Wyniki wyszukiwania - Biblioteka Nauki

1

Influence of nanoparticles additivies on mechanical properties of fabric reinforced composites

100%

Suchy T. , Balik K. , Sucharda Z. , Cerny M. , Sochor M.

Engineering of Biomaterials

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2007

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tom Vol. 10, no. 69-72

1-2

2

Microstructure of chitosan-based, ZnO-doped antibacterial composite

80%

Ciołek L. , Biernat M. , Jaegermann Z. , Zaczyńska E. , Czarny A. , Jastrzębska A. , Olszyna A.

Engineering of Biomaterials

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2017

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tom Vol. 20, no. 143 spec. iss.

18

3

Acrylic composite materials modified with bee pollen for biomedical application

80%

Florkiewicz W. , Sobczak-Kupiec A. , Tyliszczak B.

Engineering of Biomaterials

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2017

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tom Vol. 20, no. 143 spec. iss.

27

4

Magnetic properties of magnetostrictive Tb0.3Dy0.7Fe1.9 / polyurethane composite materials

80%

Dobrzański L. , Tomiczek A. , Nabiałek A. , Stokłosa Z.

Archives of Materials Science and Engineering

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2011

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tom Vol. 51, nr 2

97-102

EN

Purpose: The aim of this work was to obtain polyurethane matrix composite materials reinforced with Tb0.3Dy0.7Fe1.9 particles and to observe changes of magnetic properties and magnetostriction of samples with different particle size distributions of Tb0.3Dy0.7Fe1.9 powder and varying volume concentration. Design/methodology/approach: The studies was performed on composite materials with the polyurethane matrix reinforced with Tb0.3Dy0.7Fe1.9 powders. The morphology of powder was examined by scanning electron microscopy (SEM) and analysis of the grain distribution of Tb0.3Dy0.7Fe1.9 powder was made using the Mastersizer 2000 analyser. The changes of magnetostriction and magnetic properties, including hystersis loops and effective permeability with changing applied field are tested. Findings: Analysis establishes a direct connection between magnetic properties and structural characteristics of the Tb0.3Dy0.7Fe1.9 powder size, which was used as reinforcement phase. The increase of particle size distribution of Tb0.3Dy0.7Fe1.9 powder in composite materials amplify the magnetostrictive responses, moreover the change of magnetic properties as a function of volume fraction of Tb0.3Dy0.7Fe1.9 powder were confirmed. Research limitations/implications: Contributes to research on structure and properties of magnetostrictive composite materials with the polymer matrix reinforced with Tb0.3Dy0.7Fe1.9 powders. Practical implications: The polymer matrix in investigated composite materials causes growth of resistivity, limiting this way losses for eddy currents at the high operating frequency of the transducers. In addition the values of permeability of composite materials is nearly constant in investigated frequency range. Originality/value: The obtained results show the possibility of manufacturing the magnetostrictive composite materials based on the Tb0.3Dy0.7Fe1.9 particles, with desired properties in cost effective way in comparison to conventional giant magnetostrictive materials (GMM).

5

Effect of a low pH on HAp/glucan composite

80%

Borkowski L. , Kiernicka M. , Belcarz A. , Pałka K. , Hajnos M. , Ginalska G.

Engineering of Biomaterials

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2016

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tom Vol. 19, no. 138 spec. iss.

22

6

Effect of retardants on the heat release during setting of bone cement-type composites

80%

Pijocha D. , Łój G. , Nocuń-Wczelik W. , Ślósarczyk A.

Journal of Achievements in Materials and Manufacturing Engineering

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2011

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tom Vol. 49, nr 2

204--209

EN

Purpose: The aim of this work was to investigate the influence of retardants on the heat release during setting of the new hydroxyapatite (HA) - magnesium phosphate cement (MPC) - calcium sulphate hemihydrate (CSH) composites. Design/methodology/approach: We used the calorimetric method to measure the temperature effect of setting reaction in these new composites. Microstructure observations by means of scanning electron microscopy was also performed. Findings: The decrease in maximum temperature reached during hardening process with use of different retardants was confirmed. Research limitations/implications: Biological evaluation and in vitro physico-chemical tests of the novel composites need to be done. Practical implications: The highly exothermic setting reaction of cement composites based on MPC can be lowered to avoid harmful necrosis of the tissues surrounding the implant material. Originality/value: Detailed studies on the heat release during setting of HA - MPC - CSH composites were performed for a first time, giving an opportunity to choose the best composition for further studies.

