Study the correlation between film deposition processes and the tribological properties of the resultant coatings

Abstract

The project aims to study the correlation between film deposition processes and the tribological properties of the resultant coatings. The coatings will be made through PVD or plasma nitriding, as well as through combined processes carried out by means of a P APVD technique for obtaining duplex coatings. The assessment of the quality of the coatings will be based on their mechanical properties (strength and toughness), microstructure features, adhesion to the substrate and behavior in tribological pairs. The study will be focused on the following subjects: deposition processes of duplex coatings (plasma nitriding and PAPVD- TiN) on H13 and D2 tool steels, formation of expanded austenite and martensite in austenitic and martensitic stainless steels, formation of duplex coatings (plasma nitriding and P APVD- TiN), deposition process of stabilized zirconia on high speed steels (thermal barrier) and the behavior of zirconia coated high speed steels when submitted to thermal fatigue. The microstructure characterization of the coatings will be conducted by atomic force microscopy, scanning electron microscopy, X-ray EDS, GDOS microanalysis, X-ray difractometry. The mechanical properties of the coatings will be assessed by nanoindentation, instrumented linear sclerometry, macroscopic indentation and X-ray diffraction (residual stresses). The tribological behavior of the coatings will be assessed by means of machining tests (NCM device), instrumented pendular scratch tests and microabrasion tests. The thermal fatigue behavior of the coated high speed steel will be evaluated through properly designed equipment (inductive heating and water cooling). Mathematical modeling of the coating stresses will be carried out through Finite Element Analysis (FEM). The results will be used to evaluate the suitability of the previous test assembly and processes parameters, which can lead to another set of experiments and subsequent assessment. This iterative method will allow establishing the basic conditions for optimizing the performance of coated components. (AU)