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1
Content available Wybrane zastosowania kompozytów w wojsku
PL
W artykule przedstawiono problematykę dotyczącą zastosowania nowych rozwiązań konstrukcyjnych z wykorzystaniem materiałów kompozytowych, na szeroko rozumiane potrzeby wojska. Pokrótce przedstawiono charakterystykę kompozytów i ich właściwości, wyszczególniając ich liczne zalety, a także niedostatki. Omówiono nowe konstrukcje podzespołów samolotów, śmigłowców oraz zasygnalizowano wzrost udziału kompozytów polimerowych w lotnictwie wojskowym i cywilnym. Przedstawiono zastosowanie kompozytów do ochrony żołnierza: elastyczną kamizelkę kompozytową i hełm, do ochrony przed promieniowaniem mikrofalowym, jak również egzoszkielet żołnierza ułatwiający operacje na polu działań. Podkreślono możliwości szerokiego zastosowania materiałów kompozytowych w różnych gałęziach przemysłu.
EN
The article presents the issue of applying new design solutions from composite materials for military needs. The article also includes composites’ characteristics and properties, underlining their benefits and deficiencies. New aircraft and helicopter subassembly designs were demonstrated, and an increased use of polymer composites in civil and military aviation was mentioned. In addition, the application of composites used for the soldier’s protection in the form of elastic composite west, helmet against microwave radiation was depicted, as well as the soldier’s exoskeleton to facilitate operations on the field. Composites are future-oriented materials applied in civil and military areas due to their properties.
PL
W artykule przedstawiono wyniki badań nad możliwościami wytwarzania i zastosowania kompozytu żelazo-zeolit otrzymanego za pomocą technologii metalurgii proszków. Dokonano także oceny jakości połączenia zeolitu z osnową i wpływu cząstek zeolitu na własności spieku. Przed procesem wytwarzania spieków wykonano badania morfologii i składu chemicznego zeolitu, który pozyskano ze skały zwanej tufem zeolitowym, wydobywanej w kamieniołomie w Kucinie (VSK PRO-ZEO s.r.o, Slowacja). Skałę do badań dostarczono w postaci zmielonego proszku o frakcji 0,0–0,2 mm. Następnie wykonano powierzchniową analizę SEM EDS i rentgenowską analizę fazową XRD. Przed procesem spiekania zastosowano jednostronne prasowanie na prasie hydraulicznej przy ciśnieniu prasowania 400 MPa. Proces spiekania przeprowadzono w laboratoryjnym piecu rurowym w temperaturze 950°C w atmosferze zdysocjowanego amoniaku. Czas spiekania wynosił 60 min. Wytworzone spieki poddano następującym badaniom: pomiarowi gęstości, twardości, porowatości. Przeprowadzono również obserwacje mikrostruktury i analizę składu chemicznego EDS na zgładach metalograficznych wykonanych z badanych spieków z użyciem skaningowego mikroskopu elektronowego. Zeolit wprowadzono do żelaznej osnowy w ilości 5, 10, 15% wag. Wprowadzenie do osnowy cząstek zeolitu jako fazy umacniającej, spowodowało podwyższenie porowatości i twardości spieków oraz obniżenie gęstości.
EN
The paper presents results of research on manufacturing technology and application of iron - zeolite composite obtained by powder metallurgy technology. The quality of the zeolite bonding with the matrix and the influence of zeolite particles on the sinter properties were evaluated. Before the sintering process, morphology and chemical composition of the zeolite was investigated, which was obtained from a rock called zeolite tuff, extracted from the quarry in Kucin (VSK PRO-ZEO s.r.o, Slovakia). The test rock was supplied as a powdered fraction of 0.0–0.2 mm. Surface analysis of SEM EDS and XRD XRD was performed. Prior to the sintering process, one-sided pressing on a hydraulic press was applied at a press pressure of 400 MPa. The sintering process was carried out in a laboratory tubular furnace at 950°C under dissociated ammonia. The sintering time was 60 minutes. The sintered materials were subjected to the following tests: density, hardness, porosity. Compression test the microstructure and analysis of the EDS chemical composition on metallographic specimens made from the investigated sinterings using scanning electron microscope were also carried out. Zeolite was added to the iron matrix at 5, 10, 15% by weight.Introducing the zeolite particles into the reinforcing phase has increased the porosity and hardness of the sinter, while decreasing the density.
