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1

Investigation of processing properties of polyamide filled with hard coal

Stabik J., Suchoń Ł., Rojek M., Szczepanik M.

Journal of Achievements in Materials and Manufacturing Engineering

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2009

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Vol. 33, nr 2

142-149

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.

2

Influence of the method of heating/cooling moulds on the properties of injection moulding parts

Postawa P., Kwiatkowski D., Bociaga E.

Archives of Materials Science and Engineering

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2008

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Vol. 31, nr 2

121-124

EN

Purpose: The main purpose of carry out research was estimate the influence thermal conditions of the mould on properties of injection moulded parts. Design/methodology/approach: The properties of structure and mechanical properties of injection moulding parts were determined by many factors. One of them is thermal conditions of tool. Injection mould can be heated or cooling during the process and its depend which kind of polymer we produced and what properties we going to obtain. A few different cooling mould systems were presented in the article and disadvantages and advantages of each of them. Findings: The impact of thermal condition (cooling rate, mould temperature) on the structure and physical properties of injection moulded parts were present. Research limitations/implications: Research was limited to a few thermoplastics polymers. Practical implications: Received and presented results are useful from the point of the view of industrial applications and they are able to contribute to improvement parts obtained using injection moulding technology. Originality/value: Very original microscopic research carry out during cooling stage of polymer and crystallization process.

3

Inoculation of primary structure of pure aluminium

Szajnar J., Wróbel T.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 20, nr 1-2

283-286

EN

Purpose: The main aim of studies was to determine common influences on EN AW-A199,5 structure refinement of reverse or impulse reverse magnetic field and small amount of inoculants sort AlTi5B1, AlZr5 and AlV10 - less than obligatory standard PN-EN 573-3 (concerning about aluminium purity). Design/methodology/approach: Factor variables of founding were: pulse frequency of magnetic field (f), magnetic induction (B), time of magnetic field action (t) and inoculant quantity (M). Degree of fineness was represented by equiaxed crystals zone content (SKR) on cylindrical castings cross-section of aluminium EN AW-Al 99,5, average area of equiaxed crystal (PKR) and average area of columnar crystal (PKK) were calculated by computer program to processing and image analysis after macroscopic metallographic research. Findings: The results of investigations and their analysis show, that contribution of these both mechanism models of additional crystal nucleuses formation i.e. magnetic field influence and introduction of small amount of inoculant - less than in conventional modification process, should result in higher degree of fineness in pure metals structure. It is not possible, when we use one of these methods. We must use these two methods together. Research limitations/implications: I further research, authors of this paper are going to identify the "washers" to heterogeneous nucleation, which influences on increase of size reduction in structure. Practical implications: The work presents refinement of structure methods which are particularly important in continuous and semi - continuous casting where products are used for plastic forming. Originality/value: The value of this paper resides in coupling of two fineness of structure methods. The first method is internal factor - inoculation with (Ti+B) and the second method is external factor - influence of electromagnetic field crystallization process.

4

Inoculation of aluminium with titanium and boron addition

Szajnar J., Wróbel T.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 23, nr 1

51-54

EN

Purpose: The main aim of studies was to determine mechanism of inocualtion of pure alumnium EN AW-A199.5 structure with addition of titanium and boron, which are introduced to liquid metal in small ammount - less than obligatory standard PN-EN 573-3 (concerning about aluminium purity). Design/methodology/approach: To investigations it was used light microscopy, X-ray Phase Analysis and TEM. Surfaces of samples which were prepared for macrostructure analysis were etched with use of solution of: 50g Cu, 400ml HCl, 300ml HNO3 and 300ml H2O. Surfaces of samples which were prepared for microstructure analysis were etched with use of solution of: 0,5ml HF, 99,5ml H2O. Thin foils for TEM investigations were electropolished with use of 20 ml HClO4 and 80ml CH3OH. Findings: The results of investigations and their analysis show, that increase of size reduction in aluminium EN AW-A199,5 after inoculation with (Ti+B) result from "washers" of type Ti3Al and CuTi2 to heterogeneous nucleation formation. Research limitations/implications: I further research, authors of this paper are going to identifiy the "washers" to heterogeneous nucleation, in aluminium structure after inoculation with zirconium and vanadium addition. Practical implications: The work presents refinement of structure method which are particularly important in continuous and semi - continuous casting where products are used for plastic forming. Large columnar crystals zone result in forces extrusion rate reduction and during the ingot rolling delamination of external layers can occur. Thus, in some cases ingot skinning is needed, which rises the production costs. Originality/value: Contributes to research on size reduction in pure aluminium structure.

