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1

Formation of coatings with technologies using concentrated energy stream

Radek Norbert, Kalinowski Artur, Pietraszek Jacek, Orman Łukasz J., Szczepaniak Marcin, Januszko Adam, Kamiński Janusz, Bronček Jozef, Paraska Olga

Production Engineering Archives

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2022

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Vol. 28, Iss. 2

117--122

EN

A number of modern surface processing methods use an energy flux. The examples include electro-spark deposition (ESD) and laser beam processing (LBP). The work concerns the study of Cu-Mo coatings deposited on C45 carbon steel, which were then eroded with a laser beam. The analysis included the analysis of the microstructure, measurements of macrogeometry and microhardness, corrosion resistance tests of selected areas after laser treatment. The coatings were applied with ELFA-541 and subjected to Nd:YAG laser treatment with variable laser parameters. The problem presented in the work can be used to extend the knowledge of the areas of application of ESD coatings, especially in sliding friction pairs.

2

Wpływ niejednorości powierzchniowych na przepływ w uczszelnianiu czołowym

Antoszewski B., Rokicki J.

Inżynieria Chemiczna i Procesowa

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2006

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T. 27, z. 3/1

889-899

PL

Przedstawiono wyniki analizy modelu przepływu przez szczelinę uszczelnienia czołowego z modyfikowanymi powierzchniami roboczymi. Model przepływu oparto na zmodyfikowanym równaniu Reynoldsa obejmującym również obszary kawitacji i oderwania filmu smarnego w okolicy wgłębień w powierzchni ślizgowej. Otrzymano równanie typu mieszanego eliptyczno-hiperbolicznego, a jego rozwiązanie uzyskano za pomocą technik numerycznych podobnych jak w przepływach transonicznych. Rezultatem modelowania jest przewidywanie radialnego wydatku masowego, a także precyzyjne oszacowanie sił działających na parę ślizgową.

EN

The fluid flow has been analysed in the clearance of a face seal with modified working surfaces. The model of flow used for this study bases on the Reynolds equation, appropriately modified to include the areas of cavitation and separation near grooves on the sliding surface. The equation is of mixed elliptic -hyperbolic type and can be solved by employing numerical techniques similar to those used for transonic flows (upwind finite difference schemes). The modelling helps to predict the radial mass flow rate as well as to assess accurately the forces acting on a sliding pair.

3

Wytwarzanie powierzchni niejednorodnych technologią elektroiskrową i laserową

Antoszewski B., Radek N.

Inżynieria Rolnicza

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2005

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R. 9, nr 2

23--30

PL

W artykule przedstawiono wyniki badań powłok Cu-Mo i Cu-Ti nakładanych elektroiskrowo, a następnie modyfikowanych wiązką laserową. Powłoki były nakładane na stal St3S. Badano mikrotwardość oraz makrogeometrię powierzchni powłok.

EN

The paper shows results of laser treatment of electro spark Cu-Mo and Cu-Ti coatings. The base material was mild steel. Microhardness and macrogeometry of the surface of layers was investigated.

4

Kinetics of random sequential adsorption of interacting particles on partially covered surfaces

Weroński P.

Bulletin of the Polish Academy of Sciences. Chemistry

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2003

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Vol. 51, No. 3-4

221-239

EN

The random sequential adsorption (RSA) approach was used to analyse adsorption kinetics of charged spheres at charged surfaces precovered with smaller sized, likely charged particles. The algorithm of M. R. Oberholzer et al. [20] was exploited to simulate adsorption allowing electrostatic interaction in three dimensions, that is, particle-particle and particle-surface interactions during the approach of a particle to the substrate. The calculation of interaction energies in the model was achieved with the aid of a many-body superposition approximation. The effective hard particle approximation was used for determination of corresponding simpler systems of particles, namely: the system of hard spheres, the system of particles with perfect sink model of particle-interface interaction, and the system of hard discs at equilibrium. Numerical simulations were performed to determine adsorption kinetics of larger particles for various surface concentration of smaller particles. It was found that in the limit of low surface coverage the numerical results were in a reasonable agreement with the formula stemming from the scaled particle theory with the modifications for the sphere-sphere geometry and electrostatic interaction. The results indicate that large particle-substrate attractive interaction significantly reduces the kinetic barrier to the large, charged particle adsorption at a surface precovered with small, likely charged particles.