EN
The present paper presents comparative results of the forecasting of a cutting tool wear with the application of different methods of diagnostic deduction based on the measurement of cutting force components. The research was carried out during the milling of the Duralcan F3S.10S aluminum-ceramic composite. Prediction of the tool wear was based on one variable, two variables regression, Multilayer Perceptron (MLP) and Radial Basis Function (RBF) neural networks. Forecasting the condition of the cutting tool on the basis of cutting forces has yielded very satisfactory results.
EN
In this paper, the problem of tool wear prediction during milling of hard-to-cut metal matrix composite Duralcan™ was presented. The conducted research involved the measurements of acceleration of vibrations during milling with constant cutting conditions, and evaluation of the flank wear. Subsequently, the analysis of vibrations in time and frequency domain, as well as the correlation of the obtained measures with the tool wear values were conducted. The validation of tool wear diagnosis in relation to selected diagnostic measures was carried out with the use of one variable and two variables regression models, as well as with the application of artificial neural networks (ANN). The comparative analysis of the obtained results enabled the selection of the most effective tool wear prediction method.
EN
Light weight, low density with high mechanical properties and corrosion resistance, aluminum is the most important material and is commonly used for high performance applications such as aerospace, military and especially automotive industries. The researchers who participate in these industries are working hard to further decrease the weight of end products according to legal boundaries of greenhouse gases. A lot of research was undertaken to produce thin sectioned aluminum parts with improved mechanical properties. Several alloying element addition were investigated. Yet, nowadays aluminum has not met these expectations. Thus, composite materials, particularly metal matrix composites, have taken aluminum’s place due to the enhancement of mechanical properties of aluminum alloys by reinforcements. This paper deals with the overview of the reinforcements such as SiC, Al2O3 and graphene. Graphene has recently attracted many researcher due to its superior elastic modulus, high fatigue strength and low density. It is foreseen and predicted that graphene will replace and outperform carbon nanotubes (CNT) in near future.
EN
Purpose: In the present study, the effects of B4C reinforcement volume fraction (% 5-15-20) on the abrasive wear properties of AA2024 matrix composites produced with hot pressing methods were investigated. Design/methodology/approach: As-received samples were also used for comparison. AA 2024 powder was mixed with B4C-SiC-Al2O3 particles by a three dimensional mechanic mixer for 30 minutes. Mixed powder was pressed under 60 MPa at room temperature in the steel mold by unidirectional. Steel mold kept in the furnace at 550ºC after the pre-pressing for 30 minutes. Samples were pressed in heated mold under 100 Pa. The wear tests were carried out using a pin-on-disk wear tester by sliding at sliding speeds of 1.2 m/s against silicon carbide paper. Normal loads of 10, 20 and 30 N at constant sliding speed at room temperature. Findings: The experimental result showed that B4C volume fraction significantly influence the wear behavior of AA2024 matrix composites produced with hot pressing methods. Originality/value: It was also found that the wear resistance of AA2024 matrix composites produced with hot pressing methods increases with increasing B4C volume fraction. The highest weight loss was obtained in the unreinforced matrix material.
