Preparation And Mechanism Of BaTiO₃Ceramics Coating For Remanufactured Parts

This paper aims to study the preparation process and mechanism of the Supersonic Plasma Spraying prepared BaTiO3coating. BaTiO3coating and PbTiO3coating was prepared on45steel matrix by the Supersonic plasma spraying equipment; Respectively, using scanning electron microscope (SEM), X-ray diffraction method (XRD), the microscopic hardness tester and Nanoindenter of detection coating morphology phase microhardness and nanomechanical properties; The grayscale method to measure the content of the coating porosity; By L9(34) orthogonal experiment method Analysis the BaTiO3coating orthogonal experiment to optimize the process parameters and porosity affect the basic mechanism of the dielectric properties; Using HYJH-3of piezoelectric material polarized apparatus polarization, and polarized dielectric properties of the coating were tested; Calculated BaTiO3powder melting process, the plasma temperature and BaTiO3phase transition relation.The results show that:(1)BaTiO3, PbTiO3ceramic coating process of exploration, drawn by Supersonic Plasma Spraying prepared BaTiO3coating dense tissue structure and lower porosity, good mechanical properties and dielectric properties.(2) Optimized by orthogonal experiment the BaTiO3spraying process, the results show that the optimal process parameters:spray distance of100mm, spraying current450A, argon flow3.2m3/h, voltage140V, in the process, the porosity of the coating was0.3%, the bonding strength between the coating and the substrate to57MPa, prepared under the process conditions and the coating mechanical properties superior to the conventional plasma spray.(3) Analysis of the voids in the polarization process of the coating of electron and ion during the movement in a different interface conduction process hindered, thus making its own dielectric constant decreased, and coating the presence of voids significantly impede electron and ionmove, similarly reduced the electric dipole moment per unit volume of, and thus lead to decline in the dielectric properties, the establishment of the basic mechanism of the porosity affect the dielectric properties.(4) Powder heating and heat transfer model and analysis calculation of the the plasma under22000K powder melting, further validation of the powder in the powder under the optimum process to fully melt.(5) For BaTiO3Powder, the the different plasma its phase transition effect relationship, and further illustrated by experimental verification plasma temperature greater impact when the high plasma temperature, the specimen prepared in the prone amorphous phase, when the plasmalower the temperature of the prepared coating quality is not high, so the appropriate spraying process a great influence on the phase transition of BaTiO3powders.