5

Irreversible adsorption of colloids and proteins at heterogeneous surfaces

Adamczyk Z., Weroński P., Musiał E.

Bulletin of the Polish Academy of Sciences. Chemistry

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2002

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Vol. 50, No. 2

175-187

EN

Irreversible adsorption of colloid particles at heterogeneous surfaces was studied theoretically. In contrast to previous models, the dimension of the adsorption sites having the shape of circular discs, was comparable with the size of adsorbing spheres. Adsorption was assumed to occur if the sphere contacted the disc only. Numerical simulation of the Monte-Carlo type enabled one to determine particle flux, adsorption kinetics and jamming coverage as a function of the site density (coverage) and the size ratio particle/site, denoted by lambda . It was demonstrated that adsorption kinetics and the jamming coverage increased significantly, at a fixed site density, when lambda increased, i.e., for larger particle to site size ratio. It was also proven that the results derived from previous model elaborated for negligible site dimensions are valid only if lambda > 10.

6

Colloid adsorption at heterogeneous surfaces

Adamczyk Z., Siwek B., Jachimska B., Kowal A.

Bulletin of the Polish Academy of Sciences. Chemistry

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2002

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Vol. 50, No. 3

347-357

EN

Irreversible adsorption of colloid particles at heterogeneous surfaces was studied experimentally. The substrate of controlled heterogeneity was produced by covering mica sheets by colloid iron oxide (hematite) particles to a desired concentration. The particles of averaged diameter of 70 nm were produced by forced hydrolysis of FeCls solutions followed by a hydrothermal ageing. The coverage of colloid hematite particles (heterogeneity degree) was determined by electron microscopy and atomic force microscopy (AFM). Adsorption kinetics of polystyrene latex (averaged diameter 0.87Mim) at heterogeneous surfaces was studied by using the direct optical microscope observations in the impinging-jet cell. It was demonstrated that the initial adsorption rate attained the limiting value pertinent to homogeneous surfaces for heterogeneity degree of a few per cent. This behaviour was quantitatively interpreted in terms of the theoretical model considering the coupling between surface and bulk transport of particles. Similarly, the experimental results obtained for higher surface coverage of latex (long adsorption times) were in a good agreement with the random sequential adsorption (RSA) model.

7

Laser shaping of heterogeneous sliding surfaces of friction pairs.

Antoszewski Bogdan

Advances in Manufacturing Science and Technology

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2001

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Vol. 25, nr 3

19-29

EN

The paper is concerned with the applicability of laser technology to formation of heterogeneous surfaces in sliding friction pairs. The usability of local non-remelting hardening was emphasised. Another aim of the research was to evaluate the influence of local laser machining on the changes in structure and adhesion of plasma sprayed Al2O3, Cr2O3 and W2C coatings. It was established that local laser treatment of a W2C coating has a favourable influence on its adhesion to the substrate. The proposed technology can be applied to the production of elements of sliding friction pairs with heterogeneous surfaces.

PL

W pracy przedstawiono możliwości wykorzystania technologii laserowych do wytwarzania powierzchni niejednorodnych użytecznych w ślizgowych węzłach tarcia. W szczególności wykazano przydatność do tego celu procesu miejscowego hartowania bezprzetopnieniowego. Innym aspektem pracy była ocena wpływu lokalnej obróbki laserowej na zmianę struktury i przyczepność powłok z AL2O3, Cr2O3 i W2C natryskiwanych plazmowo. Stwierdzono korzystny wpływ lokalnej obróbki laserowej powłoki z W2C na jej przyczepność do podłoża. Proponowana technologia może mieć zastosowanie do wykonania elementów ślizgowych węzłów tarcia z powierzchniami niejednorodnymi.