EN
The presented work describes the results of examination of the mechanical properties of castings made either of AlSi9Mg alloy matrix composite reinforced with short carbon fibre or of the pure AlSi9Mg alloy. The tensile strength, the yield strength, Young’s modulus, and the unit elongation were examined both for initial castings and for castings made of the remelted composite or AlSi9Mg alloy. After preparing metallographic specimens, the structure of the remelted materials was assessed. A few non-metallic inclusions were observed in the structure of the remelted composite, not occurring in the initial castings. Mechanical testing revealed that all the examined properties of the initial composite material exceed those of the non-reinforced matrix. A decrease in mechanical properties was stated both for the metal matrix and for the composite after the remelting process, but this decrease was so slight that it either does not preclude them from further use or does not restrict the range of their application.
PL
Energia wybuchu może zostać wykorzystana do realizacji wielu procesów technologicznych, m.in. wytwarzania złączy zgrzewanych, prasowania proszków, tłoczenia, odprężania i utwardzania metali. Bardzo interesującym zastosowaniem technologii zgrzewania wybuchowego jest wytwarzanie kompozytów metalowych. W artykule scharakteryzowano kompozyty metalowe i zgrzewanie wybuchowe jako jedną z metod ich otrzymywania. Przedstawiono autorską technologię uzyskiwania kompozytów metalowych z osnową aluminiową wzmocnionych wysokostopowymi drutami stalowymi. Na podstawie wyników badań metalograficznych, wytrzymałościowych oraz analitycznych wykazano przydatność wykorzystania energii wybuchu do wytwarzania kompozytów z aluminium wzmacnianego drutami stalowymi oraz zaproponowano kierunki dalszych badań.
EN
The energy of explosion can be used to implement a number of processes, including manufacturing of explosion welded joints, pressing powders, press forming, annealing and hardening of metals. Highly interesting application for explosion welding technology is the production of metal composites. The article characterizes the metal composites and explosion welding as one of the methods for obtaining them. An original technology of obtaining metal composites with aluminum matrix strengthened with steel wires was presented. Based on the results of metallographic, strength and analytic tests the suitability of the use of energy of explosion to produce composites of aluminum strengthened with steel wires was demonstrated and directions for future research were suggested.
EN
The aim of the study was to determine the influence of the solid particles density and size on their distribution in the solidified cast. As part of the work, a series of numerical simulations of filling and solidification process were made with the use of FLOW-3D software. The analysis was performed on pure aluminum and six chosen types of particles with different size and density. Obtained results may help to understand the behavior of solid particles in liquid metals.
EN
Composite materials gain more and more applications thanks to their specific properties and possibilities of shaping of products made out of them. One of the product forming technologies is cutting. Although most metal matrix composites are ready for use after volume shaping e.g. by casting, it is worth to define also possibilities of processing these materials also by this technology. This paper presents possibilities of cutting metal matrix composites and compares existing methods and their application range. The laser cutting of metal matrix composites reinforced with hard ceramic fiber was of particular interest in this work. Preliminary process parameters were determined and quality of obtained cut edges was compared with basic material of the aluminum matrix. This comparison proved that presence of reinforcement negatively affects the quality of the cut surface. However, the laser cutting process is efficient and it allows elastic shaping of metal matrix composites reinforced with hard ceramics.
EN
Bending strength, thermal and electric conductivity and microstructure examinations of Cu based composite materials reinforced with Saffil alumina fibres are presented. Materials were produced by squeeze casting method applying the designed device and specially elaborated production parameters. Applying infiltration pressure of 90MPa and suitable temperature parameters provided manufacturing of copper based composite materials strengthened with Saffil alumina fibres characterized by the low rest porosity and good fibre-matrix interface. Three point bending tests at temperatures of 25, 100 and 300ºC were performed on specimens reinforced with 10, 15 and 20% of Saffil fibres. Introduced reinforcement effected on the relatively high bending strengths at elevated temperatures. In relation to unreinforced Cu casting strength of composite material Cu – 15vol.% Saffil fibres increase by about 25%, whereas at the highest applied test temperature of 300ºC the improvement was almost 100%. Fibres by strengthening of the copper matrix and by transferring loads from the matrix reduce its plastic deformation and hinder the micro-crack developed during bending tests. Decreasing of thermal and electrical conductivity of Cu after incorporating fibres in the matrix are relatively small and these properties can be acceptable for electric and thermal applications.
