Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 29

Liczba wyników na stronie
first rewind previous Strona / 2 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 2 next fast forward last
EN
This is a second part of the article in which the authors attempt to present the courses of action of the Territorial Defence Forces’ subunits in the conditions requiring the support of state and territorial administrations when life of residents is jeopardized as a result of catastrophes and natural disasters. This is one of the key tasks faced by the newly established Territorial Defence Forces (WOT) that is the protection of people and property within the activities unrelated to the kinetic impact of potential enemies.
EN
The basic method of surface protection for aviation engine components manufactured from nickel super alloys is diffusion aluminization. There are four methods of forming aluminide coatings: pack cementation, above the pack, slurry, and chemical vapor deposition (CVD). The aluminide coatings are modified with various elements, e.g. Pt, Pd, Hf, Zr, Si, Cr, Y, etc. The paper show results of experiments on the use of electrochemical processes in which the modifying elements are introduced in the form of powder for galvanic bath. These processes have been combined with low-activity and high-activity aluminization, as well as zircon doping in the CVD process. It has been shown that the aluminide coatings formed in the high-activity process are characterized by Al>50% at. content. The aluminide coatings formed in the low-activity process were composed of an outer zone composed of a NiAl phase with an aluminum content <50% at. and the diffusion zone. The aluminide coatings formed during low-activity zircon doping have similar structure. The content of elements introduced with nickel was low (up to several %), which does provide for a desired increase in heat resistance of the modified coatings.
PL
Aluminiowanie dyfuzyjne jest podstawowym procesem wprowadzonym do ochrony powierzchni elementów części gorącej silników lotniczych wytwarzanych z nadstopów niklu. Warstwy aluminidkowe wytwarzane są w procesach: kontaktowo-gazowym (ang. pack cementation), gazowym bezkontaktowa (ang. above the pack), zawiesinowowym (ang. slurry) i chemicznym osadzaniu z fazy gazowej CVD (ang. Chemical Vapour Deposition). Warstwy aluminidkowe dla zwiększenia ich żaroodporności modyfikowane są pierwiastkami m.in. Pt, Pd, Hf, Zr, Si, Cr, Y. W artykule przedstawiono analizę wyników badań warstw aluminidkowych, w których pierwiastki modyfikujące wprowadzono w postaci proszku do kąpieli galwanicznej w trakcie procesu niklowania. Procesy te połączono z aluminiowaniem nisko- i wysokoaktywnym, a także cyrkono-aluminiowaniem w procesie CVD. Wykazano, że warstwy aluminidkowe wytworzone w procesie wysokoaktywnym charakteryzują się zawartością Al >50% at. W warstwie aluminidkowej wytworzonej w procesie niskoaktywnym wyodrębniono strefę zewnętrzną - kryształów fazy NiAl o zawartości Al <50% at. oraz strefę dyfuzyjną. Zbliżoną budowę miały warstwy aluminidkowe wytworzone w trakcie cyrkono-aluminiowania niskoaktywnego. Stwierdzono małe zawartości pierwiastków wprowadzanych wraz z niklem (do kilku %).
EN
The authors attempt to present in the article the courses of action of the Territorial Defence Forces’ subunits in the conditions requiring the support of state and territorial administrations when life of residents is jeopardized as a result of catastrophes and natural disasters. This is one of the key tasks faced by the newly established Territorial Defence Forces (WOT) that is the protection of people and property within the activities unrelated to the kinetic impact of potential enemies.
