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EN
The article presents the results of work on the verification of the technological capabilities of the EB-Dual BEAM device in the field of complex coatings, including gradient coating Ti↑-Zr↓, multi-pattern coating Ti-Zr, and multi-layer coating Ti/Ti-Zr/Zr. The obtained coatings were subjected to an analysis of changes in the chemical composition by the EDS method as a function of distance from the surface and observations of brittle fracture using scanning microscopy in order to analysis their internal structure. It has been shown that the use of two independent electron guns provides the ability to differentiate the chemical composition of two-component coatings independently from the character of these changes, i.e. linear changes, and step changes.
PL
W artykule przedstawiono wyniki prac dotyczące weryfikacji możliwości technologicznych urządzenia EB-Dual BEAM w zakresie wytwarzania powłok złożonych, w tym: gradientowych Ti↑-Zr↓, wieloskładnikowych Ti-Zr oraz wielowarstwowych Ti/Ti-Zr/Zr. Wytworzone powłoki poddano analizie zmian składu chemicznego metodą EDS w funkcji odległości od powierzchni oraz obserwacjom przełomów z wykorzystaniem mikroskopii skaningowej, w celu oceny ich budowy wewnętrznej. Wykazano, że wykorzystanie dwóch niezależnych dział elektronowych zapewnia możliwość różnicowania składu chemicznego powłok dwuskładnikowych niezależnie od charakteru tych zmian, tj. zmiany liniowe, zmiany skokowe.
EN
Chromium has been used for decades for the production of relatively thick, hard, wear resistant coatings in a wide range of industries — including the automotive and aircraft industry. Whilst traditional hard chromium finished coatings have no known health hazards, the chemicals, used in the process of application, comprise hexavalent chromium compounds (Cr6+ ions) and chromium in this state is extremely toxic. Due to the European directive on chemicals (REACH), hard chromium coatings, produced from highly toxic and carcinogenic baths, must be replaced by “green” solutions. In certain applications, the coatings obtained by PVD method can be the alternative to hard chromium electroplating where superior wear resistance to that of hard chromium electroplate is required — especially if a thin coating is suitable. Among PVD coatings, the chrome nitride coatings have demonstrated to possess excellent wear resistance properties. In this article was presented a fragment of research on this subject, carried out as part of an international research project CORNET, whose aim was to develop technologies of anti-wear and anti-corrosion coatings as replacements for hard chromium and cadmium coatings for applications in the aerospace and automotive industries. In particular, the article contains a description of the investigation of the mechanical properties of monolayer, gradient and multi-module coatings on CrN(C) base deposited with use of the cathodic arc evaporation CAE-PVD method on nitrided steel 42CrMo4 and additionally in the case of gradient and multi-module coatings on substrates of HS6–5–2 steel. The investigation includes the adhesion analysis by scratch test and by the Rockwell C indentation test (VDI — Verein Deutscher Ingenieure indentation test) tribomechanical analysis by pin–on–disc, measurement of friction coefficient and nanoindentation tests.
PL
W związku z europejską dyrektywą dotyczącą chemikaliów (REACH) twarde powłoki chromowe, produkowane w toksycznych i rakotwórczych kąpielach, muszą być zastąpione przez rozwiązania „zielone”. W niektórych zastosowaniach, między innymi w przemyśle lotniczym, powłoki otrzymywane metodą PVD mogą być alternatywą dla powłok z twardego chromu. Wokół tego problemu zogniskowano badania, których fragment opisano w artykule. Zasadniczym celem tych badań było porównanie właściwości tribomechanicznych powłok jednowarstwowych CrN oraz wielomodułowych i gradientowych CrN/CrCN osadzanych na azotowanych podłożach ze stali 42CrMo4 oraz dodatkowo w przypadku powłok wielomodułowych i gradientowych na podłożach ze stali HS6–5–2.
