Abstract:Vacuum cold spray is a coating deposition method that is based on the impact and crush of ultrafine ceramic powder particles under room temperature and vacuum condition. Currently, vacuum cold spray has shown good application prospects in the fields of microelectronic devices, metal protection and new energy sources. In this study, LiNi_0.33Co_0.33Mn_0.33O₂ (NMC) coating that is used for the cathode of lithium-ion battery was deposited on alumina substrate by the vacuum cold spray method. The surface and cross-section morphology of the NMC coating were characterized by scanning electron microscopy (SEM). The phase structure of the coating was characterized by X-ray diffraction (XRD). The surface roughness of the coatings was characterized by 3D laser microscope. The effects of deposition conditions such as carrier gas flow rate, spray distance and spray passes on the micro-morphology and particle deposition behavior of the NMC coatings were studied. The results show that particles crush is determined in the vacuum cold spray NMC coatings. The cross-section microstructure of the NMC coatings is dense. The particles deposition behavior is affected by the deposition conditions such as the gas flow rate, spray distance, spray passes. The increase of particle impact speed is increased by the carrier gas flow rate, which results in the increase of the deposition rate of NMC coating. However, excessive gas flow rate leads to particle erosion, which leaves pits on the surface of NMC coatingand results inthe increase of coating roughness. Excessive spray distance results in low impact velocity of NMC particles and inadequate particle fragmentation. The coating is porous at high spray distanceand the structure is similar to agglomerated NMC powder. The coating thickness increases with the increase of spray passes. Under appropriate deposition parameters, the thickness of the coating can be linearly varied by adjusting the spray passes.