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1
Badania trybologiczne materiałów inżynierskich
100%
Pakieła W. , Bonek M. , Pakieła K.
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2018
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tom R. 23, nr 3
26--30
2
Content available remote Influence of manufacturing technology on tribological properties of A390.0 alloy
100%
Wieszała R. , Piątkowski J. , Roszak M. , Pakieła W.
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tom Vol. 77, nr 1
13--17
EN
Purpose: In this paper, results of tribological studies on AlSi17Cu5Mg alloy subjected to a modification (CuP10) and a significant overheating above Tliq are presented, referring them to the starting material. Design/methodology/approach: The influence of the applied technologies on the refinement of the primary crystals of Si was defined by determination of stereological parameters. In case of the overheated alloy, the primary crystals of silicon assume the forms of polygons with sharp edges after the overheating. In practice, it results in a decrease in tribological properties and an increase in the coefficient of friction in relation to the alloy modified with phosphorus. Findings: The result show that all investigated properties were changed. Significant differences between the analyzed specimens were proved in the friction coefficient and in the wear rate of the tested friction connections. Research limitations/implications: The application of modified by CuP10 aluminum alloy allows to reduce the friction coefficient between tested surface and counter-samples and also reduce the wear rate. This property’s causes that this material can be used in many applications where the aim is to reduce friction coefficient and wear rate. Practical implications: Reducing of friction coefficient and increase wear resistance causes that these materials can be used in many applications in the automotive industry such as blocks of engines, cylinders etc. Originality/value: Influence of aluminium modification on chosen tribological properties have been investigated.
3
Content available remote Laser surface alloying of sintered stainless steels with SiC powder
100%
Brytan Z. , Dobrzański L. A. , Pakieła W.
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tom Vol. 47, nr 1
42--56
EN
Purpose: The goal of this study is to investigate effects of laser surface alloying with SiC powder on microstructural changes and properties of vacuum sintered austenitic X2CrNiMo17-12-2, ferritic X6Cr13 and duplex X2CrNiMo22-8-2 stainless steels. Design/methodology/approach: Surface modification of sintered stainless steels was carried out by laser surface alloying with SiC powder using high power diode laser (HPDL). The influence of laser alloying conditions, the laser beam power (between 0.7 and 2.1 kW) at constant scanning rate on the width of alloyed surface layer and penetration depth were studied. The resulting microstructure in laser alloyed surface layer was examined using light and scanning electron microscopy. Phase composition was determined by the X-ray diffraction method. The microhardness results of modified surface layer were also studied. Findings: The alloyed surface layer has a fine dendritic microstructure with iron-chromium carbides precipitations. The surface layer was enriched in silicon and carbon that produced microstructural changes and resulting microhardness increase. Beside studied stainless steels the duplex one revealed highest hardening effect by laser alloying with SiC powder, where related microhardness was about 500-600 HV Practical implications: Laser surface alloying with SiC powder can be an efficient method of surface layer hardening of sintered stainless steels and produce significant improvement of surface layer properties in terms of hardness and wear resistance. Originality/value: Application of high power diode laser can guarantee uniform heating of treated surface, thus uniform thermal cycle across processed area and uniform penetration depth of alloyed surface layer.
4
Content available remote Fabrication methods and heat treatment conditions effect on structure and properties of the gradient tool materials
100%
Dobrzański L. , Kloc-Ptaszna A. , Pawlyta M. , Pakieła W.
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tom Vol. 56, nr 1
5-21
EN
Purpose: This work concerns manufacturing and research on a new group of the gradient tool materials, manufactured by the conventional powder metallurgy method, consisting in compacting a powder in a closed die and sintering it. Design/methodology/approach: The materials were obtained by mixing the powders of the HS6-5-2 high-speed steel, tungsten carbide (WC). The mixes were poured one after another into the die, yielding layers with the gradually changing volume ratio of carbides within the high-speed steel matrix. Structural research by using the scanning and transmission electron microscopes, x-ray microanalysis and density, hardness and porosity tests, were performed. Structure and hardness of selected materials after heat treatment were also investigated. The pin on plate test was used in order to examine the tribological properties of the analyzed materials. Findings: On the basis of the results of the research, it was found that it is possible to obtain gradient materials by the powder metallurgy methods, in order to ensure the required properties and structure of the designed material. It was shown that the new sintered graded materials are characterized by a multiphase structure, consisting of ferrite, primary carbides of the high speed steel, of the MC and M6C type, and dependently of the reinforcement phase, of the tungsten carbide WC which are introduced into the material, in the powder form. It has been proved by the pin on plate test that the addition of the tungsten carbide to the high-speed steel significantly improved the tribological properties. Practical implications: Developed material is tested for turning tools. Originality/value: The material presented in this paper has layers consisting of the carbide-steel with growing hardness on one side, and on the other side the high-speed steel, characterized by a high ductility.