EN
The general topic of this paper is the computer simulation with use of finite element method (FEM) for determining the internal stresses of selected gradient and single-layer PVD coatings deposited on the sintered tool materials, including cemented carbides, cermets and Al2O3+TiC type oxide tool ceramics by cathodic arc evaporation CAE-PVD method. Developing an appropriate model allows the prediction of properties of PVD coatings, which are also the criterion of their selection for specific items, based on the parameters of technological processes. In addition, developed model can to a large extent eliminate the need for expensive and time-consuming experimental studies for the computer simulation. Developed models of internal stresses were performed with use of finite element method in ANSYS environment. The experimental values of stresses were calculated using the X-ray sin2ψ technique. The computer simulation results were compared with the experimental results. Microhardness and adhesion as well as wear range were measured to investigate the influence of stress distribution on the mechanical and functional properties of coatings. It was stated that occurrence of compressive stresses on the surface of gradient coating has advantageous influence on their mechanical properties, especially on microhardness. Absolute value reduction of internal stresses in the connection zone in case of the gradient coatings takes profitably effects on improvement the adhesion of coatings. It can be one of the most important reasons of increase the wear resistance of gradient coatings in comparison to single-layer coatings.
PL
Celem pracy było zbadanie różnic w stanach odkształceń własnych powstałych na skutek zadanych obciążeń mechanicznych w powłokach CrN/CrCN z gradientową warstwą przejściową pomiędzy CrN i CrCN. Powłoki zostały osadzone techniką PVD (Physical Vapour Deposition), metodą katodowego odparowania łukowego na podłożu ze stali 42CrMo4. Całkowita grubość osadzonych powłok wynosiła 8 μm, a gradientowa warstwa przejściowa pomiędzy CrN a CrCN miała grubość 2 μm. W modelu matematycznym warstwa gradientowa była reprezentowana przez tzw. funkcje przejścia opisujące przestrzenną zmianę parametrów materiałowych warstwy, takich jak: moduł Younga, współczynnik Poissona, współczynnik rozszerzalności cieplnej, granica sprężystości i moduł wzmocnienia. Rozważono dwa typy warstw gradientowych o różnych profilach zawartości węgla opisywanych przez funkcje potęgowe. Wykorzystując znajomość naprężeń własnych w powłokach po procesie osadzania (pomiar metodą dyfrakcji rentgenowskiej), wykazano na drodze symulacji numerycznych za pomocą MES różnice w stanach efektywnych odkształceń plastycznych powstałych na skutek obciążeń zewnętrznych. Pokazano na przykładzie, iż warstwy gradientowe reprezentowane przez potęgowe funkcje przejścia o wykładniku p > 1 cechują się mniejszymi strefami dużych odkształceń plastycznych na granicy działania obciążeń zewnętrznych w porównaniu z warstwami gradientowymi o p < 1. Wynika z tego, iż powłoki z warstwami gradientowymi mające p > 1 cechuje większa odporność na kruche pękanie.
EN
The aim of the study was to analyse differences in the states of internal deformation, caused by mechanical loads, in the coatings CrN/CrCN with a gradient transition layer between CrN and CrCN. The coatings were deposited using PVD technique (Physical Vapour Deposition) by cathodic arc evaporation on a substrate made from 42CrMo4 steel. The total thickness of the deposited coatings was 8 μm, and the gradient transition layer between CrN and CrCN had a thickness of 2 μm. In mathematical model, gradient layer was represented by the so called transition functions, describing the spatial change of the layer’s material parameters, such as Young’s modulus, Poisson ratio, coefficient of thermal expansion, yield strength and tangent modulus. In particular, were considered two types of gradient layers with different profiles of carbon concentration described by a power function. Using knowledge of the residual stress in the coating after the deposition process (measured by X-ray diffraction), has been shown by numerical simulation based on FEM, the differences in the states of effective plastic strain, caused by external loads. In particular, was shown on the example that the gradient layer represented by a power transition functions of the exponent p > 1 are characterized by smaller zones of high plastic strain on the boundary of applied external loads in comparison to the gradient layers with p < 1. This fact indicates, that the coatings with gradient layers with p > 1 are characterized by an larger fracture toughness.