7

Influence of thermal boundary condition on casting process of metal matrix composite

80%

Zagórski R. , Śleziona J.

Archives of Materials Science and Engineering

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2010

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tom Vol. 42, nr 1

53-61

EN

Purpose: of this paper is to present a computer simulation as a tool for modelling the gravity casting process of metal matrix composite (MMCs) in the sand mould and predicting the arrangement of heterophase reinforcement particles in the composite and impact of the parameter which characterizes the thermal boundary condition on the course of solidification process (speed, direction) and thus, on the arrangement of reinforcement particles. Design/methodology/approach: Computer simulations have been carried out following the methods and procedures included in the program Fluent. The calculation are based on two-dimensional model in which the Volume of Fluid (VOF), enthalpy method and the Discrete Phase Model (DPM) have been applied to describe two-phase system, solidification and behaviour of reinforcement particles, respectively. The calculations also include the method which allows to model the contact resistance at the interface between mould wall and liquid alloy. Findings: Obtained results show that the cast solidification as well as final arrangement of heterophase reinforcement particles depend on the assumed thermal boundary conditions. The appearance of the contact resistance lengthens the solidification process and extends the effect of aggregation, sedimentation and particle engulfment or pushing ahead of solidification front. Research limitations/implications: The created model and procedures can be treated as a basis for more advanced researches. Practical implications: Presented simulations allows to study phenomena occurring during the casting process and predict the behaviour of the reinforcement particles (distribution of reinforcement) for the different thermal boundary conditions. Originality/value: The applied simulation methods allows to study the course of the casting process of metal matrix composite and arrangement of the reinforcement particles.

8

Próby wytwarzania nasyconych odlewów kompozytowych z wykorzystaniem maszyny ciśnieniowej

80%

Jackowski J.

Kompozyty

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2003

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tom R. 3, nr 6

106-109

PL

Nasycane odlewy kompozytowe wytwarzane są najczęściej z użyciem urządzeń autoklawowych lub przez prasowanie w stanie ciekłym (squeeze casting). Pierwszy sposób umożliwia zachowanie korzystniejszych warunków nasycania (i ich kontrolę), drugi znacznie większą wydajność. Jedną z przyczyn porowatości nasycanych odlewów kompozytowych są okluzje gazowe. Ich obecność w nasycanym odlewie jest nieunikniona, szczególnie w przypadkach nasycania prasowaniem. Ciśnienie zewnętrzne wywierane na metal osnowy nasycającej zbrojenie winno być wyższe od sumy ciśnień koniecznych do: pokonania ciśnień kapilarnych w nasycanym zbrojeniu, pokonania oporów przepływu osnowy przez kapilarno-porowate zbrojenie oraz kompresji okluzji (rys. 1). Podjęto próby wytwarzania nasycanych odlewów kompozytowych w formie ciśnieniowej (rys. 2) z wlewem doprowadzającym o dużej powierzchni przekroju, pozwalającym na uzyskiwanie niewielkich prędkości przepływu nasycającego metalu osnowy. Forma ciśnieniowa przystosowana była do współpracy z maszyną ciśnieniową IDRA 320. Odlewy próbne, o kształcie prostopadłościennych płytek o wymiarach 70x60x20 mm, uzyskiwano przez nasycanie glinokrzemianowego zbrojenia SIBRAL technicznym stopem AlSi11. Uzyskane odlewy próbne (rys. 3) cięto na fragmenty (rys. 4), a porowatość każdego z nich określano na podstawie pomiarów jego gęstości (metodą podwójnego ważenia na elektronicznej wadze analitycznej WPA 120K). Przykłady stwierdzonych rozkładów porowatości odlewanego materiału kompozytowego uzyskanego w trakcie prób nasycania zbrojeń przy różnych wartościach ciśnienia zewnętrznego przedstawiono na rysunkach 5 i 6. Wstępne próby dowiodły możliwości otrzymywania nasycanych odlewów kompozytowych o porowatości niższej od 1% w warunkach standardowej odlewni ciśnieniowej przy stosowaniu niewielkich wartości posuwów tłoka maszyny ciśnieniowej oraz dostatecznie sztywnych zbrojeń kompozytowych.

