Abstract: Plasma cladding technology was used for in-situ synthesis of TiC/Ni composite coating. The microstructure and properties of the coating were investigated by optical microscope, scanning electron microscope, X-Ray diffractometer, transmission electron microscope and microhardness tester. The results show that excellent bonding between the coating and the carbon steel substrate is ensured by the strong metallurgical interface, and the coating is uniform, continuous and almost defect-free when [Ti+C] is varied from 10% to 20% after ball milling. The microstructure of the plasma-cladded coating is mainly composed of γ-Ni dendrite, M23C6 , CrB and TiC ceramic particle which is synthesized in-situ. Most of TiC particles are spherical and a small fraction are blocky. TiC particle size is 1-2μm. The particles at the bottom are smaller than those near the top of the coating, and dispersivly distributed in the cladded coating. The maximum hardness of the coating is HV0.1 1000, and 4 times of the microhardness of the steel substrate
Microstructure and properties of in-situ synthesis of TiC particle reinforced composite coating by plasma cladding
Abstract:
Plasma cladding technology was used for in-situ synthesis of TiC/Ni composite coating. The microstructure and properties of the coating were investigated by optical microscope, scanning electron microscope, X-Ray diffractometer, transmission electron microscope and microhardness tester. The results show that excellent bonding between the coating and the carbon steel substrate is ensured by the strong metallurgical interface, and the coating is uniform, continuous and almost defect-free when [Ti+C] is varied from 10% to 20% after ball milling. The microstructure of the plasma-cladded coating is mainly composed of γ -Ni dendrite, M23C6 , CrB and TiC ceramic particle which is synthesized in-situ. Most of TiC particles are spherical and a small fraction are blocky. TiC particle size is 12 μm. The particles at the bottom are smaller than those near the top of the coating, and dispersivly distributed in the cladded coating. The maximum hardness of the coating is HV0.1 1000, and 4 times of the microhardness of the steel substrate.
图3 [Ti+C] 为25%时的熔覆层组织 Fig.3 Microstructures of plasma cladded coating([Ti+C]=25%) (a)—Whole cladding coating; (b)—Interface at coating and substrate; (c)—Near bottom of coating; (d)—Near top of coating