Laser And Thermal Spray Surface Modification Coating

The surface coating can improve the metal materials' hardness and wear resistance. In the field of coating technologies, TIN coatings are often used to increase both the wear resistance and the corrosion resistance of a material. Several surface engineering techniques can be used to produce a TiN coating. High hardness and high wear resistance can be made for TiN coating on pure Ti by laser nitriding. This paper used laser nitrided coatings, plasma sprayed ceramic coatings for improving the metals material's hardness and friction resistance so that the metal materials' uses can be extanded.Studies of formation of titanium nitride layer with laser nitriding in a pure Ti in nitrogen atmosphere are described. OM, SEM, TEM, XRD, a hardness taster and friction taster were used to understand the microstructure and to characterize the phases. The distributions of N, Ti in nitrided layer were discussed. The results show that the hardness in the melt zone changed from 500Hv to 900Hv. The coefficient for coating is 0.13.Ceramic coatings Al2O3-45%TiO2 on 45 steel substrate were fabricated with plasma spraying. Bottom coatings NiCrAl was between the substrate and ceramic coatings. SEM, XRD, EPMA, EDAX, a hardness taster and friction taster were used to understand the microstructure, to characterize the phases and to discuss the distribution of Al2O3, TiO2. The results show that the coatings take lamellar structure morphology, and the Al2O3+TiO2 ceramic coating consists of y -Al2O3, TiO2 and a small a mount of a - Al2O3. As the plasma spraying temperature is higher, the co-melting phenomenon occurred to some extent between the partly melten Al2O3 and mostly melten TiO2, and the Al2O3+TiO2 eutectic microstructure was formed. The fine mechanical bonding interface was formed between the coatings. The adoption of bonding bottom coating relieved stress flake phenomenon with the coatings.