EN

Saturated composite castings are usually produced with the use of autoclave equipment or by pressing of the charge in liquid state (squeeze casting). The first method enables maintaining better saturation conditions (and their monitoring), while the other considerably improves efficiency of the process. One of the reasons of porosity of saturated composite castings results from gas occlusions. They are unavoidable in the saturated castings, particularly in the case of pressing saturation. External pressure exerted on the matrix metal saturating the reinforcement should exceed the sum of pressures necessary for overcoming capillary pressures in the reinforcement under saturation, resistance of matrix flux through the capillary-porous reinforcement, and occlusion compression (Fig. 1). The attempts were made at producing saturated composite castings in a pressure casting die (Fig. 2) the ingate of large cross-section area, enabling operation with small velocity of saturating matrix metal flux. The pressure casting die was adapted for co-operation with the IDRA 320 pressure casting machine. Trial castings, of the shape of rectangular plates 70x60x20 mm, were obtained by saturating an aluminosilicate SIBRAL reinforcement with a technical AlSi11 alloy. The trial castings (Fig. 3) where then cut into parts (Fig. 4). Their porosities were determined based on measured densities (with a method of double weighing at an electronic analytical balance WPA 120K). Examples of porosity distribution of the casted composite materials obtained by reinforcement saturating for different external pressure values are shown in Figures 5 and 6. Preliminary trials proved the possibility of obtaining the saturated composite castings of porosity below 1 per cent, under conditions of a standard pressure-casting foundry, provided that small piston advance value and sufficiently rigid composite reinforcement are used.

9

Specific Bending and Compressive Strenght of Poly(Vinyl Alcohol)-CNT Composites

80%

Zygoń P. , Nitkiewicz Z.

Archives of Metallurgy and Materials

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2016

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tom Vol. 61, iss. 2B

993--996

EN

Carbon nanotubes are one of the strongest materials of unique mechanical, optical, electrical and electronic properties. Because of that they are mainly used as semiconductor materials constituting the reinforcing phase in composite materials. The paper presents properties of polymer composites reinforced with carbon nanotubes (CNT) containing various mixtures of dispersion. Produced composites featured various content carbon nanotubes: 20%, 30%, 40% i 50%. Macroscopic observations were carried out on ready to check composites, if pores exist in the structure and whether the reinforcement has been distributed in the entire volume. Bending and compressive strengths tests were performed and densities of individual composites were measured to determine the specific strength. Composite materials strengthened with carbon nanotubes feature a very low density and a very good mechanical strength, which makes them a good structural material.

10

Simulation of wave propagation in damped composite structures with piezoelectric coupling

80%

Schulte R. T. , Fritzen C.-P.

Journal of Theoretical and Applied Mechanics

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2011

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tom Vol. 49 nr 3

879-903

EN

This paper presents an efficient and accurate simulation approach to shorten time and cost of the necessary pre-tests in the design process of structural health monitoring (SHM) systems. The simulation is performed using the time domain spectral element method, which leads to an optimally concentrated mass matrix and results in a crucial reduction of complexity of the time integration algorithm. The theoretical background of the method and a spectral element for flat shells are presented. New approaches to incorporate the anisotropic material damping and an efficient coupling of piezoelectric elements within the spectral element framework are developed. Some numerical calculations are performed showing both the accuracy of this methodology, by comparing to experimental values, and the applicability to more complex structures like stiffened curved panels.