PL
W pracy opisano zagadnienia dotyczące wykorzystania metod dylatometrycznych do celów badania właściwości termomechanicznych gradientowych powłok PVD. Badania zostały przeprowadzone na trzech rodzajach powłok CrCN/CrN różniących się charakterem zmian parametrów fizykochemicznych w gradientowej warstwie przejściowej, osadzonych na podłożu molibdenowym metodą katodowego odparowania łukowego. Zakres badań eksperymentalnych obejmował analizę zmian przesunięć fazowych między „wymuszeniem” cieplnym a „odpowiedzią” dylatometryczną systemu podłoże–powłoka PVD. Otrzymane wyniki eksperymentalne wskazują, że zaproponowana metoda badania zmian właściwości termomechanicznych systemów podłoże/gradientowa powłoka PVD umożliwia klasyfikację tych systemów ze względu na stabilność termiczną. Ponadto analiza zmiany przesunięcia fazowego Φ pomiędzy wydłużeniem podłoża systemu a jego temperaturą umożliwia badanie bezwładności termomechanicznej systemów.
EN
The paper describes the issues relating to the use of dilatometric methods for the study of thermomechanical properties of PVD gradient coatings. Tests were conducted on three types of coatings CrCN/CrN, differing in character of the change of physicochemical parameters in the gradient transition layer, deposited on molybdenum substrate by the method of cathodic arc evaporation. The scope of experimental studies included analysis of the changes of phase shifts between the thermal “extortion” and the dilatometric “response” of the substrate–PVD coating system. The experimental results indicate that the proposed investigation method of the change of thermomechanical properties of the system substrate/PVD gradient coatings allows the categorization of these systems from the point of view of thermal stability. In addition, analysis of the change of the phase shift Φ between the elongation of the substrate and the temperature enables the study of thermomechanical inertia of the systems.
EN
The main aim of the research is the investigation of the structure and properties of single-layer and gradient coatings of the type (Ti,Al)N and Ti(C,N) deposited by physical vapour deposition technology (PVD) on the cermets substrate. The structural investigations include the metallographic analysis on the transmission and scanning electron microscope. Examinations of the chemical compositions of the deposited coatings were carried out using the X-ray energy dispersive spectrograph EDS, and using the X-ray diffractometer. The investigations include also analysis of the mechanical and functional properties of the materials: substrate hardness tests and microhardness tests of the deposited coatings, surface roughness tests, evaluation of the adhesion of the deposited coatings as well as cutting properties. The results of the investigations carried out confirm the advantages of PVD coatings deposited onto cermets substrate especially in case of (Ti,Al)N. Coatings deposited onto the investigated substrates are characterised by good adhesion, high microhardness, taking effect in very high increasing of wear resistance. Deposition of hard, thin, gradient coatings on materials surface by PVD method features one of the most intensely developed directions of improvement of the working properties of materials. Equally important is the development of tool materials with respect to the fabrication of thin coatings resistant to wear in PVD process. It is of considerable importance, since through the selection of appropriate components, we can obtain a tool material of better properties. This area of tool material development is a priority nowadays, since it is the main route leading to the acquisition of machining tools of suitable properties. The results of the investigation provide useful information on microstructure, adhesion characterized in a scratch test, wear resistant properties of the gradient and single-layer coatings deposited onto cermet.
PL
Celem artykułu było zbadanie struktury i właściwości jednowarstwowych i gradientowych powłok typu (Ti,Al)N oraz Ti(C,N) naniesionych metodą fizycznego osadzania z fazy gazowej (PVD) na podłożu z cermetali narzędziowych. Badania strukturalne obejmują transmisyjną i skaningową mikroskopię elektronową. Analizę składu chemicznego i fazowego badanych powłok wykonano metodą spektroskopii energii rozproszonego promieniowania rentgenowskiego (EDS) oraz metodą dyfrakcji rentgenowskiej za pomocą dyfraktometru rentgenowskiego. Badania obejmują również analizę właściwości mechanicznych i funkcjonalnych badanych materiałów: badanie twardości podłoża z cermetalu i testy mikrotwardości naniesionych powłok, badania chropowatości powierzchni, ocena przyczepności naniesionych powłok, jak również właściwości skrawne. Wyniki przeprowadzonych badań potwierdzają zalety powłok PVD osadzanych na podłożu z cermetalu, zwłaszcza w przypadku powłok typu (Ti,Al)N. Powłoki osadzone na badanych podłożach charakteryzują się dobrą przyczepnością, wykazują wysoką mikrotwardość, co wpływa na wzrost odporności ściernej. Istoty jest rozwój materiałów narzędziowych w zakresie wytwarzania cienkich powłok odpornych na zużycie w procesie PVD. Ma to duże znaczenie, ponieważ wykorzystując cechy odpowiednio dobranych składników można uzyskać materiał narzędziowy o lepszych własnościach. Ta dziedzina rozwoju materiałów narzędziowych stanowi w obecnych czasach priorytet, ponieważ jest główną drogą, wiodącą do uzyskania narzędzi skrawających o odpowiednich własnościach. Wyniki przeprowadzonych badań dostarczają przydatnych informacji na temat mikrostruktury oraz adhezji, odpornych na zużycie gradientowych i jednowarstwowych powłok naniesionych na podłoże z cermetalu.