EN
In the present work copper was strenghtened with 20 and 30 vol. % of alumina particles characterized by diameter of 3-6μm. The copper based composite materials were manufactured by the squeeze casting method. Preheated preforms made from Al2O3 particles were placed in the desired place in the heated cast die and the squeeze casting process with liquid copper was performed applying the infiltration pressure of 90MPa and pressure was kept for 10-15s until solidification was complete. The microstructure and physical properties: Brinell hardness (HBW) and density were characterized. Metallografic examinations showed that alumina particles were uniformly distributed in the copper matrix. Hardness of 208 HBW for composite materials containing 30 vol.% of particles was achieved. Wear investigations were performed applying the tribological pin-on-disc tester. Friction forces between copper based composite materials containing 20 and 30 vol. % of Al2O3 particles and cast iron were registered and wear was determined on the base of the specimen mass loss after 1.0, 3.5 and 8.5 km friction distance.
EN
AM50/Mg2Si composites containing 5.7 wt. % and 9.9 wt. %. of Mg2Si reinforcing phase were prepared successfully by casting method. The microstructure of the cast AM50/Mg2Si magnesium matrix composites was investigated by light microscopy and X-ray diffractometry (XRD). The microstructure of these composites was characterized by the presence of \alfa-phase (a solid solution of aluminium in magnesium), Mg17Al12 (\gamma-phase), Al8Mn5 and Mg2Si. It was demonstrated that the Mg2Si phase was formed mainly as primary dendrites and eutectic.
PL
Jakość odlewów kompozytowych jest uwarunkowana wieloma czynnikami. W pracy przedstawiono wpływ wybranych parametrów nasycania kształtek zbrojących metalowe odlewy kompozytowe, takich jak temperatura i ciśnienie oraz wpływ struktury zbrojenia na stopień nasycenia a przez to porowatość badanych materiałów. Stwierdzono, iż w przypadku nasycania próżniowego największy wpływ na stopień nasycenia wytworzonych kompozytów ma porowatość zbrojących je kształtek. Dokonano również analizy wpływu stopnia nasycenia na wytrzymałość wybranych materiałów kompozytowych oraz porównano charakter ich niszczenia z charakterem niszczenia czystego stopu wykorzystywanego jako osnowa badanego kompozytu. Analiza objęła także określenie wpływu stopnia nasycenia kształtek zbrojących na uzysk metalu osnowy podczas procesu recyklingu kompozytów.
EN
Quality of composite castings is conditioned by many factors. This paper presents the impact of selected parameters of saturation of preforms reinforcing the metal-matrix composite castings, such as temperature, pressure and reinforcement structure, on degree of saturation and – consequently – porosity of examined materials. It was found that for the vacuum saturation, a saturation degree of produced composites is influenced mostly by porosity of the reinforcing preforms. An analysis of influence of the saturation degree on strength of selected composite materials was also conducted and character of their destruction was compared with character of destruction of a pure alloy used as a matrix of the examined composite. The analysis also included determination of the influence of reinforcement preforms saturation degree on yield of the matrix metal during the process of the composite recycling.
EN
Cellular structures are characterized by a number of unique properties that can be successfully utilized in the construction of machines and vehicles. Their low density makes them an ideal filling material for laminated structures. The use of the proper method of foam production affects its structure (e.g. the distribution, openness and size of pores, wall thickness between pores etc.), consequently the material properties are affected. Another important issue is the material itself used for metal foam production, as materials meeting increasingly new requirements are being sought, among which are metal composite materials. This work presents theoretical considerations referring to foam making by comparing the water system to a real foam production system.
