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PL
W artykule zaprezentowano współczesne maszyny wytrzymałościowe i przyrządy pomiarowe do badania właściwości mechanicznych materiałów. Zamieszczono oraz omówiono ich schematy ideowe, zalety, wady, ograniczenia i zastosowanie. W przypadku niektórych z nich przedstawiono literaturowe i własne wyniki z badań doświadczalnych.
EN
The paper reports modern testing machines and measuring instruments used to examine mechanical parameters of materials. Their schematic diagrams, advantages and disadvantages, limitations and applications are discussed. Selected already published results of tests and those achieved by the Authors are presented.
PL
W pracy zaprezentowano wybrane efekty strukturalne i mechanizmy uszkodzenia, występujące w materiałach konstrukcyjnych na skutek różnych rodzajów obciążenia. Omówiono aktywowanie systemów poślizgu oraz powstawanie różnych rodzajów podstruktur dyslokacyjnych podczas deformacji na skutek proporcjonalnych i nieproporcjonalnych ścieżek obciążenia. Przedstawiono mechanizmy rozwoju uszkodzeń powodowane plastycznym płynięciem na zimno i gorąco, powolnym odkształcaniem o charakterze nadplastycznym oraz pełzaniem. Zamieszczono ich rzeczywiste przykłady w postaci obrazów mikroskopowych, sposoby modelowania i opisywania z wykorzystaniem równań o charakterze fenomenologicznym.
EN
The paper presents structural effects and damage mechanisms in engineering materials caused by different types of loading. Activation of slip systems, generating different dislocation substructures taking place during deformation along proportional and nonproportional loading paths are discussed. Moreover, mechanism evolution of damage during: cold and hot plastic flow, slow plastic deformation of superplastic type and creep are shown. Typical examples of damage in form of microscopic patterns, methods of their modeling and theoretical approaches based on phenomenology of material effects are described.
3
PL
Dobór optymalnego materiału dla nowoprojektowanego wyrobu odgrywa jedną z kluczowych ról w procesie projektowania inżynierskiego. Poprawnie wyselekcjonowany materiał pozwala na efektywne wykorzystanie dostępnych w produkcji środków technologicznych, jednocześnie zapewniając sprostanie wymaganiom funkcjonalnym wyrobu w połączeniu z ekonomiczną zasadnością produkcji. W niniejszej pracy przedstawiono metodę optymalizacji procesu doboru materiału. Przedstawiona metoda charakteryzuje się intuicyjnością stosowania, oraz możliwością zalgorytmizowania, która pozwala na łatwe stworzenie narzędzia pomocnego konstruktorowi w jego codziennej pracy.
EN
Selection of the optimum material for the newly designed product plays a key role in the process of engineering design. Correctly selected material allows for efficient use of available resources in the production technology, while providing a product to meet the functional requirements in conjunction with the legitimacy of economic production. This paper presents a method of optimizing the material selection process. The presented method is characterized by intuitive use, and the possibility algorithmisation, which allows to easily create a helpful tool in the designer's everyday work.
4
Content available remote Hard coal modified with silanes as polyamide filler
EN
Purpose: This paper shows the influence of coupling agents, especially silanes, on mechanical properties of polyamide 6 filled with hard coal dust. Design/methodology/approach: Before preparing compositions, pulverised filler surface was modified with coupling agents. Then, it was compounded using a twin-screw extruder composite consisting of modified hard coal and polyamide 6. A blend was granulated later and test samples were subjected to injection moulding. Afterwards, mechanical properties were evaluated. These properties have essential meaning for applications of new composites as structural materials. Findings: Tests demonstrated that modification of powdered hard coal surface with coupling agents had not significant effect on mechanical properties of polyamide/hard coal composites. Research limitations/implications: Applied compounding procedure did not allow to achieve good compositions homogenisation. A new method to be applied is planned in future research. Simultaneously, it is necessary to investigate composites with other coupling agents which will improve filler’s adhesion to a polymer. Long-term test are also planned. Practical implications: Hard coal, cheap and widely available filler, used to modify thermoplastic polymers, enable to obtain new materials with attractive properties and many applications. Originality/value: Paper represents innovative polymer filler and methods to modify it.
