摘要：

As a new composite spraying technology combining the advantages of laser and cold spray, supersonic laser deposition(SLD) is able to deposit materials which are difficult or impossible to deposit by cold spray technique alone. Ni60 coatings are successfully fabricated on the surface of medium carbon steel by SLD. The deposition efficiency, bonding mechanism, microstructure, composition and micro-hardness are characterized by scanning electron microscope(SEM), energy dispersive spectrometer(EDS), X-ray diffraction(XRD) and microhardness tester, respectively. The results show that the thickness of deposited layer significantly increases with the rising of deposition temperature, the spherical indentation on surface decreases. Compared with Ni60 particles,the Ni60 deposited coating preserves the status of solid-state deposition, and has the same microstructure and phase with powder. The bonding mechanism is mainly mechanical interlocking and metallurgical bonding under laser irradiation. Average micro-hardness of the deposited coating is 867 Hv0.3, which is 8%~10% higher than that of the original powder due to cold hardening.

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