5

New approach to study tribological properties of polymer materials. A case of car windshield wipers

Bielinski D. M., Glab P., Slusarski L.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 15, nr 1-2

71--78

EN

Purpose: Existing approach to tribology of polymer materials does not take into account their composition and structure. This paper presents the original analysis of friction characteristics, enabling an insight from the material engineering point of view. Design/methodology/approach: Apart friction also dissipation energy spectra have been analyzed. For transformation of friction fluctuations from the force into the frequency domain the FFT methodology has been applied. Parameters for evaluation of friction and wear have been proposed. Results of bench tests have been verified by examinations of wiper blades under conditions simulating real exploitation, adapting a system of car window cleaning. Power consumption by a driving engine has been monitored. Findings: Various kinds of modifications, influencing composition and structure of polymer materials have been studied. Ageing and wear resistance have been found to be the most important from the point of view of working properties of blades. They influence the efficiency of water removal from a car window. Research limitations/implications: Different blade designs have to be checked working under various conditions. Practical implications: A correlation between tribological properties and structure of polymer materials has to be taken into account at the stage of their compounding and processing. The proposed method for testing car windshield wiper blades is more appropriate than standards used so far, enabling quantitative assessment of products. Originality/value: The paper helps to understand materials engineering aspects of tribology. It is of potential value for producers of polymer parts.

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Wpływ twardych warstw powierzchniowych typu TiN+(Ti, Al, Si)N+TiN na własności użytkowe cermetali narzędziowych i węglików spiekanych

Dobrzański L.A., Gołombek K.

Inżynieria Materiałowa

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2003

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R. XXIV, nr 6

449-452

PL

W pracy przedstawiono wyniki badań strukturalnych, własności mechanicznych oraz eksploatacyjnych przeciwzużyciowych powłok typu TiN+mono lub multi (Ti, Al, Si)N+TiN naniesionych w procesie PVD na podłoże z cermetali i węglików spiekanych. Przedstawiono badania strukturalne naniesionych powłok oraz podłoża w elektronowym mikroskopie skaningowym i na mikroskopie świetlnym. Oceny przyczepności pokryć naniesionych na węgliki spiekane i cermetale dokonano metodą zarysowania. Własności skrawne badanych materiałów określono na podstawie technologicznych prób ciągłego skrawania stali C45E. Jako kryterium oceny stopnia zużycia ostrza skrawającego przyjęto szerokość pasma zużycia na powierzchni przyłożenia narzędzia VBmax=0,2 mm, dla obróbki wykańczającej. Badania twardości podłoża i mikrotwardości naniesionych powłok przeprowadzono na ultramikrotwardościomierzu przy obciążeniu 70 mN. Dokonano również pomiarów chropowatości powierzchni przed naniesieniem powłok oraz po przeprowadzonym procesie PVD.

EN

The paper presents results of the structural examinations, tests of mechanical and working properties of thin anti-wear coatings of the TiN+mono or multi (Ti, Al, Si)N+TiN type, deposited in the PVD process onto the substrate from the tool cermets and sintered carbides. Structural examinations are presented of the applied coatings and their substrate made on the scanning electron microscope and on the light microscope. The lowest force Lc called the critical load was determined basing on the acoustic emission value (AE), at which loss of the coating adhesion to the substrate occurs. Cutting properties of the investigated materials were determined basing on the technological continuous cutting tests of the C45E steel. Width of the wear band on the tool flank VBmax=0,2 mm was assumed as the cutting edge wear criterion for finishing. Substrate hardness tests and microhardness tests of the deposited coatings were made on the ultramicrohardness tester at 70 mN load. Surface roughness tests were also made before depositing the coatings and after completing the PVD process.

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Konstrukcyjne i materiałowe uwarunkowania procesów pękania elementów rurociągu eksploatowanego w przemyśle chemicznym.

Cieśla M., Mutwil K., Wojas M.

Inżynieria Materiałowa

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1999

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R. XX, nr 3-4

186-192

PL

W pracy poddano analizie konstrukcyjne i materiałowe uwarunkowania procesów pękania rurociągu eksploatowanego w przemyśle chemicznym. Badania przeprowadzono dla wybranych elementów rurociągu, takich jak trójnik i złącze spawane. Wykonano numeryczne obliczenia stanu wytężenia materiału rurociągu w ujęciu globalnym i lokalnym. Przeprowadzono badania metaloznawcze najbardziej zdegradowanych obszarów rurociągu. Omówiono wpływ przepływającego przez rurociąg czynnika (para-metan) i obciążeń cieplno-mechanicznych na obserwowane w badaniach procesy powstawania i wzrostu pęknięć. Zaproponowano wytyczne, dotrzymanie których pozwoli na poprawę własności eksploatacyjnych analizowanego obiektu.

EN

Structural and material conditions of cracking processes of a pipeline working in the chemical industry were analysed in the paper. The tests were performed for selected elements of the pipeline such as T-connection and a welded joint. Numerical calculations of the effort state of the pipeline material were made in global and local aspect. Structural metallurgy tests were conducted on the most degraded areas of the pipeline. An influence of an agent (vapour-methane) flowing through the pipeline and thermal-mechanical loads on the crack formation and growth processes observed in the tests were discused. Guidelines were suggested and complying with will ensures improvement of working properties of the analysed object.