EN
The three-dimensional problem of elasticity concerning inhomogeneous half-space under normal and tangential loading applied in circular region was considered. The half-space is composed of the homogeneous body and double-layer coating which includes a homogeneous top coat and a gradient interlayer. The solution method is based on the two-dimensional integral Fourier transform. The influence of mechanical properties of coatings component and coefficient of friction on the first principal stress distribution was considered.
EN
A three-dimensional problem of the theory of elasticity for halfspace with multilayered coating with periodical structure is consid-ered. The fundamental layer consists of two layers with different thicknesses and different mechanical properties. The coating is described by the homogenized model with microlocal parameters. The solution is derived by using integral Fourier transform. Calculations were con-ducted with the assumption of elliptical distribution of normal and tangential tractions applied to the surface of the layered system in a cir-cular area. Analysis of the stresses was restricted to the first principal stress distribution.
PL
W pracy opisano procedurę polioptymalizacyjną wspomagającą dobór geometrii i własności materiałowych powłoki gradientowej TiAlN/TiN. W modelu matematycznym powłoka gradientowa jest reprezentowana przez tzw. funkcje przejścia, opisujące zmianę parametrów materiałowych warstwy przejściowej, takich jak moduł Younga, współczynnik Poissona, współczynnik rozszerzalności cieplnej oraz gęstość. Polioptymalizacja była prowadzona przy uprzednio zdefiniowanych ustalonych ciągłych obciążeniach zewnętrznych (tzw. obciążenia herzowskie), a przyjęte kryteria decyzyjne były funkcjami stanów naprężeń i odkształceń w powłoce i podłożu. Wykorzystując opracowaną procedurę polioptymalizacyjną, zostały określone optymalne wartości parametrów krzywizny funkcji przejścia pomiędzy warstwami TiAlN i TiN w powłoce gradientowej oraz zaproponowane zostały dwie metody analizy zbioru rozwiązań.
EN
In the paper polioptimization procedure of geometry and properties of TiA1N/ TiN gradient coatings was created. In the mathematical model gradient coatings were represented by transition functions. These functions are describing the change of layers materials' parameters, ie. Young's modulus, Poisson coefficient, thermal expansion coefficient and density. In the physical model used in polioptimization extemal loads were constant (herzian contact) and decisional criteria used in procedure were functions of the stresses and strains in the coating and substrate. Using created procedure optimal values of transition functions parameters were calculated. In addition two methods of analysis of solutions set were also described.
PL
W pracy rozwinięte zostały zagadnienia dotyczące wykorzystania metod termodylatometrycznych do celów projektowania i diagnostyki wielowarstwowych gradientowych powłok przeciwzużyciowych. Obiektem prowadzonych badań były powłoki gradientowe CrCN/CrN osadzone na podłożu ze stali szybkotnącej SW7M techniką PVD – metodą katodowego odparowania łukowego. Zakres badań obejmował analizę wpływu pobudzeń termicznych w systemach podłoże/powłoka gradientowa, prowadzonych na podstawie utworzonych termogramów diagnostycznych. W szczególności określony został związek pomiędzy zmianami wartości wprowadzonego ekwiwalentnego współczynnika rozszerzalności cieplnej po zadanych cyklach pobudzeń termicznych dla badanego systemu podłoże/powłoka gradientowa a poszczególnymi etapami wyżarzania. Ponadto określono wartości przemieszczeń liniowych podłoża wraz z osadzoną powłoką, będących wynikiem zadanych cyklów pobudzeń termicznych. Przeprowadzone badania wskazują na silny związek pomiędzy typem warstwy przejściowej a stanami naprężeń wewnętrznych w badanych systemach oraz stanowią informację o stanie przylegania powłoki do podłoża. Opracowana technika badań stanowi efektywną metodę diagnostyczną umożliwiającą ocenę stabilności termicznej w systemach podłoże/powłoka.
