annealing temperature on damping performance of NiCrAlY composite coatings

NiCrAlY coating was prepared by arc ion plating and annealed in vacuum, which improved the bonding strength between the coating and the substrate and improved the damping performance of the alloy. The microscopic morphology, elemental composition and physical phase of the NiCrAlY coatings were analyzed at different vacuum annealing temperatures, and the relationship between the damping properties of the coatings and the applied load and ambient temperature was investigated. After annealing at 650 degrees C and 750 degrees C, cracks, pores and cluster structures were generated on the surface of the coatings, and a transition layer of hard compounds was newly generated at the interface. At annealing temperatures above 850 degree celsius, the coating precipitated irregular barshaped structures of gamma'- Ni3Al. All these phenomena are favorable for the improvement of the damping performance of the coating. According to the change rule of the damping performance of the composite structure coating and the uncoated substrate, the best annealing temperature is 650 degrees C similar to 850 degrees C. The applicable working temperature and strain range of the composite structure coating are summarized. It can be concluded that NiCrAlY coating is a potential vibration damping coating, and vacuum annealing can enhance the damping performance of NiCrAlY composite structure coating.