EN
In the paper the comparison of open porosity measurement results of ceramic topcoats in thermal barrier coatings (TBCs) was presented. TBCs were produced by Air Plasma Spraying (APS) method and were consisted of two coatings – an outer ceramic topcoat and metallic MeCrAlY bond coat deposited onto surface of René80 Ni-based superalloy. For deposition of ceramic coatings Metco 201 B NS, Metco 204 NS and Metco 210 powders were used whereas for deposition of metallic bond coat AMDRY 365-1 MeCrAlY powder was used. Both types of coatings were deposited using Thermico A60 plasma gun. The microstructure investigations of cross-sections of produced TBC’s were carried out using Hitachi S-3400N scanning electron microscope. Qualitative image analysis of microstructure of produced TBCs as well as analysis of percentage of pores surface area content AA was performed. The evaluation of porosity in ceramic topcoat was carried out by image analysis using MeTilo v.12.1 quantitative software.
PL
W pracy przedstawiono analizę wyników badań porowatości otwartej w zewnętrznej warstwie ceramicznej powłokowej bariery cieplnej TBC. Międzywarstwę metaliczną wytworzono przy użyciu proszku AMDRY 365-1, natomiast warstwę ceramiczną przy zastosowaniu proszku Metco 201 B NS, Metco 204 NS i Metco 210 firmy Oerlikon Metco. Warstwy natryskiwano za pomocą jednoelektrodowego palnika plazmowego A60 firmy Thermico, w warunkach ciśnienia atmosferycznego (APS) na podłożu nadstopu niklu René 80. Badania mikroskopowe powłokowych barier cieplnych TBC prowadzono przy użyciu skaningowego mikroskopu elektronowego Hitachi S-3400N. Wykonano analizę jakościową obrazów mikrostruktury oraz określono pole powierzchni przekroju płaskiego porów otwartych. W ocenie porowatości zewnętrznej warstwy ceramicznej stosowano program komputerowy do ilościowej analizy obrazu MeTilo v.12.1.
PL
W pracy zamieszczono wybrane wyniki badań dotyczące modelowania neuralnego rozwoju systemu elektroenergetycznego na bazie danych testowych IEEE RTS 96., m.in.: sposób tworzenia macierzy danych wejściowych oraz wyjściowych, sposób doboru parametrów sieci, itp. W wyniku projektowania i uczenia SSN uzyskano modele rozwoju SEE, które poddano badaniom wrażliwości m.in. na zmianę liczby warstw ukrytych oraz liczby neuronów w warstwie.
EN
The paper presents selected results of research on the modeling of neural development of the power system test data based on the IEEE RTS 96, m.in .: how to create a matrix of data input and output, how to select the network parameters and the like. As a result of learning design and development of the ANN models were obtained SEE, which has been tested sensitivity among to change the number of hidden layers and the number of neurons in a layer.
EN
The paper presents selected results of research on the design of artificial neural networks and training them using the electrical power system development model (EPS or EP system) based on IEEE RTS 96 test data, i.a. creation of training and test files, development of architecture of the artificial neural network, selection of parameters of the network, selection of appropriate training and testing method, etc. As a result of the development and training an ANN, the following EP system development models were obtained, which were examined for sensitivity to changes of the number of hidden layers, number of neurons in a layer, activation function, training method, etc. Subsequently, simulation models for studying fitness of the obtained models to the real systems. Interesting results were obtained, e.g. the method of the neural modelling of the system, the optimal architecture of the ANN that is a model of the system, possibilities and directions to improve a neural model of the system, etc.
EN
Aluminide coating were deposited on pure nickel and hafnium-doped nickel superalloys Mar M247, Mar M200 and CMSX 4 by means of the CVD method. All coatings consisted of two layers: an outer, comprising the β-NiAl phase and the interdiffusion one. The interdiffusion layer on pure nickel consisted of the γ′-Ni3Al phase and of the NiAl phase on superalloys. MC and M23C6 carbides besides the NiAl phase were found in the interdiffusion zones on Mar M247 and Mar M200, whereas topologically close-packed phases, such as the TCP σ-phase and the R phase were found in the interdiffusion zone on CMSX 4. Coatings on substrates containing more hafnium (Mar M247 and Mar M200) were more resistant to degradation during the cyclic oxidation. The amount of 1.5–1.8 wt.% hafnium in the substrate let to the HfO2 ‘pegs’ formation in the oxide scale during oxidation of aluminized Mar M247 and Mar M200 superalloys. The improvement of lifetime of coated CMSX 4 superalloy was obtained by platinum modification. Platinum decreased diffusion of alloying elements such as Ti and Ta from the substrate to the coating and oxide scale, stabilized the NiAl phase and delayed the NiAl → Ni3Al phase transformation.