EN
The theme of paper are the issues concerning the use of thermodilatometric methods for the design and diagnostics of gradient multilayer antiwear coatings. The object of research were gradient coatings CrCN/CrN deposited by PVD technique on a high-speed steel HSS using cathodic arc evaporation method. Range of investigation included analysis of the influence of thermal loads on substrate/gradient coating systems, carried out under the created diagnostic thermograms. In particular, the dependence of changes of system’s relative equivalent thermal expansion coefficient as a function of annealing stages using created thermogram (graph of temperature changes) was determinated. In addition, the relationship between changes in the value of system’s substrate elongation as a function of annealing stages was also obtained. Research has indicated a strong correlation between the type of the transition layer, and the states of internal stress in the studied systems, and provide information about the state of adhesion of the coating to the substrate. The developed method is an effective diagnostic method that allows assessment of the thermal stability of the substrate/coating system.
11
Content available remote TEM microstructure investigations of aluminium alloys used as coating substrate
EN
Purpose: The aim of this paper was investigated structure and properties of gradient coatings produced in PVD process on AlSi9Cu aluminium alloys. Design/methodology/approach: The following results concern the structures of the substrates and coatings with the application of electron transmission and scanning microscopy; phase composition of the coatings using X-ray diffraction and grazing incident X-ray diffraction technique (GIXRD); microhardness and wear resistance. Findings: The deposited coatings are characterized by a single, double, or multi-layer structure according to the applied layers system, and the individual layers are coated even and tightly adhere to the substrate as well to each other. The analysis of coatings obtained on the surface of cast aluminium alloys by the PVD processes show a clear - over 100% - increase of the microhardness, compared to the base material microhardness. Practical implications: Achieving of new operational and functional characteristics and properties of commonly used materials, including the Al-Si-Cu alloys is often obtained by heat treatment, ie, precipitation hardening and/or surface treatment due to application or manufacturing of machined surface layer coatings of materials in a given group of materials used for different surface engineering processes. Originality/value: The paper presents the research involving the PVD coatings obtained on an unconventional substrate such as aluminium alloys. Contemporary materials should possess high mechanical properties, physical and chemical, as well as technological ones, to ensure long and reliable use. The above mentioned requirements and expectations regarding the contemporary materials are met by the non-ferrous metals alloys used nowadays, including the aluminium alloys.
12
Content available remote Strain field analysis in nanoindentation test of gradient coatings
EN
Purpose: In the paper strain distributions within TiAlN/TiN gradient coatings in nanoindentation test were analysed. The main goal was to examine the influence of the type of a gradient layer on strain distributions in the area of the indenter/coating. Design/methodology/approach: For physical modelling purposes Cr, TiN and TiAlN layers were treated as a continuous medium. Basing on this simplification for the mathematical description of the strain states in the coating a classical theory of stiffness was used. Gradient layers were modelled using the conception of transition function which describe continuous physico-chemical material parameters changes in each layer in the multilayer coating. The computer analysis of the strain fields in the coating after deposition process was done vie FEM method. Findings: For a chosen types of gradient coatings the strain distributions in the coating under external loads (nanoindentation test) were calculated. Using created examples of transition functions, the influence of the shape of the function on strain isolines in the area of the indenter/coating was examined. Research limitations/implications: The main simplification which was done during creation of the mathematical model was an assumption that the coating and the substrate are continuous media. This assumption causes that some physical effects occurring during experimental nanoindentation test can not be properly described in a computer model. Also there are numerous mathematical models of contact, so obtained numerical results (strain distributions) strongly depend of the postulated contact model. Practical implications: For a practical implications of the obtained results one should include a mathematical description of the strain states in the nanoindentation test of gradient coatings. The stress and strain fields analysis is extremely important in respect of fracture analysis. It should be also emphasis, that proposed mathematical description of gradient layer using transition function conception is an easy way to represent physical and chemical properties of gradient coating in computer models. The advantage of such a description of gradient layers can be used for example in polyoptimization process of multilayer gradient coatings. Originality/value: The main value of the paper is the comparison study of strain distribution in nanoindentation test of three different gradient coatings represented be three types of transition functions: (a) step function, (b) linear function and (c) modified non symmetrical sigmoidal function.