PL

W pracy przedstawiono efektywną i dokładną procedurę symulacji układów z systemem monitorowania stanu (SHM) stosowaną na wstępnym etapie projektowania takich układów i pozwalającą na redukcję czasu i kosztów niezbędnych analiz wstęp- nych. Procedurę oparto na metodzie elementów spektralnych w dziedzinie czasu, co umożliwiło uzyskanie optymalnie określonych macierzy bezwładności i przez to zdecy- dowane skrócenie czasu całkowania. Przybliżono podstawy teoretyczne metody i opisano elementy spektralne dla płaskich powłok. Przedyskutowano nową metodologię badań symulacyjnych pozwalających na wprowadzenie tłumienia anizotropowego oraz efektu sprzężenia piezoelektrycznego w ujęciu elementów spektralnych. Na kilku przykładach zaprezentowano dokładność obliczeń numerycznych poprzez porównanie ich z wynikami eksperymentu oraz wykazano ich przydatność do analizy bardziej złożonych układów, jak np. zakrzywionych paneli z lokalnymi usztywnieniami.

11

On continuum modelling of dynamic problems in composite solids with periodic microstructure

80%

Rychlewska J. , Woźniak C.

Journal of Theoretical and Applied Mechanics

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2003

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tom Vol. 41 nr 4

735-753

EN

In this contribution we propose an approach to the macroscopic modelling of periodic composites which is based on the periodic simplicial subdivision of the unit cell. This approach makes it possible to derive a hierarchy of continuum models which describe dynamic behaviour of periodic composites on different levels of accuracy. The obtained results are compared and applied to the analysis of a certain wave propagation problem.

PL

W pracy zaproponowano nowe podejście do modelowania zagadnień dynamiki w liniowo-sprężystych mikroperiodycznych ośrodkach ciągłych, które za punkt wyjścia przyjmuje periodyczny podział symplicjalny elementu reprezentatywnego struktury. Podejście to umożliwia wyprowadzenie pewnej hierarchii modeli ciągłych, które opisują zagadnienia dynamiki z różną dokładnością. Otrzymane wyniki zastosowano do analizy propagacji fali w nieograniczonym ośrodku o budowie mikroperiodycznej.

12

Lightness factors and exertion factors related to its own mass of fiber reinforced plastics (FRP) applied in composite aeronautical structures (Part 1)

80%

Rodzewicz M. , Lewitowicz J.

Journal of KONBiN

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2018

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tom No. 47

5--22

EN

The paper concerns an application of lightness factors in comparative analysis of strength properties of basic materials being applied in aeronautical structures – in a historical perspective. The use of lightness factors enables effective estimation how lighter will be the structural elements (of the same strength or stiffness ) made from different kind of materials : traditional as well as advanced composites. It is quite easy to find the solution to the inverse problem, i.e. to estimate how differ will be stiffness or strength for the same mass of the structural elements. Very particular application of the lightness factors are noted in engineers calculations of composite gliders wing spars, where they appears as the materials constants and as structure loading factors as well. The paper presents some examples of application of the lightness factors in strength analysis of the composite shells applied in the shear webs of the wing spars, and refers to the design recommendations issued by German aviation authority (LBA).

PL

W pracy opisano wykorzystanie wskaźników lekkości w analizie porównawczej właściwości wytrzymałościowych podstawowych materiałów konstrukcyjnych stosowanych w budowie płatowców w ujęciu historycznym. Zastosowanie wskaźników lekkości umożliwia szybkie oszacowanie o ile lżejsze będą przy tej samej wytrzymałości lub sztywności elementy strukturalne wykonane z różnego rodzaju materiałów – zarówno tradycyjnych, jak też różnych kompozytów polimerowych. Łatwo jest również znaleźć rozwiązanie dla zagadnienia odwrotnego, tzn. oszacować ile będą różnić się sztywności lub wytrzymałości przy tej samej masie elementów strukturalnych. Wskaźniki lekkości znalazły szczególne zastosowanie w inżynierskich obliczeniach kompozytowych dźwigarów skrzydeł szybowców, występując w nich zarówno jako stałe materiałowe, oraz jako wskaźniki wytężenia struktury. W pracy podano przykłady zastosowania tych wskaźników do analizy powłok kompozytowych stosowanych w ściankach dźwigarów skrzydeł oraz odniesiono się do zaleceń projektowych stosowanych przez niemiecki nadzór lotniczy (LBA).

