Metoda zol-żel jest stosowana w Instytucie Technologii Materiałów Elektronicznych (ITME) do otrzymywania nanoproszków wieloskładnikowych tlenków. W pracy jest opisane znaczenie nanoproszków dla zastosowań w optoelektronice i fotowoltaice. Przedstawiono opis procesu metody zol-żel na przykładzie granatu Y3Al5O12 (YAG). Wykazano, że proces zachodzi na drodze reakcji chemicznej w niskiej temperaturze i temperaturze prażenia ok. 1000°C. W rezultacie otrzymuje się materiały bardzo czyste, o wysokiej stechiometrii. Omówiono badania luminescencji dla YAG:Nd oraz Y4Al2O9 (YAM):Yb i Nd i GdCa4O(BO3)3 (GdCOB):Eu. Pokazano, że czasy zaniku luminescencji badanych nanoproszków są dłuższe niż te obserwowane w monokryształach. Szczegółowe wyniki są przedstawione w cytowanych publikacjach.
EN
The sol-gel method is used to obtain nanopowders of polycomponent oxides at Institute of Electronic Materials Technology. The role of nanopowders in optoelectronics and photovoltaic technology is described. The garnet of Y3Al5O12 (YAG) is used to describe the details of sol-gel procedure. It is shown that the process is going by chemical reactions at low temperature and annealing at about 1000°C. Nanopowders of compound are very high purity and stoichiometry. Some results of luminescence of YAG:Nd, Y4Al2O9 (YAM):Yb and Nd and GdCa4O(BO3)3 (GdCOB):Eu are presented. It is shown that decay life times are longer for nanopowders than these for single crystals. The detailed results are presented in our cited publications.
Podano podstawowe definicje, omówiono rozwój nanotechnologii i jej podstawowe obszary badawcze. W rozważaniach odniesiono się do inżynierii materiałów budowlanych, w tym technologii betonu.
EN
The basic definitions are given, the development of nanotechnology and its principle areas of research are discussed. The considerations are oriented on engineering building materials incuding concrete technology.
W artykule przedstawiono genezę, obserwowanego w ostatnich latach, dynamicznego rozwoju nanotechnologii na świecie, zapoczątkowanego w Stanach Zjednoczonych ze względu na największe skupienie potencjału naukowego i kapitałowego. Omówiono rodzaje nanomateriałów i ich już wdrożone zastosowania techniczne, przede wszystkim w dziedzinach: elektroniki, informatyki i medycyny, a także przewidywane, możliwe zastosowania, będące obecnie przedmiotem badań. Ponadto przedstawiono krótkoterminową prognozę rozwoju nanotechnologii. Zaprezentowano także badania własne autora w obszarze tribologii, polegające na stosowaniu nanocząstek metali, jako dodatków modyfikujących tribologiczne właściwości środków smarowych.
EN
The paper presents a genesis of observed in last years dynamic development of nanotechnology originated in USA because of biggest concentration of scientific and capital potential. Types of nanomaterials are discussed and their technical applications first of all in the fields of electronics, informatics and medicine, and also predicted, possible applications which are now in examinations are presented. A short term prognosis of nanotechnology development is presented as well. On above background the author own examinations are showed also in the area of tribology, consisting in metal nanoparticles using as additives modifying tribological properties of lubricating and cutting oils.
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Nanosized materials (nanoparticles, nanocrystals, quantum dots) have different properties than their conventional coarse-grained polycrystalline or bulk counterparts. The most characteristic feature of nanocrystals is the existence of the grain size-driven structural phase transitions. The literature data on such phase transitions are collected in the form of database. Different types of phase diagrams ,"grain size - temperature" are proposed and discussed.