EN
Purpose: The main aim of the this research was the investigation of the microstructure, corrosion resistance and the mechanical properties of the nanocrystalline TiAlSiN, CrAlSiN, AlTiCrN and the gradient TiAlN, TiCN, AlSiCrN coatings deposited by cathodic arc evaporation technology onto the X40CrMoV5-1 hot work tool steel substrate. Design/methodology/approach: The surfaces’ topography and the microstructure of the investigated coatings were observed on the scanning electron microscopy. Diffraction and thin film structure were tested with the use of the transmission electron microscopy. The microhardness tests were made on the dynamic ultra-microhardness tester. Tests of the coatings’ adhesion to the substrate material were made using the scratch test. Findings: It was found that the microstructure of the nanocrystalline coatings consisted of fine crystallites, while their average size fitted within the range of 11-25 nm, depending on the coating type. The critical load LC2 lies within the range of 46-54 N. In case of the gradient coatings it was found that the microstructure consisted of crystallites while their average size fitted within the range of 25-50 nm, depending on the coating type. The coatings demonstrated columnar structure as well as good adhesion to the substrate. The critical load LC2 lies within the range 46-59 N. The coatings demonstrate a high hardness (40 GPa) and corrosion resistance. Practical implications: In order to evaluate with more detail the possibility of applying these surface layers in tools, further investigations should be concentrated on the determination of the thermal fatigue resistance of the coatings. The very good mechanical properties of the nanocrystalline and gradient coatings make them suitable in industrial applications. Originality/value: The investigation results will provide useful information to applying the nanocrystalline and gradient coatings for the improvement of mechanical properties of the hot work tool steels.
EN
Purpose Investigate the structure and properties of sintered tool materials, including cemented carbides, cermets and oxide ceramics deposited with single-layer and gradient coatings (Ti,Al)N and Ti(C,N), and to determine the dependence between the substrate type, coating material or linear variation of chemical composition and the structure and properties of the obtained tool material. Design/methodology/approach: Analysis of the structure (SEM, TEM), analysis of the mechanical and functional properties: surface roughness, microhardness tests, scratch tests, cutting tests. The Ti(C,N) and (Ti,Al)N gradient coating was investigated by XPS and AES method. X-ray qualitative phase analysis and the grazing incidence X-ray diffraction method (GIXRD) was employed to collect the detailed information about phase composition of investigated material’s surface layer. Computer simulation of stresses was carried out in ANSYS environment, using the FEM method and the experimental values of stresses were determined basing on the X-ray diffraction patterns. Findings Results of the investigation the influence of PVD coatings structure (single-layer or gradient) and kind on properties of coated tool materials. Coatings are characterized by dense, compact structure. The coatings were deposited uniformly onto the investigated substrate materials and show a characteristic columnar, fine-graded structure. The coatings deposited onto the investigated substrates are characterised by good adhesion and causes increasing of wear resistance. Gradient coatings are characterized by a linear change of chemical composition in the direction from the substrate to the coating surface. A more advantageous distribution of stresses in gradient coatings than in respective single-layer coatings yields better mechanical properties, and, in particular, the distribution of stresses on the coating surface has the influence on microhardness, and the distribution of stresses in the contact area between the coating and substrate has the influence on the adhesion of coatings. Practical implications: Deposition of hard, thin, gradient coatings on materials surface by PVD method features one of the most intensely developed directions of improvement of the working properties of materials. Originality/value: The grazing incidence X-ray diffraction method (GIXRD) and using the XPS and AES method in the investigated coatings were used to describe the gradient character of the coatings. The computer simulation is based on the finite element method, which allows to better understand the interdependence between parameters of process and choosing optimal solution.