EN
AZ91 magnesium alloy matrix composites with aluminosilicate glass cenospheres were fabricated successfully by the pressure infiltration method. Different parameters of the fabrication process, such as temperature of the mould and temperature of cenospheres were used. Influence of the temperature variation of particular parameters on the microstructure has been investigated. The microstructure of AZ91 magnesium alloy and fabricated composites have been investigated by light microscopy (LM) and scanning electron microscopy (SEM). The results revealed that AZ91 magnesium alloy consists of α-Mg matrix and eutectic α-Mg17Al12 and a small amount of discontinuous precipitates of γ phase. The microstructure of matrix AZ91 in fabricated composites is characterized also by the presence of α-Mg matrix and eutectic α-Mg17Al12. However, in the composite fabricated by using the mould heated to 500 °C more discontinuous precipitates of γ phase were observed.
EN
As it is known a foam made of composite with aluminium alloy matrix and SiC particles reinforcement does not reach the liquid state even at a temperature over 1000oC. The causes of such behaviour of foam have been examined. It has been found that it is due to two phenomena. One is connected with the creation of continuous layer of oxides at the boundary of gaseous pores and liquid metallic phase. The other is an increase of the apparent viscosity of solids suspended in liquid metal along with an increased content of these inclusions to the point where the suspension loses its continuity.
EN
Properties of composites made through saturation of ceramic reinforcement preforms with liquid metal are the cause of growing use of these materials. Taking increasing requirements regarding environment protection into consideration, already during design of such materials one should think of a way of their recycling at the end of life. The recycling of these materials is conducted by separation of components. Determining optimal superficial conditions of a recycling system: liquid metal matrix – reinforcement preform – medium enables automatic course of the recycling process, but does not guarantee high yield of metal. With identical superficial conditions of the recycling system and different structure of reinforcement preforms significant differences in metal yield can be obtained. Identification of a type of a capillary present in reinforcement preforms may allow to determine, already during stage of material design, which types of composites will undergo the recycling process better and for which types one has to accept decreased yield of matrix metal. This identification can be done on the basis of an analysis of results obtained during examination conducted with mercury porosimetry, comparing acquired hysteresis graphs with model graphs proposed by de Boer for adsorbent analysis. Considering the analysis of image of structure of examined reinforcement preforms makes the identification process easier and faster.
EN
The main characteristic of aluminosilicate glass cenospheres and their possible use as a component of magnesium matrix composites were presented. The results revealed that particular parts of cenospheres differ insignificantly from each other and it depends on which power plant cenospheres come from. The characteristic of cenospheres concerned their structure and phase composition and dimensions such as: wall thickness and size of pores occurring in walls, depending on cenospheres origin. Thickness of cenospheres walls and pore size were measured by using ImageJ computer software. The structure of aluminosilicate glass cenospheres and their phase composition have been investigated by scanning electron microscopy and X-ray diffraction (XRD). The possibility of cenospheres utilization in the fabrication of magnesium matrix composites was presented on the example of AZ91 magnesium alloy composite with fly ash cenospheres. Composite was fabricated by pressure infiltration method.
EN
Metal matrix composite materials were manufactured by squeeze casting with CuZn38Al2Mn1Fe brass of porous preforms made of δ-alumina SAFFIL fibres. The microstructure, Brinell hardness and Vickers microhardness of manufactured composite materials were characterized. Preforms with 10 and 20 vol. % of fibres were preheated and infiltrated applying the pressure of 80 MPa. Microscopic observations showed that alumina fibres are uniformly distributed in the MA58 matrix and there was not observed the destroying of ceramic fibres during squeeze casting process. Hardness of composite materials strengthened with 20 vol.% of SAFFIL fibres reached 265 HB. At the boundary of composite material/not strengthened MA58 alloy it was ascertained the filtration and retention of iron compound precipitates caused by the small dimensions of pores in the ceramic preform. The collection of iron phase precipitates at the boundary composite material/ not strengthened MA58 alloy effected in the increase of microhardness in this zone to 352 HV. On the base of SEM observations the conclusion on limited wettability of fibres by liquid MA58 brass was drawn.
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