EN
Titanium alloys based on the γ -TiAl intermetallic phase are a type of material which may replace nickel supperalloys in high temperature applications. Not enough resistance to corrosion at temperatures above 900°C remains the biggest limitation in industrial practices. The paper presents results of preliminary research into application of new type heat resistant coatings on the basis of γ -TiAl alloy. MeCrAlY and Si coatings were formed by pack cementation method. Aluminide coatings were deposited by pack cementation method and VPA. Research results have shown that except for the coating formed by VPA, coatings were characterized by high porosity and therefore would not ensure appropriate protection against oxidation. Further research will be necessary into application of the VPA method in protecting γ-TiAl titanium alloys in order to improve their heat resistance.
PL
Stopy na osnowie fazy międzymetalicznej γ-TiAl stanowią materiał, który może stanowić zamiennik nadstopów niklu w aplikacjach wysokotemperaturowych. Nadal największym ograniczeniem w ich przemysłowym zastosowaniu jest niewystarczająca odporność na utlenianie w temperaturze powyzej 900°C. W artykule przedstawiono wyniki wstępnych badań nad zastosowaniem nowych rodzajów powłok żaroodpornych na podłożu stopu γ-TiAl. Wytworzono powłoki MeCrAlY oraz Si metodą zawiesinową a także powłoki aluminidkowe metodą pack cementation oraz VPA. Wyniki badań wykazały że poza powłoką wytworzoną metodą VPA pozostałe charakteryzowały się dużą porowatością przez co nie moga zapewnić odpowiedniej ochrony przed utlenianiem. Wskazano na konieczność dalszych badań nad zastosowaniem metody VPA do ochrony stopów tytanu γ-TiAl w celu poprawy ich żaroodporności.
9
Content available Bezpieczeństwo w Afganistanie
PL
Autorzy w artykule przedstawiają wyniki swoich dociekań naukowych płynących z obserwacji funkcjonowania Polskiego Kontyngentu Wojskowego w prowincji Ghazni. Starają się dokonać podsumowania działań PKW w strefie odpowiedzialności, a także wskazują na potencjalne rozwiązania jakimi można by się posłużyć w przyszłości, podczas przygotowania PKW i SZ RP w innych misjach pokojowych.
EN
In their article the authors present the results of their investigations from the work of the Polish Military Contingent (PMC) in Ghazni. The authors attempt to sum up the work of the PMC in the zone of responsibility and show potential solutions one could use in the future during the preparation of another PMC and in the operations of the Polish Armed Forces in other peace-keeping missions.