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Some metallic alloys, and especially the ceramic-metallic ones, are produced using mechanical methods only by application of mechanical devices – mills. These mechanical methods are applied mostly for production of amorphous alloys, however in many cases they are also applied for production of crystalline alloys. These methods are specifically applied for production of metallic nano-materials and high-purity metals. These methods include: mechanical alloying (MA), high energy ball milling (HEBM) or reactive milling (RM). These methods use mainly the vibratory, planetary, mixing, impeller, rotary-magnetic, gravitational or rotary-vibratory free grinding medium mills. This paper presents operation principles, basic technical parameters and some design solutions of these mills. It includes also an application example of the rotary-vibratory mill for production of the nickel and zirconium or pure nickel crystalline alloys and also the amorphous Ni50Zr50 alloy.
PL
Niektóre stopy metaliczne oraz metaloceramiczne, wytwarzane są tylko metodami mechanicznymi z zastosowaniem urządzeń mechanicznych – młynów. Największe zastosowanie metody mechaniczne znalazły przy wytwarzaniu stopów amorficznych, chociaż w wielu przypadkach stosuje się je przy wytwarzaniu stopów krystalicznych. Szczególne zastosowanie mają te metody przy wytwarzaniu nanomateriałów metalicznych i otrzymywaniu metali o bardzo wysokiej czystości. Wśród tych metod wyróżnić można: mechaniczną syntezę (MA), wysokoenergetyczne mielenie (HEBM) oraz reaktywne mielenie (RM). W metodach tych stosuje się głównie młyny z mielnikami swobodnymi: wibracyjne, planetarne, mieszadłowe, wirnikowe, obrotowo-magnetyczne, grawitacyjne i obrotowo-wibracyjne. W pracy przedstawiono sposoby działania tych młynów, ich podstawowe parametry techniczne oraz niektóre rozwiązania konstrukcyjne. Podano również przykład zastosowania młyna obrotowo-wibracyjnego w wytwarzaniu stopów krystalicznych: niklu z cyrkonem oraz czystego niklu, a także stopu amorficznego Ni50Zr50.
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W artykule przedstawiono wyniki badań mechanicznych i obserwacji mikrostruktury miedzi i technicznego tytanu poddanych plastycznej przeróbce metodą wyciskania w kanale kątowym (ECAP), walcowania pakietowego ze spajaniem (ARB) oraz skręcania pod wysokim ciśnieniem (HPT). Porównano rozdrobnienie ziarna uzyskane tymi trzema metodami. Największe rozdrobnienie ziarna uzyskano metodą skręcania (HPT) pod ciśnieniem 2 GPa.
EN
Three methods of intensive (severe) plastic deformation, i.e. Equal-Channel Angular Pressing (ECAP), Accumulative Roll-Bonding (ARE) and High Pressure Torsion (HPT), were used to
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In this investigation Ti-SiC>2 (3, 10 vol%) nanocomposites were produced by the combination of mechanical alloying (MA) and powder metallurgical process. The resulting microstructures were characterized using X-ray difFraction, scanning eleclron microscope with energy dispersive X-ray spectrometry and transmission electron microscopy. The properties of the nanocomposites were investigated by mechanical, corrosion and biocompatibility studies. The experimental results show, that Ti-SiOi nanocomposites have good corrosion resistance and biocompatibility in comparison with microcryslalline titanium. Vickers' microhardness of Ti-10 vol% Si02 nanocomposites is 650 HV0.2 (pure Ti metal - 225 HV0.2). In conclusion, titanium - ceramics nanocomposite are suitable for hard tissue replacement from the point of view of both mechanical and corrosion properties.
PL
Celem niniejszej pracy było wytworzenie nanokompozytowych biomateriałów typu Ti-SiC>2 (3, 10% wag.) metodą mechanicznej syntezy i metalurgii proszków. Mikrostruktura wytworzonych kompozytów była badana przy użyciu dyfrakcji promieni rentgenowskich, skaningowego mikroskopu elektronowego z mikroanalizatorem rentgenowskim i transmisyjnego mikroskopu elektronowego. Zbadano również własności mechaniczne, odporność korozyjną i biokompatybilność otrzymanych kompozytów. Z przeprowadzonych badań wynika, że nanokompozyty typu Ti-SiOi posiadają lepsze własności mechaniczne (mikrotwardość Vickersa dla Ti-10% Si02 wynosi 650 HV0.2 a dla tytanu 225 HV0.2), wyższą odporność korozyjną i biozgodność w porównaniu do mikrokrystalicznego tytanu. Z tego względu, nanokompozyty tytanowo - ceramiczne mogą stać się perspektywicznymi biomateriałami do zastosowań na implanty medyczne.
