Structural FEM Analysis of Thermal Sprayed Coatings Under Conditions of Contact Pressure and High Temperature
State of art in the field of wear resistance indicate that, coatings produced with thermal spray methods, can significantly contribute to increase wear rate under conditions of wide range of sliding speeds and varying temperature values. In the beginning of this paper mechanical properties, manufacturing technology and possible applications of thermal sprayed coatings were reviewed. Mechanical properties for selected MMC (metal-matrix composites) materials applied for such coatings were introduced. Determining both stress and deformations of HVOF anti-wear coatings was necessary in order to estimate possible use of these coatings in application on machine parts exposed to high contact pressure and increased temperature. As well, relationship between different materials participation and mechanical properties of produced coatings were mentioned. Analysis method, model and boundary conditions were stated as method of experiment. Numerous structural FEM analysis were performed in order to determine stress and deformations in model samples under conditions of contact pressure and thermal conditions. High temperature was applied in prepared simulations to verify stress and deformation of samples caused by difference in base material and coating coefficient of thermal expansion. 3D structural simulations were conducted, in order to verify stress in different sections. Finite elements size and shape were optimized for obtaining possible short time of both mesh generation and solving of numerical problems. Contact pressure conditions were assumed as same for all simulations, for increasing result comparison possibilities. Analyses were performed for different geometry of samples, differing in coating thickness and surface curvature. Simulations of coatings on both round and flat surfaces were conducted in order to designate influence of surface curvature on coating stress under conditions of contact pressure and high temperature. Results of performed simulations were presented, including detailed information about stress in various direction, deformations and shear stress in area between base material and coating. Correlations between results and geometrical parameters of model were presented, especially including curvature and thickens of coating. Discussion of obtained results and recorded correlations was presented in last paragraphs of this paper. Authors find obtained results as useful initial data in further research on field of thermal sprayed coating application on machine parts exposed to high contact pressures.
KeywordsFEM Coefficient of thermal expansion Thermal spray Coatings
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