15
Content available remote FEM modelling of internal stresses in advanced PVD coatings
EN
Purpose: The general topic of this paper is the computer simulation with use of finite element method (FEM) for determining the internal stresses of gradient and single -layer coatings (Ti,Al)N and Ti(C,N) deposited on the sintered tool materials, including cemented carbides, cermets and Al2O3+TiC type oxide tool ceramics by cathodic arc evaporation CAE-PVD method. Design/methodology/approach: Internal stresses’ models were performed with use of finite element method in ANSYS environment. The experimental values of stresses were were calculated using the X-ray sin2^ technique. The computer simulation results were compared with the experimental results. Microhardness and adhesion as well as wear range were measured to investigate the influence of stress distribution on the mechanical and functional properties of coatings. Findings: A more advantageous distribution of stresses in gradient coatings than in respective single-layer coatings yields better mechanical properties, and, in particular, the distribution of stresses on the coating surface has the influence on microhardness, and the distribution of stresses in the contact area between the coating and substrate has the influence on the adhesion of coatings. Practical implications: Deposition of hard, thin, gradient coatings on materials surface by PVD method features one of the most intensely developed directions of improvement of the working properties of materials. Presently the computer simulation is very popular and it is based on the finite element method, which allows to better understand the interdependence between parameters of process and choosing optimal solution. Originality/value: Nowadays the computer simulation is very popular and it is based on the finite element method, which allows to better understand the interdependence between parameters of process and choosing optimal solution. Influence of gradient structure of coatings on the mechanical and functional properties were investigated with use of finite element method.
16
Content available remote Gradient PVD coatings deposited on the sintered tool materials
EN
The paper presents investigation results of properties of the sintered tool materials: cemented carbides, cermets and Al2O3 type oxide tool ceramics with gradient (Ti,Al)N and Ti(C,N) coatings deposited with the cathodic arc evaporation CAE-PVD method.
17
Content available remote Ti(C,N) and (Ti,Al)N hard wear resistant coatings
EN
Purpose: Investigation the influence of kind of PVD coatings structure (homogenous or gradient) on properties of deposited tool materials: cemented carbides and cermets. Design/methodology/approach: Analysis of the structure, analysis of the mechanical and functional properties: surface roughness, microhardness tests, scratch tests, cutting tests. The Ti(C,N) gradient coating was investigated by XPS method with multifunctional PHI 5700/660 spectrometer. The characteristic of surface region coating were determined from XPS depth profile. X-ray qualitative phase analysis and the grazing incidence X-ray diffraction method (GIXRD) was employed to collect the detailed information about phase composition of investigated material’s surface layer. Microstructural of investigations substrates and coatings by transmission electron miocroscopy (TEM) were done. Findings: Results of the investigation the influence of PVD coatings structure (homogenous or gradient) and kind on properties of coated tool materials: cemented carbides and cermets are given in the paper. Coatings are characterized by dense, compact structure, there have been identified no pores, fractures and discontinuities. The coatings were deposited uniformly onto the investigated substrate materials and show a characteristic columnar, fine-graded structure. The results of roughness, microhardness and cutting tests confirm the advantages of the PVD coatings. The coatings deposited onto the investigated substrates are characterised by good adhesion and causes increasing of wear resistance. The grazing incidence X-ray diffraction method (GIXRD) in the investigated coatings were used to describe the structure and gradient character of the coatings. Practical implications: Deposition of hard, thin, gradient coatings on materials surface by PVD method features one of the most intensely developed directions of improvement of the working properties of materials. Originality/value: New techniques of gradient coatings deposition is one of the most spectacular aspect of the materials engineering development in the last years. The grazing incidence X-ray diffraction method (GIXRD) in the investigated coatings were used to describe the gradient character of the coatings.