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Purpose: One of the methods of plastic deformation under complex deformation path conditions is compression with oscillatory torsion. The observable effects in the form of changing force parameters and structure changes confirm the possibility of deformation to a value many times higher than in the case of methods traditionally applied for forming. This article presents the results of the influence of compression with oscillatory torsion on structural phenomena occurring in copper deformed in such a way. Design/methodology/approach: The examinations were conducted at a compression/oscillatory torsion test stand. The structural examinations were conducted with the use of light and electron microscopy. Findings: In experimental investigations, a reduction of unit pressures was observed when compared to conventional compression. The structural examinations indicated substantial differences in the mechanisms of plastic deformation conducted in both conventional and combined way. Research limitations/implications: There are premises which show that a metallic material of a nanometric structure can be obtained in this way (top-down method), by the accumulation of great plastic deformation. Metallic materials characterized by grain size below 100nm are distinguished by unconventional properties. Further examinations should focus on conducting experiments in a way that would enable grain size reduction to a nanometric size. This will enable the cumulation of greater deformation in the material. Originality/value: The method of compression with oscillatory torsion is an original method developed at the Silesian University of Technology, owing to which it is possible to obtain high deformation values (SPD) without risking the loss of cohesion of the material. Thorough understanding of the changes taking place in the structure of metals subjected to compression with oscillatory torsion will allow the optimal choice of process parameters in order to achieve a gradual grain size reduction.
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Purpose: The purpose of the presented work is to study the influence of different Si3N4 and SiC powders on mechanical properties of Si3N4-SiC composites, to obtain a hard and tough engineering material, especially for cutting applications. Design/methodology/approach: Three kinds of Si3N4 - SiC composite, with initial powders of different grain size: micro-, submicro- and nano-structured, were sintered by the HPHT (High-Pressure High-Temperature) method. Several variants were made of each composite, with different Si3N4 to SiC phase volume ratios. The influence of grain size of the initial Si3N4 and SiC powders on mechanical properties of sintered materials was investigated. Density, Young's modulus, hardness and fracture toughness of composites were measured. Microstructural (SEM) investigations were also conducted for selected samples. Findings: A strong influence of initial powder size on mechanical properties of Si3N4 - SiC composites can be observed. Sintered materials obtained from submicron powders are characterized by better mechanical properties than those obtained from micro- and nanopowders. Research limitations/implications: The material obtained is characterized by a good combination of hardness and fracture toughness, but further improvement in toughness is possible by the addition of third phase dispersion particles to the Si3N4 - SiC system. Practical implications: A practical aspect of the research carried out is an improvement in mechanical properties of silicon nitride and silicon carbide-based composites. Following additional technical exploitation tests, the materials obtained could be used in cutting tools, various parts of machines and wear components. Originality/value: The composites obtained have a better combination of mechanical properties than comparable commercial materials.