5
Content available Preparatyka do celów mikroskopii świetlnej i skaningowej
100%
Kloc-Ptaszna A. , Pakieła W. , Snopiński P.
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2017
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tom R. 22, nr 6
24--28
6
Content available Influence of Chemical Composition on the Properties of Experimental Silicone-Based Soft Lining Composites
88%
Jabłońska-Stencel E. , Pakieła W. , Żmudzki J. , Kasperski J. , Chladek G.
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7
Content available Selected tribological parameters for silumin alloy used for engine piston
88%
Kozuba J. , Wieszała R. , Mendala J. , Roszak M. , Pakieła W.
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tom Vol. 107, nr 2
64--71
EN
Purpose: The conducted tests were aimed at determining whether the tested material meets the requirements for wear resistance in modern turbocharged combustion engines where there is an increased temperature and higher pressure. Design/methodology/approach: The tests were performed in a pin-on-disc system, according to the ASTM G 99 standard. Findings: The article presents the results of the coefficient of friction, the amount of wear, chemical analysis and surface profile of the tested material A390.0 in combination with EN GJL-350 cast iron. Research limitations/implications: The tested materials are used in the construction of pistons for internal combustion engines, therefore the test parameters were selected to take into account the operating conditions in a turbocharged engine with a power of up to 100 kW. Practical implications: After analysing the properties of the A390.0 alloy at elevated temperatures, it was found that without additional modifications, the alloy cannot be used in modern combustion engines, in particular with turbocharging. Originality/value: Presents the results of research concerning mechanical properties (HB, HV, Rm) and yield properties (R0.2, A5, Z) of the examined alloy.
8
Content available remote Stare dane, nowe wyniki
75%
Baryła R. , Ciećko A. , Popielarczyk D. , Oszczak S. , Biedrzycki K. , Pakieła W.
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tom nr 2
9--11
9
Content available Effects of Different Inorganic Fillers on Mechanical Properties and Degree of Conversion of Dental Resin Composites
75%
Stencel R. , Pakieła W. , Barszczewska-Rybarek I. , Żmudzki J. , Kasperski J. , Chladek G.
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10
Content available remote Effect of silica filler on properties of PMMA resin
75%
Chladek G. , Żmudzki J. , Basa K. , Pater A. , Krawczyk C. , Pakieła W.
Archives of Materials Science and Engineering
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2015
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tom Vol. 71, nr 2
63--72
EN
Purpose: Of this paper was to investigate the effect of silica nanofiller addition to PMMA-based denture material. The null hypothesis was that no difference exists between the mean flexural strength, hardness, sorption among materials without and with different content of silica filler. Design/methodology/approach: The nanosilica was introduced into “powder” component of commercially available PMMA resin for dentistry in concentrations 2, 5 and 10%. The SEM observations were made to confirm dispersion quality. To confirm presence of silica filler the X-ray microanalysis have been made. The influence of nanosilica addition on flexural strength, flexural modulus, hardness and sorption were investigated. Samples were stored at distilled water and ethanol solution. Statistical analysis were prepared with the one-way or the two-way analysis of variance ANOVA ( α =0.05), and Newman-Keuls significant difference post hoc test was used to determine the differences between mean values ( α =0.05). Findings: The result show that all investigated properties were changed after silica filler addition. Initially flexural strength decreased, but after accelerated again in ethanol incised. Flexural modulus and hardness increased. Sorption was decreased in both aging liquids. Research limitations/implications: Limitations resulting from the specificity of the conditions of laboratory tests and aging conditions so it does not allow to fully translate obtained results to expected results of clinical trials. Practical implications: The PMMA drawback is still insufficient mechanical properties, so it can be easily damaged during an accidents or when a patients applies high mastication force to the denture which show areas for further mechanical properties improvement. One of the ways of improving the mechanical properties of PMMA based materials may be nanoparticle addition, including commonly used nanosilica fillers. Originality/value: Influence of destructive plasticizing solutions on chosen properties of materials with different concentrations of silica fillers have been investigated.
11
Content available The Effect of Laser Surface Treatment on Structure and Mechanical Properties Aluminium Alloy ENAC-AlMg9
63%
Dobrzański L. A. , Pakieła W. , Tański T. , Labisz K. , Basa K. , Roszak M.
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nr 3
12
Content available Properties of the Aluminium Alloy EN AC-51100 after Laser Surface Treatment
50%
Król M. , Tański T. , Tomiczek B. , Pakieła W. , Janicki D.
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