13

Otrzymywanie kompozytów W/WxC metodą SPS

80%

Macherzyńska B. , Matsuura K.

Materiały Ceramiczne

|

2007

|

tom R. 59, nr 3

118-120

PL

Artykuł opisuje zastosowanie metody SPS (Spark Plasma Sintering) do otrzymywania spieków z proszków roztworów stałych w układzie W-C otrzymanych metodą spalania. W celu zbadania podstaw wytwarzania materiałów gradientowych (FGM) w tym układzie, przygotowano próbki o zawartości węgla zmieniającej się od 10 do 60% at. Strukturę i właściwości otrzymanych materiałów badano za pomocą mikroskopii optycznej i skaningowej, dyfrakcji rentgenowskiej oraz pomiarów twardości Vickersa. Znaleziono korelacje pomiędzy udziałem węgla w wyjściowej mieszaninie substratów, a składem fazowym, twardością i mikrostrukturą otrzymanych tworzyw. Ponadto, wytworzono materiały gradientowe o zawartości węgla 10, 30 i 50 % at. Właściwości mechaniczne materiałów gradientowych zmieniały się z udziałem węgla. Wytworzono materiał, w którym ziarna węglika wolframu o zmiennym składzie były wiązane wolframem metalicznym.

EN

For combustion-synthesizing of W-C hard alloys from the elemental powders, the spark plasma sintering (SPS) method was used. To establish a fundamental base of processing of functionally graded materials (FGM), samples with different atomic fraction of carbon, from 10 at% up to 60 at%, were produced. The structure and properties were systematically characterized by optical microscopy, scanning electron microscopy, X-ray diffraction analysis, and Vickers hardness measurement. Interestingly, a correlation between atomic fraction of carbon in the elemental powder mixture and hardness, microstructure and constituting phases after the synthesis has been found. Successively, the FGM samples with a graded carbon fraction of 10, 30 and 50 at% were produced. The mechanical properties of these FGM samples changed with the carbon fraction. Finally a graded material tungsten carbide was bonded with pure tungsten metal.

14

Electrical Properties of BaCeO₃-Based Electrolytes for use in Dual Protonic Ceramic-Solid Oxide Fuel Cells

80%

Gawel R. , Przybylski K.

Acta Physica Polonica A

|

2017

|

tom 131

|

nr 5

1361-1366

EN

Bulk samples consisting of BaCe_{0.85}Y_{0.15}O_{3-δ} (BCY15) and Ce_{0.85}Y_{0.15}O_{2-δ} (YDC15) compounds, mixed together in different ratios, were studied as potential electrolytes in dual protonic ceramic-solid oxide fuel cells and compared with non-composite BCY15 and YDC15. The microstructures of the sintered materials indicate that BCY15 exhibits the largest grains, whereas composites have greater visible porosity than the non-composite samples. From X-ray diffraction studies it follows that BCY15 and YDC15 consist mainly of one phase, whereas the composites are two-phase materials. Electrochemical impedance spectroscopy studies at different temperatures show that the composite materials are capable of conduction the order of 10¯³ S/cm at temperatures above 500°C in a hydrogen-containing atmosphere. Furthermore, activation energy values of the conductivity determined for the composites in air atmosphere are between those obtained for BCY15 (E_{a}=0.590±0.017 eV) and YDC15 (E_{a}=1.132±0.008 eV). From this it follows that both phases of the composites influence the electrical conductivity of the materials. In conclusion, BCY15 and the BCY15-YDC15 composites show promise for future use as electrolytes in dual protonic ceramic-solid oxide fuel cells.

15

Degradation of composites based on raw materials for orthopedic equipment

80%

Szaraniec B. , Morawska-Chochół A. , Stodolak-Zych E.

Engineering of Biomaterials

|

2012

|

tom Vol. 15, no. 116-117 spec. iss.