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Istotnym etapem w procesie przetwarzania nanoproszku ceramicznego w produkt końcowy jest zapobieganie utracie jego potencjalnych wyjątkowych właściwości - co rozumie się jako zapobieganie utracie nanometrowych rozmiarów cząstek proszku (a potem ziaren w produkcie finalnym). Tę trudną sztukę warto połączyć z mało skomplikowaną technicznie metodą formowania wyrobów [1] - np. techniką slip casting, czyli metodą odlewania mas lejnych do form porowatych. Celem, do którego należy dążyć przy zastosowaniu tej techniki jest konieczność uzyskania stabilnej i zdeaglomerowanej zawiesiny cząstek proszku charakteryzującej się optymalną dla metody wartością parametru lepkości. Starając się spełnić wymagania wymienione powyżej, w badaniach przeprowadzonych nad procesem upłynniania mas lejnych z nanoproszku AI2O3(30%obj.) jako środki dyspergujące zastosowano di-i oligosacharydy wprowadzone w ilościach 0,19%wag. i 1%wag. (w przeliczeniu na masę proszku ceramicznego): sacharoza, maltoza (dwucukry) oraz β-cyklodekstryna (cykliczny oligosacharyd). Zastosowanie tych związków - choć podobnych w budowie chemicznej - skutkowało znacznymi różnicami w parametrach reologicznych badanych gęstw. Jednocześnie przeprowadzone pomiary wielkości aglomeratów w masach nie wskazały, by wprowadzenie któregoś z analizowanych upłynniaczy drastycznie wpłynęło na rozmiar zawieszonych cząstek. Takie obserwacje mogą wskazywać na bardzo skomplikowany i zarazem ciekawy mechanizm upłynniania nano-AI2O3 w układzie wodnym - tj. zależność właściwości reologicznych układu nie tylko od charakteru chemicznego wprowadzonych dodatków (i oddziaływań o charakterze stricte chemicznym), ale najprawdopodobniej także od subtelnych interakcji na poziomie struktury rozważanej dyspersji.
EN
Prevention of the loss of nanometric size of nanopowder particles is a crucial point during powder processing into the final item. It is worth to combine this difficult task with a technically easy way of product forming [1] - method of slip casting. The objective which is to be gained using this method is the stable, deagglomerrated and deaggregated suspension of powder particles. The slurry should also have an optimal viscosity parameter and it is important for the additives to be soluble in water, nontoxic and environment friendly. To meet the requirements mentioned above, di- and oligosaccharides were used as plasticizers for AI2O3 (30 vol%) nanoparticle slurries (water dispersions). Saccharides, saccharose, maltose (disaccharides) and β-cyclodextrin (cyclic oligosaccharide) were applied in low concentrations: 0.19 wt% and 1 wt% (in relation to ceramic powder mass). The use of these sugars- similar of chemical constitution - produced considerable differences in rheological parameters of the examined slurries. It is also important to emphasize that the incorporation of any substance mentioned did not result in reduction of size of the suspended agglomerates. These observations may indicate that there is very complicated and interesting plasticizing mechanism of nano-Al2O3 water slurries - i.e. the system rheological properties dependence on chemical character of loaded substances (and stride chemical influence), but probably also on subtle interactions on dispersion structure level.
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Purpose: In the combat vehicles many materials can be used for the armour. Application of the monolithic armour plates in light combat vehicles is limited by the high armour weigh. Introduction of the layered armour plates is a way to limit the vehicle weight. In the paper test results of graded and nanostructural GMA surfaced armour plates are presented. Design/methodology/approach: Metallographic structure, chemical composition and hardness of surfaced layers were investigated in order to examine the influence of the layered armour plate construction on penetration failure mechanism. EDS chemical microanalysis was carried out on the cross section of surfaced armour plates to find the correlation between the structure components distribution, a GMA surfaced layer thickness and the armour plates ballistic resistance. Findings: The experimental tests confirmed a high ballistic resistance of the GMA surfaced armour plates against B-32 armour-piercing incendiary projectile. The special microstructure of nanostructural deposited metal provides high hardness and resistance against impact load. Practical implications: In order to achieve a high ballistic resistance of GMA surfaced armour, nanostructural layer thickness of at least 4.5 [mm] is needed. To optimize the armour plate weight and high ballistic resistance the ratio of soft austenite under-layer thickness and total armour plate thickness need to be tested. Originality/value: The special microstructure of nanostructural deposited metal, provides high hardness and resistance against impact load.
