Stereometric and Tribometric Studies of Polymeric Pin and Ceramic Plate Friction Pair Components

Two complementary approaches should be used for the full characterisation of friction pair components. The first approach consists of stereometric studies of machined as well as worn surface topography of the friction components with multiple measurement methods used. The second approach, tribometric studies, enables the tribological characteristics of the friction pair. This work presents the complete characterisation of polymeric pin and ceramic plate friction pair components based on studies with the use of three research instruments: an interference microscope, a scanning electron microscope and a tribological tester. The results of the studies showed that the same treatment conditions used for different but similar ceramic materials did not provide exactly the same characteristics of both the machined and worn surface topography. Moreover, the results showed that the material properties and machined surface topography of the ceramic component significantly affected the friction coefficient and linear wear as well as the wear intensity of the polymeric component. Connecting the two approaches, stereometric studies and tribometric studies, allowed for a better identification of the wear mechanism of the polymeric pin (i.e., abrasion, fatigue and adhesion wear) and the kind of wear products (polymeric material)

Koncepcja metodyki badań topografii powierzchni – badanie i analiza tribologicznych śladów zużycia

The methodology of surface topography research plays a key role in identifying and describing the wear mechanism, including the tribological wear traces. In the published literature, wear traces are most often described based on the surface morphology created in the operation process (microscopic image – optical microscope OM, scanning electron microscope SEM, atomic force microscope AFM); less frequently used are 2D profile description (contact or non-contact profilometer) or 3D topography (profilometer, confocal microscope, interference microscope, focus variation microscope). Each method of testing the worn surface has its own characteristics and purposefulness of use. The combination of different methods enables a comprehensive assessment of the surface topography created in the operation process and the characterisation of tribological wear traces.This work presents the main issues in the range of research methodology of the surface topography created in the operation process (operated/worn surface topography) – the purpose of research, research programme, research methods and tools, analysis of research results (quantitative – parametric and qualitative – non parametric). The research methodology of the surface topography and tribological wear traces is presented on selected examples. The method of conducting a comprehensive analysis, including all elements – surface morphology, 2D profile analysis and 3D topographic analysis – is discussed.Metodyka badań topografii powierzchni odgrywa kluczową rolę w identyfikowaniu i opisie mechanizmów zużycia, w tym śladów zużycia tribologicznego. W publikowanych pracach najczęściej identyfikacja śladów zużycia przeprowadzana jest na podstawie morfologii powierzchni eksploatowanej (obraz mikroskopowy – mikroskop optyczny OM, skaningowy mikroskop elektronowy SEM, mikroskop sił atomowych AFM), rzadziej stosowane są opisy profilu 2D (profilometr stykowy lub bezstykowy) czy topografii 3D (mikroskop konfokalny, mikroskop interferencyjny, mikroskop różnicowania ogniskowego). Każda z metod badań powierzchni eksploatowanej ma swoją charakterystykę oraz celowość zastosowania. Połączenie różnych metod umożliwia kompleksową ocenę powierzchni eksploatowanej oraz charakterystykę śladów zużycia tribologicznego. W niniejszym opracowaniu przedstawiono główne zagadnienia w zakresie metodyki badań powierzchni eksploatowanej – cel badań, program badań, metody i narzędzia badawcze, analiza wyników badań (ilościowa – parametryczna oraz jakościowa – nieparametryczna). Metodykę badań powierzchni eksploatowanej i śladów zużycia tribologicznego zaprezentowano na wybranych przykładach. Omówiono sposób przeprowadzenia kompleksowej analizy, obejmującej wszystkie elementy – morfologię powierzchni, analizę profilową 2D oraz analizę topograficzną 3D

Stereometric and Tribometric Studies of Polymeric Pin and Ceramic Plate Friction Pair Components

