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J. Zimmerman

Abstract

A numerical model based on the finite element method has been constructed with the aim to examine the residual stress state induced during thermal deposition of coatings on various substrates. The first stage of the modelling was designed to solve the problem of the high-velocity impact of a single spherical particle on a substrate using the “dynamics-explicit” module of the FEM ADINA software. In the second stage, the deposition process was simulated as a progressive growth of the coating until it achieved the desired thickness, and then the entire system was cooled to the ambient temperature. This problem was assumed to be thermo-mechanical and was also solved with the use of the FEM ADINA software. The samples assumed in the computations were cylindrical in shape and were built of a titanium coating, with three different thicknesses, deposited on an Al2O3 ceramic substrate by the detonation method. The numerical model was verified experimentally by measuring the deflection of the samples after their cooling. The computed values appeared to be in good agreement with those obtained experimentally.

Open access

T. Chmielewski, D. Golański, W. Włosiński and J. Zimmerman

Abstract

The paper is concerned with the metallization of ceramic materials using the friction-welding method in which the mechanism of the formation of a joint involves the kinetic energy of friction. The friction energy is directly transformed into heat and delivered in a specified amount precisely to the joint being formed between the metallic layer and the substrate material. The paper describes the ceramic metallization process, which has been developed by the present authors based on the friction-welding method.

The stress and temperature fields induced in the joint during the metallization process were determined using the finite element method with the aim to optimize the process parameters. The results were verified experimentally. The structures of the metallic coatings thus obtained were examined and the results are discussed in the paper.

Open access

J. Zimmerman, Z. Lindemann, D. Golański, T. Chmielewski and W. Włosiński

Abstract

There is described a method of modeling by the finite element method the residual stresses induced during thermal deposition of coatings. The simulation was performed in two stages. The first dynamic stage simulated the impacts of the individual particles of the coating material onto the substrate, and the next static stage included a non-linear thermo-mechanical analysis intended for simulating the process of layer-by-layer deposition of the coating, with a specified thickness, and then cooling the entire system to the ambient temperature. In the computations, the samples were assumed to be cylindrical in shape and composed of an Al2O3 substrate and a titanium coating (with three different thicknesses) deposited using the detonation method. The correctness of the numerical model was verified experimentally by measuring the deflections of a real Ti coating/Al2O3 substrate sample with the Ti coating detonation-sprayed on the ceramic substrate, after cooling it to the ambient temperature. The experimental results appeared to be in good agreement with those obtained by the numerical computations.