5
Content available remote Morphological aspect of multilaminar PP composite
EN
Purpose: Analyzing and observing the obtained multi-laminar structure of polymer nanocomposites performed by non-conventional technique of injection moulding. Design/methodology/approach: Basing on DOE conventional technique was evolved and fitted out with additional mould externally operated by computer and pressure machine (generating 150 bar hydraulic pressure). Findings: Chosen method brings advantage of final highly developed and reinforced structure during manufacturing. Research limitations/implications: Polymer-layered silicate and silica nanocomposites are nowadays very important engineering materials showing their noticeable impact among composites. Practical implications: Nanocomposites with created layered structure on nano and micro level are undoubtedly high performance engineering materials with promising growth and with continuous interests and developing branch in science and industry. Originality/value: Non-conventional technique allows for the manipulation through reversing of the melted polymer and polymer blends while the cooling phase starts, creating self-reinforced polymer composite.
6
Content available remote Investigation of processing properties of polyamide filled with hard coal
EN
Purpose: The aim of this article is to present the influence of contents and kind of hard coal used as powder filler on rheological properties (viscosity) of polyamide 6. Design/methodology/approach: Preparation of composite of polyamide 6 with hard coal was carried out on laboratory twin screw extruder. Extruded composite was granulated and in this form was used for MFR analysis. Taking into account MFR results viscosity was calculated. The influence of filler content on viscosity was next searched. Findings: Results of research showed that addition of powdered hard coal to polyamide 6 matrix cause pronounced decrease of MFR index. In this way significant increase of viscous flow was observed. It is often observed phenomenon for polymer composite filled with powder materials. Research limitations/implications: It is necessary to carry out the research with surface modified hard coal with coupling agents which provide better adhesion of polymer matrix to filler. Practical implications: Hard coal used as a filler in composites makes it possible to gain new and cheaper polymeric materials with many possible applications. Originality/value: Investigation described in article shows possibility of hard coal application as innovatory filler of polymers. The influence of this filler on rheological properties indicate that processing of these new materials may be accompanied with some problems.
PL
W artykule przeanalizowano przykładowe projekty niestandardowych próbek stosowanych w badaniach materiałów konstrukcyjnych, w tym próbek rurkowych używanych w badaniach plastycznego płynięcia, próbek wykorzystywanych w badaniach procesu pełzania oraz minipróbek, które są w szczególności przeznaczone do badań mających na celu określenie właściwości mechanicznych połączeń spawanych. Omówiono także charakterystyczne cechy geometryczne wybranych typów próbek, mające istotny wpływ na dokładność wyników badań doświadczalnych. Pokazano, jakie są zasadnicze różnice między próbkami o wymiarach standardowych a próbkami wykonanymi w skali 1:5. Ponadto, w przypadku próbek stosowanych w badaniach pełzania, zwrócono uwagę na rolę kołnierzy w kształtowaniu jednorodnego rozkładu naprężeń w strefie pomiarowej próbki. W podsumowaniu podano wytyczne dotyczące poprawnego projektowania próbek zarówno o wymiarach standardowych, jak i minipróbek.
EN
In this paper non-standard specimens applied in the strength tests of engineering materials are presented. Moreover, the paper presents the geometries of thin-walled specimens used in investigations of the plastic flow, specimens applied in creep tests and mini-specimens, which are very useful in determination of mechanical parameters of weld connections. The characteristic properties of the specimen geometry are presented. They have a significant influence on the accuracy of experimental results. The paper also shows the principal differences between the standard specimens and the mini-specimens. An influence of the circumferential protrusions of creep specimens on the homogenous stress distribution is discussed. The paper shows the guidelines for the correct designing of standard and mini-scale specimens.
EN
Photochemical machining (PCM) is one of the important nontraditional machining processes in which photographic and chemical etching techniques are employed. The workpiece material is shaped by using a strong chemical solution to dissolve surface of the workpiece that was selectively exposed to machine areas using a photographic technique. The application of photochemical machining has increased extensively in the electronics, precision engineering, medical and decorative industries as well as in the microcomponentproduction industry. The present study is aimed to provide information on the application of PCM. The selection of etching parameters such as etchants for engineering materials, chemical additives into main etchants and etching temperature on the different machining outputs will be discussed. Also, the influences of environmental legislations on the machining process are examined and the future directions are considered.
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