Two complementary approaches should be used for the full characterisation of friction pair components. The first approach consists of stereometric studies of machined as well as worn surface topography of the friction components with multiple measurement methods used. The second approach, tribometric studies, enables the tribological characteristics of the friction pair. This work presents the complete characterisation of polymeric pin and ceramic plate friction pair components based on studies with the use of three research instruments: an interference microscope, a scanning electron microscope and a tribological tester. The results of the studies showed that the same treatment conditions used for different but similar ceramic materials did not provide exactly the same characteristics of both the machined and worn surface topography. Moreover, the results showed that the material properties and machined surface topography of the ceramic component significantly affected the friction coefficient and linear wear as well as the wear intensity of the polymeric component. Connecting the two approaches, stereometric studies and tribometric studies, allowed for a better identification of the wear mechanism of the polymeric pin (i.e., abrasion, fatigue and adhesion wear) and the kind of wear products (polymeric material)

Assessment of Free-Form Surfaces’ Reconstruction Accuracy

The paper presents the problem of assessing the accuracy of reconstructing free-form surfaces in the CMM/CAD/CAM/CNC systems. The system structure comprises a coordinate measuring machine (CMM) PMM 12106 equipped with a contact scanning probe, a 3-axis Arrow 500 Vertical Machining Center, QUINDOS software and Catia software. For the purpose of surface digitalization, a radius correction algorithm was developed. The surface reconstructing errors for the presented system were assessed and analysed with respect to offset points. The accuracy assessment exhibit error values in the reconstruction of a free-form surface in a range of ± 0.02 mm, which, as it is shown by the analysis, result from a systematic error

Koncepcja metodyki badań zaawansowanych systemów tribologicznych

The conduct of research on advanced tribological systems in order to determine the best solutions in terms of the durability and reliability of technical objects containing these systems requires a multifaceted and comprehensive approach due to the complexity of tribological processes occurring during operation. Observation of these processes is complicated and limited due to the inaccessibility of the friction zone. Therefore, progress in improving tribological characteristics is mainly determined by developing laboratory test methods. From the point of view of describing the tribological properties of the surface layer, the geometric structure of the surface (shape, waviness, roughness and surface defects), the structure of the physicochemical zones (microstructure, mechanical properties, physicochemical properties), and the ability to properly interact with the lubricant should be taken into account. Studies of advanced tribological systems should therefore include two complementary test methods, i.e., friction wear tests and surface layer tests (as manufactured and as operated). This paper presents a concept for research on advanced tribological systems and a justification for conducting complementary research on these systems, referring to selected examples (processing tools, joint implants, and dental implants). The research results are examples which illustrate the essence of conducting complementary research.Prowadzenie badań zaawansowanych systemów tribologicznych w celu określenia najlepszych rozwiązań pod względem trwałości i niezawodności obiektów technicznych zawierających te systemy wymaga wielowątkowego i kompleksowego podejścia ze względu na złożoność procesów tribologicznych zachodzących podczas eksploatacji. Obserwacja tych procesów jest skomplikowana oraz ograniczona z uwagi na niedostępność strefy tarcia. Dlatego postęp w poprawianiu charakterystyk tribologicznych determinowany jest głównie przez rozwój metod badań laboratoryjnych. Z punktu widzenia opisu właściwości tribologicznych warstwy wierzchniej należy brać pod uwagę zarówno strukturę geometryczną powierzchni (kształt, falistość, chropowatość i wady powierzchni), strukturę fizykochemicznych stref (mikrostruktura, właściwości mechaniczne, właściwości fizykochemiczne)oraz zdolność do właściwej interakcji ze środkiem smarowym. Badania zaawansowanych systemów tribologicznych powinny zatem obejmować dwie komplementarne metody badawcze, tj. badania tarciowo-zużyciowe oraz badania warstwy wierzchniej (wytworzonej i eksploatowanej). W pracy przedstawiono koncepcję badań zaawansowanych systemów tribologicznych oraz zasadność prowadzenia komplementarnych badań tych systemów, odnosząc się do wybranych przykładów (narzędzia obróbcze, implanty stawów, implanty stomatologiczne). Wyniki badań stanowią przykłady pokazujące istotę prowadzenia badań komplementarnych

Charakterystyka właściwości funkcjonalnych powierzchni obrobionej na podstawie nieparametrycznego i parametrycznego opisu topografii

