The paper presents an analysis of the efficiency of multi-component coatings based on metal nitrides of various thickness deposited using of the PVD method when turning of steels with coated cemented carbide. The research proves a positive influence of the tested coatings and their thickness on the tested characteristics such as the chip thickness compression ratio, shear angle, shear strain and mean coefficient of friction on the rake face Among others, they provide a decrease of the value of about and the value of 10%. In order to improve the cutting conditions, a proper selection of both types of coatings and their thickness depending on the processed material is necessary.
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Purpose: The paper presents investigation results of the structure and properties of the coatings deposited by cathodic arc evaporation - physical vapour deposition (CAE-PVD) techniques on the sialon tool ceramics. The Ti(B,N), Ti(C,N), (Ti,Zr)N, (Ti,Al)N and multilayer (Al,Cr)N+(Ti,Al)N, (Ti,Al)N+(Al,Cr)N coatings were investigated. Design/methodology/approach: The structural investigation includes the metallographic analysis on the scanning electron microscope. Examinations of the chemical compositions of the deposited coatings were carried out using the X-ray energy dispersive spectrograph EDS. The investigation includes also analysis of the mechanical and functional properties of the material: microhardness tests of the deposited coatings, surface roughness tests, evaluation of the adhesion of the deposited coatings and tribological test made with the „pin-on-disk”. Findings: Deposition of the multicomponent coatings with the PVD method, on tools made from sialon’s ceramics, results in the increase of mechanical properties in comparison with uncoated tool materials, deciding thus the improvement of their working properties. Practical implications: The multicomponent coating carried out on multi point inserts (made on sintered sialon’s ceramics) can be used in the pro-ecological dry cutting processes without using cutting fluids. However, application of this coating to cover sialon ceramics demands still both elaborating and improvement adhesion to substrates in order to introduce these to industrial applications. Originality/value: The paper presents some researches of multicomponent coatings deposited by PVD method on sialon tool ceramics
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Purpose: The aim of this paper is to investigate structure, mechanical and functional properties of sialon tool ceramics with wear resistant multicomponent coatings deposited with PVD method. Design/methodology/approach: The structural investigation includes the metallographic analysis on the scanning electron microscope. Examinations of the chemical compositions of the deposited coatings were carried out using the X-ray energy dispersive spectrograph EDS, and glow-discharge optical emission spectroscope GDOS. The investigation includes also analysis of the mechanical and functional properties of the material: microhardness tests of the deposited coatings, surface roughness tests, evaluation of the adhesion of the deposited coatings and tribological test made with the "pin-on-disk". Findings: Deposition of the multicomponent coatings with the PVD method, on tools made from sialon's ceramics, results in the increase of mechanical properties in comparison with uncoated tool materials, deciding thus the improvement of their working properties. Practical implications: The multicomponent coating carried out on multi point inserts (made on sintered sialon's ceramics) can be used in the pro-ecological dry cutting processes without using cutting fluids. However, application of this coating to cover sialon ceramics demands still both elaborating and improvement adhesion to substrates in order to introduce these to industrial applications. Originality/value: The paper presents some researches of multicomponent coatings deposited by PVD method on sialon tool ceramics.
Przedstawiono wyniki badań nad zachowaniem się w warunkach korozyjnych dwuwarstwowych metalicznych powłok wieloskładnikowych natryskiwanych cieplnie na stal St3S. Wytwarzano trzy rodzaje powłok różniących się składem warstwy zewnętrznej. Przeprowadzono badania strukturalne oznaczenia składu chemicznego stosowanych proszków, powłok po ich wytworzeniu i po procesie korozyjnym oraz analizę roztworów korozyjnych. Odporność na korozję w 0,1M zakwaszonym roztworze K2SO4 badano metodami elektrochemicznymi. Wykazano przydatność powłok do ochrony stali niskowęglowej w badanym środowisku.
EN
In this paper the results of the investigations of corrosion behaviour of bilayer thermal sprayed multicomponent coatings on St3S steel are presented. Three sorts of coatings having different chemical composition of the outer layer were produced. The investigations of the structure and chemical composition of the powders and coatings before and after corrosion test as well as chemical analysis of corrosion solutions were made. The corrosion resistance in 0,1M acid K2SO4 solution was determined. The usefulness of the above mentioned coatings was stated for corrosion protection of St3S steel in such conditions.
W pracy wykorzystano uogólniony model dyfuzji wzajemnej Darkena. Podstawą tego modelu jest stwierdzenie, iż strumień masy każdego ze składników to suma strumienia dyfuzyjnego i strumienia dryftu (unoszenia). Model zastosowano do badanego przypadku dyfuzji w 5-składnikowym układzie stop I powłoka. Odpowiednie warunki brzegowe oraz w zasadzie dowolne warunki początkowe pozwalają na badanie procesów dyfuzji wzajemnej w stopach wieloskładnikowych, np. będących wynikiem obróbki powierzchniowej, termicznej i/lub korozji. Model w szczególności umożliwia przewidywanie zmiany składu utlenianego stopu w warstwie przypowierzchniowej - są to zmiany powstałe w wyniku jego reakcji z otaczającą atmosferą. Co więcej, zaprezentowano równania opisujące proces dyfuzji wzajemnej w ogólnym przypadku, w którym współczynniki dyfuzji składników są funkcją składu, oraz w przypadku, kiedy zachodzą reakcje chemiczne na granicy(ach) pola dyfuzji (dyfuzja wzajemna w układzie otwartym).
EN
The incorporation of Pt in aluminide coatings is known to be effective in improving the high temperature thermal stability and the corrosion resistance of superalloys. The effect of Pt on the diffusion of elements in Pt-aluminide coatings on MAR M002 alloys has been studied at 1173 and 1273 K for various annealing times. The calculated uphill diffusion concentration profiles in the coating/alloy system together with experimental results are presented. The generalized Darken model of interdiffusion has been used in this work. The model stipulates that the total mass flow comprises diffusion and drift fluxes. It is applied in the case of diffusional transport in the 5-component alloy I coating system. The proper boundary conditions make it possible to study interdiffusion in multicomponent alloys, complex coatings and open systems, e.g., the evolution of the alloy composition due to oxidation (concentration profiles in beta-NiAl(Pt) beneath a growing alumina scale. The relaxed initial conditions also allow us to study interdiffusion in non-regular initial conditions. Moreover, the equations describing the interdiffusion processes in the general case where the components' diffusitives vary with composition and the reactions of diffusing components within the diffusion zone are described.
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