Microstructure and Properties of Laser Cladding Stellite 12/TiC/CaF2 Composite Coating on Copper Substrate
Stellite 12/TiC/CaF2 composite coating has been successfully fabricated on copper substrate by a pulsed Nd:YAG laser system with preplacment powder bed to improve the absorbance of copper substrate to laser energy. Microstructures, phases and wear properties were studied by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), dry sliding wear tester. The results showed that the existence phases of Co-based solid solution, Cr4Ni15W, TiC, Cr23C6, CaF2 and Ti8C5. The morphology of titanium carbide is mainly spherical and exists in two forms, one is TiC and the other is Ti8C5. The microhardness of the layers reveals a gradient variation along the cross section of the LSA layers. The friction coefficient of the coating is oscillating around approximately 0.17 because CaF2 is a solid lubricant because of the lamellar structure and softness and Titanium carbide is hard. The dry sliding wear testing shows the wear resistance of as-receive copper is significantly improved by laser cladding Stellite 12/TiC/CaF2 composite coating.
Liangchi Zhang, Chunliang Zhang and Tielin Shi
W. Y. Wang et al., "Microstructure and Properties of Laser Cladding Stellite 12/TiC/CaF2 Composite Coating on Copper Substrate", Advanced Materials Research, Vols. 139-141, pp. 422-425, 2010