The shaping of the functional properties of the surface of an object in a technological process plays a key role in the later operation of this object. The paper presents the results of the tests performed on the surface topography of objects made of a selected hard-to-machine material, i.e., titanium alloy. Two measuring devices were used in the research, an interference microscope, and a scanning electron microscope, which enabled the comprehensive (non-parametric and parametric) description of surface topography obtained for three different finishing parameters. It was noted that, in addition to material properties, in the evaluation of the functional properties of a surface, it is important to carry out not only the qualitative, but also quantitative analysis of the machined surface topography.Kształtowanie właściwości funkcjonalnych powierzchni przedmiotu w procesie technologicznym odgrywa kluczową rolę w późniejszym procesie eksploatacji tego przedmiotu. W pracy przedstawiono wyniki ba¬dań topografii powierzchni przedmiotów wykonanych z wybranego materiału trudnoskrawalnego – stopu tytanu. W badaniach wykorzystano dwa urządzenia pomiarowe – mikroskop interferencyjny i skaningowy mikroskop elektronowy, co pozwoliło na kompleksowy (nieparametryczny i parametryczny) opis topografii powierzchni obrobionej otrzymanej dla trzech zabiegów ściernej obróbki wykończeniowej. Zauważono, że poza własnościami materiałowymi, w ocenie właściwości funkcjonalnych powierzchni istotna jest analiza topografii powierzchni obrobionej zarówno pod względem jakościowym, jak i ilościowym

Investigation of the Surface Topography of Titanium Alloys Applied to Friction Components

The subject of this study and analysis was titanium alloy, applied among others to the friction components of orthopaedic (artificial hip joint) implants. This material was subjected to abrasive finishing using a synthetic diamond as a tool. The properties of the studied titanium alloy were characterised. The processing technology and the research methods are discussed. The surfaces, after being subjected to abrasive machining, were studied using three research instruments – an interference microscope, a scanning electron microscope, and an atomic force microscope. Advanced metrology software was used to analyse the measurement data. The aim of the research was to present the changes taking place in the forming of the surface of the studied titanium alloy, in particular those occurring in the final sequential processing. A characterisation of the machined surfaces was prepared based on parametric (surface topography – parameters and functions) and non-parametric (surface morphology – images) analysis. The significant influence of the sequence and the tool (diamond grain and micro-grain) on the surface topography shaped during the technological process is presented. Improvement in the surface quality and features was observed. Parametric analysis showed no significant differences between TA-III and TA-IV surfaces, while these differences were visualised by non-parametric analysis. Moreover, the hereditary features of the surface topography (isotropy and pits/valleys) and their influence on the potential functional properties (place/area for accumulation/retaining of the lubricant in the friction zone) of the titanium alloy were analysed

Surface Topography and Tribological Properties of Cutting Tool Coatings

The surface topography formed during the technological process has an influence on the wear characteristics and modifies the surface topography of friction components during the operation process, including cutting tools. It is therefore important to carry out research to find the best material and construction solutions to increase their durability and reliability. The research and analysis covered selected coatings (TiN, TiCN, TiAlN) applied to cutting tools for their anti-wear properties. The coatings were obtained through physical vapour deposition PVD. For the purpose of evaluating the tribological properties of the coatings, friction-wear tests were carried out in rotary motion on a ball-on-disc device (ball made of 100 Cr6 steel, discs made of SW7M steel coated with selected coatings) at a constant load (10N), under coolant lubrication conditions. Investigations of the surface topography before and after tribological tests were carried out on a confocal microscope. The friction coefficient and the amount of wear (wear track) of the coatings were shown to vary under the same operating conditions. The highest friction coefficient was obtained for the TiCN coating (0.199), while the lowest for the TiN coating (0.144) – the surface topography of the balls deteriorated (parameters Sq, Sz, Ssk, Sku increased in value). The highest linear wear (281.1 µm) was obtained for the TiAlN coating (the coating was torn halfway through the test), where the ball surface topography has improved (lowered values of parameters Sq, Sz, Ssk, Sku, Spd, Spc)