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A mixture of NiCrSiB alloy powder and tantalum (Ta) powder was used as laser clad material to improve abrasive wear resistance of the Ni-based coating. The microstructure and wear resistance of the coating were investigated. Addition of Ta element works to suppress the growth of coarse M7C3 carbide in the coating, resulting in a decrease in aspect ratio of coarse carbide. In the abrasive wear test, in situ synthesized TaC particles well bond with Ni-based matrix, and are hardly pull out from wear surface. Grooves on the worn surface of NiCrSiB coating are much deeper and sharper than those in the NiCrSiB+Ta composite coating. Also, a weight loss of the composite coating is much lower than that of the NiCrSiB coating. The wear resistance of the laser clad Ni-based coating is enhanced to a much greater extent through the addition of Ta. This is attributed to the in situ synthesized hard TaC particles of nearly equiaxed shape, the Ni-based matrix strengthened by Ta and the decrease in aspect ratio of the coarse brittle carbides.
A mixture of NiCrSiB alloy powder and tantalum (Ta) powder was used as laser clad material to improve abrasive wear resistance of the Ni-based coating. The microstructure and wear resistance of the coating were investigated. Addition of Ta element works to suppress the growth of the coarse M7C3 carbide in the coating, resulting in a decrease in aspect ratio of coarse carbide. In the abrasive wear test, in situ synthesized TaC particles well bond with Ni-based matrix, and are hardly pull out from wear surface. Grooves on the worn surface of NiCrSiB coating are much deeper and sharper than those in the NiCrSiB + Ta composite coating. Also, a weight loss of the composite coating is much lower than that of the NiCrSiB coating. The wear resistance of the laser clad Ni-based coating is is enhanced to a much greater extent than the addition of Ta. This is attributed to the in situ synthesized hard TaC particles of nearly equiaxed shape, the Ni-based matrix strengthened by Ta and the decrease in asp ect ratio of the coarse brittle carbides.