PL
Aluminiowanie metodą CVD należy do najbardziej zaawansowanych procesów obróbki powierzchniowej łopatek turbin gazowych i silników lotniczych. Rosnące znaczenie dyfuzyjnych warstw aluminidkowych jako międzywarstw dla powłokowych barier cieplnych (TBC) determinuje prowadzenie badań nad opracowaniem warstw zapewniających najlepszą możliwą przyczepność tworzącej się warstwy tlenku aluminium w powłokach TBC z warstwami ceramicznymi osadzanymi metodami LPPS lub EB- -PVD. W badaniach jako materiał podłoża zastosowano czysty nikiel (jako materiał modelowy) oraz żarowytrzymały stop niklu MAR M200 + Hf. W artykule przedstawiono wyniki badań wpływu warunków prowadzenia wysokoaktywnego procesu CVD na mikrostrukturę i skład chemiczny powstaj ącej warstwy aluminidkowej. Proces wytwarzania prowadzono w urządzeniu Bernex BPX Pro 325S z zastosowaniem dodatkowych granul Al-Cr umieszczonych w wewnętrznym generatorze jako wysokotemperaturowe źródło aluminium. W trakcie prób zmianie podlegała temperatura oraz czas aluminiowania. Przepływ gazów, tj. chlorowodoru i wodoru dla wszystkich procesów był stały. W przeprowadzonych badaniach stwierdzono nietypowy mechanizm tworzenia się i wzrostu dyfuzyjnej warstwy aluminidkowej, który ma charakter pośredni pomiędzy modelem wysokoaktyvvnym a niskoaktywnym. Badania mikrostruktury warstwy aluminidkowej wytworzonej na podłożu czystego niklu wykazały obecność trzech charakterystycznych stref. Wydłużenie czasu oraz wzrost temperatury spowodował znaczne zwiększenie grubości dyfuzyjnej warstwy aluminidkowej. Badania mikrostruktury Warstwy aluminidkowej wytworzonej na podłożu stopu MAR M200 + Hf w tym samym czasie procesu przy zróżnicowanej temperaturze wykazały ich odmienną budowę. Mechanizm wzrostu warstwy aluminidkowej jest zależny od zawartości aluminium w źródle (granule Al-Cr).
EN
Aluminizing process by CVD method belong to the most advanced surface treatment processes of gas turbine and aircraft engine blades. Growing application of aluminides diffusion layers as bond coat for thermal barrier coatings (TBC) cause more and more researches directed on finding layer which can ensure the best possible adhesion between bond coat and top coat in the TBC system formed by LPPS or EB-PVD. In the study pure nickel and high-temperature nickel-based superalloy MAR M200 + Hf were used as initial substrate materials. In the research results of various CVD aluminizing process parameters infiuence on microstructure and chemical composition of created aluminides coatings was presented with in-depth analysis. The aluminizing process was carried out in Brenex BPX Pro 325S machine with addition ofAl-Cr granules contained in the internal generator as a high-temperature source of aluminum. During the research different temperature and time of aluminizing were applied. The flow of gases such as hydrogen chloride and pure hydrogen for all processes was constant. During the study an unusual mechanism of aluminides diffusion layer creation and growth has been observed, which has an intermediate characteristics between low-activity and high-activity models. Microstructure observation of aluminides layer formed on pure nickel substrate showed three characteristic zones. Extension of time and increase in temperature resulted in a significant increase of the diffusion layer depth. Microstructure observation of aluminides layer formed on MAR M200 + Hfwith the same process time at different temperature showed their distinct structure. Aluminides layer growth mechanism is dependent on the aluminum content in the source material (granules Al-Cr).
PL
W artykule przedstawiono wpływ długotrwałego wyżarzania dyfuzyjnych warstw aluminidkowych w próżni na ich mikrostrukturę, grubość, skład chemiczny i fazowy. W badaniach użyto próbek z żarowytrzymałego stopu niklu MAR M200 + Hf, które poddano aluminiowaniu oraz cyrkono-aluminiowaniu metodą chemicznego osadzania z fazy gazowej CVD. Wyżarzanie prowadzono w piecu próżniowym pod ciśnieniem 10–3 Pa w temperaturze 1020°C przez 12, 16 i 20 godzin. Przeprowadzone próby wyżarzania dyfuzyjnego próbek ze stopu MAR M200 + Hf z warstwą aluminidkową wykazały duże zmiany zachodzące w ich mikrostrukturze. Zachodziły one w następującej kolejności: – po 12 h wyżarzania zaobserwowano początek koagulacji wydzieleń w strefie dyfuzyjnej, – po 16 h doszło do dalszej koagulacji wydzieleń w strefie dyfuzyjnej oraz niewielkiego zmniejszenia stężenia aluminium w powłoce (o ok. 1%); stwierdzono niewielki wzrost grubości całkowitej warstwy, – po 20 h wyżarzania zaszły duże zmiany w mikrostrukturze warstwy; zubożenie obszaru przypowierzchniowego w aluminium do ok. 24% at., poniżej zawartość aluminium rosła do ok 30%; poszerzenie strefy dyfuzyjnej, która dominuje w budowie warstwy, rozpuszczenie niektórych wydzieleń; zawartość Al w pobliżu podłoża – ok 24% at. Przeprowadzone badania wykazały, że w pierwszej kolejności przemianie podlega strefa dyfuzyjna, a następnie dochodzi do zmian w strefie zewnętrznej zbudowanej początkowo z fazy β-NiAl, w tym utworzenia fazy Ni3Al.