147

EN

Eco-composites based on natural raw materials such as polylactide and plant fibres (e.g. flax, hemp, jute) show many important features which enable them to be used as potential materials for biomedical engineering. Availability of the raw materials and low costs of production, capability to enhance mechanical parameters and also controlled time of degradation in the environment allow considering them as materials for rehabilitation equipment, orthopedic supplies or materials for medical packages. Such materials due to the presence of the natural fibres provide higher comfort during their utilization and then they undergo safe biodegradation which is non-harmful for the environment [1,2]. The work presents attempts on fabrication of composites based on polylactide (PLA, Ingeo 3051D, Nature works, USA) reinforced with short flax and jute fibres. The fibres were mechanically comminuted to the length of 1-2 mm. Preparation of PLA/fibres mixture took part in two stages. The first one consisted in drying of the polymer granulate and the fibrous filler at 60 degrees of Celsius for 2 h. The second stage the granulate/fibres mixture was homogenized using vertical screw injection moulding machine (Multiplas). The obtained mixture was mechanically comminuted with a laboratory grinder (Testchem). Volume fraction of the fibres was nit higher then 5 %. The granulates were used to prepare PLA/natural fibres composites in the form of paddle-shaped samples (according to PN-EN ISO 527) by the injection method. The injection took place at 165 degrees of Celsius and pressure of 80 kg/cm2. The samples were subjected to hydrolytic degradation tests (incubation in distilled water at 37 degrees of Celsius, 15 weeks) and biological degradation (composting in an eco-composter, TERMO-410 with the addition of Radvit activator which contains composting bacteria and selected fungi cultures which support biodegradation and accelerate degradation of organic wastes, 15 weeks). The effect of the degradation environment on the composite material was determined on the basis of changes of its mechanical properties (tensile strength, Young's modulus) using an universal testing machine (Zwick 1453). The degradation process was monitored by FT-IR spectroscopy of the composite samples (transmission method, BioRAD 60FT). Changes related to the polymer chain degradation were assessed on the basis of viscosimetric measurements (Hoppler method). The carried out investigations proved, that during both the composting and the incubation in water a gradual degradation of the material takes place. Its visual effect was decrease of the tensile strength of the composites for about 70% for PLA/5% jute and for c.a. 10% for PLA/5% hemp and their Young's modulus for about 25 % for PLA/5% jute and for c.a. 10% for PLA/5% hemp. The changes were caused by decrease of molecular weight (Mn) of the polymer matrix from 100 to 28 kDa for PLA/5% hemp, and from 136 to 48 kDa for PLA/5% jute. The change of the polymer structure was faster in the case of degradation in water environment. This effect was related to facilitated migration of medium (water) inside the material and possibility of washing out and transport of products of the polymer chain disintegration. Additionally, the present fibrous phase which is characterized by high water absorbability may became a reservoir of both the medium and the degradation products. Biodegradation in the compost heap was slower and it was an example of synergic effect of hydrolytic degradation and biodegradation caused by the microorganisms. This process could be observed on the FT-IR spectra recorded during degradation in the compost heap, where longer composting time led to increasing disproportion between bands indicating increasing fraction of hydroxyl, carboxyl and carbonyl groups in relation to groups characteristic for PLA chain. In the case of biodegradation the process progress is related to such variable factors as: amount and type of the bacteria and fungi cultures, humidity and temperature. In conclusion, it may be stated that the proposed PLA/natural fibres composite materials are an alternative solution for many fields of biomedical engineering especially for rehabilitation and orthopedic provision.

16

The use of waste materials as fillers in polymer composites-synthesis and thermal properties

80%

Gargol M. , Podkościelna B.

Physicochemical Problems of Mineral Processing

|

2019

|

tom Vol. 55, iss. 6

1549--1556

EN

This paper presents the synthesis and characterization of new polymeric materials in form of composites. As a fillers, waste materials of inorganic origin (ash and silica gel), were used. In the synthesis of composites, two derivatives of bisphenol A (glycerolate diacrylate, and epoxy resin, Epidian® 5), were applied. The compositions were prepared with an increasing amount of fillers 0-40% w/w in both tested systems. Composites were analyzed using the thermogravimetric analysis (TG/DTG), which showed the influence of different fillers on their thermal properties. Moreover, the proper course of the polymerization reaction was confirmed by spectroscopic analysis (ATR/FT-IR). It has been shown that new resistant materials can be obtained, using cheap and waste materials, by simple synthesis which does not require monitoring of the reaction course or expensive polymerization initiators.