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Purpose: of this paper is to present the research results of silicon nitride SiNx films used for industrial silicon solar cells and for third generation solar cells. Design/methodology/approach: The SiNx films were deposited using RF- and LF-PECVD methods. The optical and structural properties were investigated by spectroscopic ellipsometry, XPS, FTIR spectroscopy and X-Ray reflectometry. The passivation properties were investigated by carriers lifetime measurements using a photoconductance decay (PCD) technique. For the photovoltaics of third generation the multilayer structures of SiNx were deposited and annealed in order to obtain the silicon quantum superlattices. These structure were characterized by high-resolution TEM, GI-XRD, photoluminescence, Raman and SPV spectroscopy. Findings: It is shown that the layers deposited by LF PECVD have more profitable optical and electrical properties for industrial silicon solar cells than those deposited by RF PECVD. The other finding is that multi-layer structure of SiNx annealed at high temperature shows the properties of the new semiconductor with the gap energy broader then the gap of the silicon. Research limitations/implications: The maximal density of SiNx layers is equal to 2.6 g/cm3. It is too low to obtain high efficiency mc-Si cells. The deposition process should be further optimized. The other limitation is obtaining a regular structure of quantum superlattice composed of quantum dots with defined diameter and density which is a very difficult technological task. This work should be continued in the future. Practical implications: The results of SiNx investigation can be used to increase the efficiency of mc-Si solar cells. The results of multilayer SiNx investigations may be applied to a solar cells based on silicon QDs superlatice. Originality/value: The work present useful methods for optimisation of passivation properties of SiNx films. The other value of the paper is obtaining new kind of nanomaterial composed of Si quantum dots embed in the dielectric matrix.
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W artykule przedstawiono charakterystykę stosowanych w Instytucie Metalurgii Żelaza metod otrzymywania materiałów metalicznych o strukturze nanometrycznej oraz wstępne wyniki badań uzyskanych w ramach projektu zamawianego Technologie wytwarzania wyrobów z metali i stopów o strukturze nanometrycznej, finansowanego przez MNiSW. Badania nanomateriałów w Instytucie są prowadzone w trzech dziedzinach badawczych: wytwarzanie nanokrystalicznych stopów metodą mechanicznej syntezy, kształtowanie ultradrobnoziarnistych i nanokrystalicznych struktur metali metodą skumulowanego odkształcania plastycznego za pomocą symulatora Glceble 3800 z jednostką MAX-Strain oraz otrzymywanie ultradrobnoziarnistych struktur metali metodą odkształcania plastycznego przez skręcanie pod hydrostatycznym ciśnieniem.
EN
The description of the methods of the preparation of nanostructured metallic materials in Institute for Ferrous Metallurgy is given. Some preliminary results of research studies obtained within goal orientated project Techniques of preparation of nanostructured metallic and alloyed parts, sponsored by Ministry of Science and Higher Education, are presented. The studies on nanomaterials in the Institute for Ferrous Metallurgy are performed in three research fields: preparation of nanocrystalline alloys by mechanical alloying technique, forming the ultra-fine grained and nanocrystallinc metals' structures by cumulative plastic deformation in Glecble 3800 simulator with MAX-Strain unit and obtaining ultra-fine grained metals' structures by plastic torsional straining under hydrostatic pressure.
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W artykule przedstawiono podstawy teoretyczne formowania tworzyw ceramicznych metodą odlewania, w której masa lejna odwzorowuje powierzchnię porowatej formy. Metoda odlewania jest metodą znaną i chętnie stosowaną w technologii ceramiki, w produkcji wyrobów sanitarnych oraz ceramiki stołowej. Jednakże trwają badania nad rozszerzeniem zastosowania tej metody przy produkcji "zaawansowanej ceramiki", tj.: do otrzymywania nanomateriałów i kompozytów ceramika-metal. W celu otrzymania masy lejnej o optymalnych właściwościach, gwarantującej otrzymanie wyrobów pozbawionych defektów, wprowadzane są odpowiednie dodatki, tj.: uptynniacze, spoiwa oraz środki powierzchniowoczynne. W artykule opisano rolę poszczególnych składników masy oraz opisano mechanizmy upłynniania proszków ceramicznych.
