Thermal spraying is an important supporting technology in the field of remanufacturing engineering. The preparation of Fe-based amorphous coatings by thermal spraying has received extensive attention in the engineering field due to its excellent performance and high cost-performance. The dense Fe-based amorphous nanocrystalline coatings were prepared on Q235 steel substrate by HVOF spraying in this paper. Using High Entropy Experimental Design analysis method to design experimental parameters and establish BP neural network model, the influence rule of coal oil quantity, oxygen quantity, powder feeding rate and spraying distance effect on the porosity, hardness, bonding strength and deposition efficiency of the coating. The microstructure of the powder and coating were characterized by scanning electron microscope, metallographic microscope and transmission electron microscope. In addition, energy spectrum analyzer, X-ray diffraction, synchronous thermal analyzer and other methods were used to observe and analyze the phase constitution and amorphous content of the powder and the prepared coating. This study determined the optimum spraying parameters after verifying the simulation results and improved the performance of the coating. The microscopic process of pore formation during spraying, the relationship between the formation principle of amorphous nanocrystalline and the coating performance were discussed as well. The results showed that many factors influenced each other on the coating performance, theoretically the optimal spray parameters of coating were kerosene 23L/H, oxygen 51 L/H, powder feeding rate 72 g/min, and spraying distance 280mm. The thickness of the prepared iron-based amorphous coating was about 280 μm, the porosity was about 1.3%, the binding strength was about 84MPa, and the hardness was about 1110 HV0.3. The amorphousness degree of the coating was about 75%, and the nanocrystalline size was 3-5nm.
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