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Content available remote Hard gradient (Ti,Al,Si)N coating deposited on composite tool materials
EN
Purpose: This paper presents investigation of gradient coating of (Ti,Al,Si)N deposited on the Al2O3+SiC(w) oxide ceramics substrate deposited with the PVD process. Design/methodology/approach: Structure of substrate and coating was investigated with use of scanning electron microscopy (SEM); The X-Ray Photoelectron Spectrometry (XPS) and Auger Electron Spectrometry (AES) examinations was carried out for proving the gradient character of the (Ti,Al,Si)N coating. The investigation includes also microhardness and roughness tests of the deposited coating and used substrate. Scratch test results was analysed to introduce adherence of the investigated coating. Findings: Gradient structure and main properties of the investigated materials were introduced. It has been stated, that properties of the coated with gradient (Ti,Al,Si)N coating oxide tool ceramic increase in comparison with uncoated material. Practical implications: Depositing the wear resistant gradient coating onto the Al2O3+SiC(w) oxide tool ceramic results in a significant increase of the surface layer microhardness, contributing most probably in this way in machining to the decrease of the wear intensity of cutting tools’ flanks made from the Al2O3+SiC(w) oxide tool ceramic. Originality/value: Gradient coatings are an innovative idea. The composition, microstructure and properties of gradient materials change continuously from the surface to the interior of the material.
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Content available remote Sintered tool materials with multi-component PVD gradient coatings
EN
Purpose: The main aim of researches was investigation of structure and properties of the (Ti, Al, Si)N gradient wear resistant coatings. Design/methodology/approach: The structural investigations include the metallographic analysis on the transmission and scanning electron microscope. Examinations of the chemical compositions of the deposited coatings were carried out using the X-ray energy dispersive spectrograph EDS, glow-discharge optical emission spectroscope GDOES, auger electron spectroscope (AES) and using the X-ray diffractometer. The investigations include also analysis of the mechanical and functional properties of the materials: substrate hardness tests and microhardness tests of the deposited coatings, surface roughness tests, evaluation of the adhesion of the deposited coatings as well as cutting properties. Findings: Deposition of the multicomponent gradient coatings with the PVD method, based on the Al and Si solid secondary solution in the TiN titanium nitride, isomorphous with the alternating pure titanium nitride TiN, on tools made from oxide, nitride ceramics and tool cermets, results in the increase of mechanical properties in comparison with uncoated tool materials, deciding thus the improvement of their working properties. Practical implications: Deposition of (Ti, Al, Si)N nanocrystalline coatings by the use of PVD method causes the increase of cutting properties of tools made of cermets for ca. 300% and of Al2O3+ZrO2 for ca. 100% comparing to adequately uncoated tools. Originality/value: Comparison of the wide range of modern sintered tool materials with wide unique set of PVD coatings.
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Content available remote Low friction and wear resistant coating systems on Ti6Al4V alloy
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Purpose: Development of an original multiplex hybrid treatment of Ti6Al4V alloy: diffusion hardening+intermediate hard gradient TiCxNy layer with use of continuous CAE+top low friction and wear resistant hard amorphous a-C layer with use of pulsed CAE method. Design/methodology/approach: Ti6Al4V substrates were diffusion hardened with interstitial O or N atoms with use of glow discharge plasma in the atmosphere Ar+O2 or Ar+N2. Next they were deposited with a hard gradient TiCxNy layer and with a hard amorphous a-C coating as the top one. The morphology, microstructure, chemical and phase composition, chemical bonds, microhardness and tribological properties during dry friction of the alloy after multiplex treatment have been investigated with use of SEM, EDS, XRD, XPS, Vickers diamond indenter and ball-on-plate test. Findings: An important increase of hardness of the near surface zone of the Ti6Al4V alloy has been achieved (from ∼ 350VHN to ∼ 1000 VHN), good adhesion between the gradient TiCxNy coating and the Ti6Al4V substrate as well as an important decrease of dry friction coefficient (down to ∼ 0.15) and a substantial increase of the resistance to wear (up to two orders of magnitude in comparison with non treated Ti alloy). Research limitations/implications: The research will be continued on greater number of specimens and against other counterbodies. Practical implications: It looks like that the Ti alloys can be used as mobile parts of machines due to high resistance to wear and low friction. Originality/value: A novel original multiplex hybrid treatment of Ti alloys has been developed at the Lodz University of Technology.
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