EN
In the paper, basic principles of slip casting are presented. Slip casting is a forming method in ceramic technology in which ceramic slurry poured into a porous mould replicates its negative. This method is well known and widely used in ceramic technology, in the manufacture of sanitaryware and tableware. However, the slip casting method may find application in production of advanced ceramic materials where research is carried out concerning the use of this forming method in obtaining nanomaterials and ceramic-metal composites. In order to obtain slurry of the most beneficial properties - leading to obtaining ceramic bodies without defects - some additives are introduced into it. Generally additives are as follows: deffloculants, binders and surface active agents. In the paper, the role of each ingredient is described. Mechanisms of deflocculation of ceramic powder in liquid medium are described.
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Radiation chemistry is a part of the physical chemistry similary like photo-chemistry, plasma-chemistry, ultrasonic-chemistry etc. Ionizing radiation produces abundant secondary electrons. Following these primary events, the ions, secondary electrons and excited molecules undergo further transformations, exchanging charges and energy and reacting with surrounding molecules, thereby producing free radicals and other reactive species which finally evolve into new stable products. Three main sources of radiation are applied for radiation processing]. These are electron accelerators], gamma sources and X-ray unit based on e-/X conversion process. Radiation processing was used early on for polymer modification. The intermediates formed during material irradiation can follow several reaction paths that result in disproportion, hydrogen abstraction, arrangements and/or the formation of new bonds. Nowadays, the modification of polymers covers radiation cross-linking, radiation-induced polymerization (graft polymerization and curing) and the degradation of polymers. Some polymers predominantly undergo crosslinking other degradation. However new techniques allow crosslinking of polymers which were considered to be degradable only, like PTFE and cellulose derivatives. Regarding natural polymers the biggest application concerns rubber pre-crosslinking in tire industry. The processing of natural polymers is also being developed to elaborate new biodegradable materials. The radiation crosslinked wires and cables show excellent heat resistance (long-term thermal stability and short-term thermal stability) as well as abrasion resistance. Other big application is crosslinking of XLPE type pipes which are widely used for hot water and floor heating. Polybutelene terephtalate (PBT), which is a plastic for electronic industry, can be crosslinked by radiation and lead free soldering materials can be applied in such a case. This method of crosslinking is also applied to manufacture thermoshrinkable tubes and types possessing "memory effect". Through radiation, grafting metal adsorbents and ion exchange membranes can be developed. Radiation is early applied tool in the area of nanomaterials engineering; arrangement of atoms and ions has been performed using ion or electron beams for many years. New trends concern surface curing and development of ion track membranes and controlled release drug-delivery systems. Finally, radiation processing concerns gem stones colorization, development of high temperature resistant fibers (SiC) and semiconductor modification. Over the past few years, radiation processing technologies aimed at ensuring the safety of gaseous and liquid effluents discharged to the environment have been developed. It has been demonstrated that radiation processing based technologies for flue gas treatment (SOX and NOX removal), wastewater purification, and sludge hygienization can be effectively deployed to mitigate environmental degradation. Electron beam technology is among the most promising advanced technologies of new generation. This is a dry-scrubbing process of simultaneous SO2 and NOx removal, where no waste except the fertilizer by-product are generated.The other possibility is application of the process for VOC removal. Tests at the pilot plant constructed at a coal-fired power station were performed with the purpose of estimating the influence of electron beam on VOCs present in flue gas, during SO2 and NOx removal. The removal efficiencies have been ranged from 40% up to 98%. The chlorocarbons including dioxins may be removed with high efficiency as well. During the radiolysis of water reactive radicals of strong oxidizing or reducing properties are formed that can transform the pollutants in the liquids wastes. A large number of substances such as hard surfactants, lignin, pesticides cannot be degraded by conventional biochemical methods and thus escape from decomposition in biological treatment. Research and industrial treatments testify significant improvement of pollutant biodegradability after radiation-oxidation in aerated wastewater.
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