17

Corrosion resistance of composite materials Fe73.5Cu1Nb3Si13.5B9 - PE type in acid environment

80%

Ziębowicz B. , Dobrzański L. , Drak M. , Wydrzyńska A.

Archives of Materials Science and Engineering

|

2008

|

tom Vol. 30, nr 2

89-92

EN

Purpose: The purpose of the paper is to present corrosion resistance of composite materials Fe73.5Cu1Nb3Si13.5B9 – PEHD type in acid environment. Design/methodology/approach: Composite materials Fe73.5Cu1Nb3Si13.5B9 – PEHD type were manufactured by one-sided uniaxal pressing. Composite materials were placed in a corrosive environment and two tests were carried out as specified below: test at the temperature of 25oC, solution of 0.1 M chloride acid HCl, time of 348h, test at the temperature of 25oC, solution of 0.1 M sulfuric (VI) acid H2SO4, time of 348h. Findings: The main purpose of obtaining this kind of composite materials is broadening possibilities of nanocrystalline magnetic materials application that influence on the miniaturization, simplification and lowering the costs of devices. Practical implications: The manufacturing of composite materials Fe73.5Cu1Nb3Si13.5B9 – PEHD type greatly expand the applicable possibilities of nanocrystalline powders of magnetically soft materials however further examination to obtain improved properties of magnetic composite materials and investigations of constructions of new machines and devices with these materials elements are still needed. Originality/value: Results allow to complete data concerning composite materials nanocrystalline powder – polymer type which are an attractive alternative for traditional materials with specific magnetic properties.

18

Multiphase microwave dielectricss

80%

Belous A. G. , Ovchar O. V.

Materials Science Poland

|

2011

|

tom Vol. 29, No. 1

47--55

EN

Several types of multiphase ceramic materials with excellent microwave (MW) dielectric properties have been considered. Studied materials were based on complex niobates and titanates with various crystal structures in which very high values of the MW quality factors (Q) can be attained. Slight compositional changes in the complex oxide systems have been shown to induce rather combined effect on the cation arrangement of separate crystal phases as well as on the microstructure and phase composition of multiphase ceramic materials. As a consequence, the ways to tailor MW dielectric parameters of the ceramics through a proper adjustment of both structure and distribution of enclosed phases have been presented and discussed. The examples of the multiphase MW dielectrics with enhanced properties have also been presented.

19

The influence of incubation media on surface properties of bioglass-polymer composites

80%

Flis A. , Zagrajczuk B. , Dziadek M. , Cholewa-Kowalska K. , Laczka M.

Engineering of Biomaterials

|

2018

|

tom Vol. 21, no. 148

99

20

Numerical analysis of the critical state of thin-walled structure with Z-profile cross section

80%

Różyło P. , Łukasik D.

Advances in Science and Technology. Research Journal

|

2017

|

tom Vol. 11, no 1

194--200

EN

The object of the study was a thin-walled profile with Z-shaped cross section made of the carbon-epoxy composite. The material model was prepared based on the implemented orthotropic properties. The purpose of the study was to determine the value of the critical load at which buckling occurs, the form of buckling and operating characteristics in critical condition. In order to achieve this numerical analysis were carried out. Additionally, the effects of the modification in arrangement of layers of the laminate to the stability and strength of thin-walled composite structures was presented. Numerical studies were carried out using commercial simulation software - ABAQUS®. Within the FEM research, both forms of buckling and the associated critical load, dependent on the configuration the layers of the composite were achieved. The analysis of the obtained results allowed the evaluation of the structure’s work in relation to the level of energy consumption or rigidity estimation. In the paper only numerical simulations of the critical state were conducted.