Obtenção e caracterização de revestimentos compósitos Al2O3-13%pTiO2 /liga a base de níquel obtidos por aspersão térmica a chama convencional

Abstract

Ceramic coatings obtained by thermal spray are known by increase superficial mechanical proprieties, like hardness, wear and corrosion resistance. These coatings have large application in aeroespace, oil and automotive, highlighting here your performance as thermal barrier, also known like - Thermal Barrier Coatings (TBC’s). Despite finding great application these coatings present low ductility compromising the life of the coating. The conventional flame thermal spray technique is notable for the low cost and simplicity of handling. Usually composite powders have low adhesion to the substrate, to improve adhesion, metal alloys are used for bonding to the substrate. As an alternative to obtain a better adhesion coating and to maintain the thermal barrier capacity, in this work were developed composite coatings of Al2O3-13%pTiO2 /NiAlMoB. The mechanical properties of the coatings were analyzed by folding, adhesion and microhardness tests. The microstructural analysis was performed by X-ray diffraction, metallography and analysis of the thickness of the sprayed layer. The thermal insulation was evaluated by thermal conductivity test. The results indicate that the coatings obtained with the composition containing 50% NiAlMoB alloy have good thermal and mechanical properties when compared to the coating conventionally obtained using 100% Al2O3-13%pTiO2.