The application of thermally sprayed coatings on CFRPs has gained great interest to enhance thermal and tribological properties and several processes have been optimized. However, for the coating of internal surfaces of tubes there is no sufficient technical solution. This paper introduces a novel and unique process technique for coating the internal surfaces of CFRP tubes using the transplantation of thermally sprayed coatings. A negative shape tube with defined surface and material properties was used as a mandrel and coated using atmospheric plasma spraying (APS). The CFRP was then produced using filament winding onto the coating, and after curing, the specimen was separated from the mandrel. With this process innovation, CFRP tubes with internal ceramic or metallic coatings can be produced without any thermal degradation of the polymeric matrix or damage to the carbon fibers. Compared to conventional coating methods, this novel process technique has several advantages. It allows for the production of internal coatings with low roughness of R z = 10 μm as sprayed without post-processing. The specimens also have a significantly lower tendency to corrode compared to conventional coated CFRPs. A high adhesion strength of the coatings of 15.9 MPa was achieved and the hardness of the internal ceramic coating is 918 HV0.1

In this study, coating buildup process of ceramic powder Al 2 O 3 deposited on steel substrate by atmospheric plasma spraying is simulated by creating a thermo-mechanical FEA model that utilizes the element death and birth techniques in ANSYS commercial software. The simulation process starts with side-by-side deposition of coarse subparts of the ceramic layer until the entire coating is created. Simultaneously, the heat flow into the material, initial quenching stress, thermal deformation and particle impact impulse transfer are computed. The purpose is to be able to predict - for the considered spray powder and substrate material - the development of residual stresses and to assess the risk of coating failure. The model allows the prediction of heat flow, temperature profile and residual stress development over time and position in the coating and substrate. The proposed model has been successfully run and results were experimentally verified by comparing with actual residual stresses measured by the hole drilling method.