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A NiFeBSiNb amorphous/nanocrystalline composite coating was prepared through flame thermal spraying, where a gas atomized alloy powder substituted an amorphous powder. The microstructure and thermal behavior of the laboratory-produced powders and the produced as-sprayed coating were characterized. The results demonstrated that the powder, which was spherical or ellipsoidal, was mainly consisted of the Nb₂Ni₂₁B₆ and (Ni,Fe)₂₃B₆ crystalline phases, whereas the as-sprayed coating was consisted of a glassy structure and certain nanocrystalline phases. It was observed through calculations that the Rc (critical cooling rate) of the powder and the as-sprayed coating for the amorphous phases formations were 6.01×10₅ K/s and 4.56×10₃ K/s, respectively. A probable explanation for the amorphous structure, as it occurred in the as-sprayed coating, was rapid quenching from the melt at the cooling rates which exceeded the critical cooling rate Rc. The prepared coating of these as-sprayed amorphous coatings displayed the properties of a 0.17 low friction coefficient and excellent wear resistance.