EN
The paper presents the influence of long-term annealing on simple and Zr-modified aluminide coatings. The base material was MAR M-200 nickel superalloy. The aluminide coating was deposited in low-activity chemical vapour deposition process. The samples (14 mm diameter) were annealed at 1020°C in vacuum for 12, 16 and 20 hours respectively. The tests of diffusion annealing showed significant changes in microstructure of the samples. The order of changes was as follows: – after the 12-hour-long annealing process initial coagulation of precipitates in the diffusion zone was observed, – after the 16-hour-long annealing process there was observed further coagulation of precipitates and a small decrease in aluminum concentration in the coating (by approx. 1%). A small increase in thickness of the coating was also noted, – after the 20-hour-long annealing process extensive changes in microstructure of the coating were observed. The increasing of external zone thickness was observed. The presence of grains with lower Al amount was detected. It suggest the presence of Ni3Al phase in the coating. The very low amount of Zr had not influence on changes in modified aluminide coating during annealing.
12
Content available remote Nowe możliwości osadzania warstw ceramicznych poprzez zastosowanie metody PS-PVD
PL
W artykule przedstawiono aktualny stan wiedzy w zakresie procesu natryskiwania plazmowego pod obniżonym ciśnieniem z odparowaniem proszku PS-PVD. Metoda ta zapewnia uzyskiwanie warstwy ceramicznej powłokowej bariery cieplnej o budowie kolumnowej, charakterystycznej dla otrzymywanych w procesie EB-PVD. Przedstawione zostały wyniki pierwszych prób osadzania warstw w tym procesie realizowanych w Laboratorium Badań Materiałów dla Przemysłu Lotniczego. Wykazano możliwość wytworzenia warstw na warstwach aluminidkowych wytworzonych metodą kontaktowo-gazową oraz gazową (VPA). Uzyskane wyniki wskazują na zasadność kontynuowania badań.
EN
The current condition of knowledge was introduced in the article in the range of the process of plasma spraying under the lowered pressure with vaporization of the powder PS-PVD. This method assures getting the ceramic layer of the thermal barrier coating about the columnar, characteristic building for received in the process EB-PVD. The results of first tests of sediment layers in this process realized in R&D Laboratory for Aerospace Materials were introduced. The possibility of producing layers on layers aluminium coating produced the method contact - gas and gas (VPA) was showed. Got results show on the legitimacy of continuing investigations.
13
Content available remote Charakterystyka ceramicznych materiałów stosowanych do natryskiwania plazmowego
PL
W artykule przedstawiono podstawowe właściwości materiałów stosowanych do natryskiwania powłokowych barier cieplnych w warunkach obniżonego ciśnienia. Analizie poddano proszki stosowane przez firmę Sulzer-Metco do procesów LPPS-Thin Film. Przedstawiono charakterystykę wybranych proszków stosowanych na międzywarstwy oraz zewnętrzną warstwę ceramiczną. Przedstawiono analizę proszków na bazie tlenku cyrkonu stabilizowanych tlenkami itru, magnezu oraz wapnia.
EN
The authors described in this article the basic properties of materials used for spray process of thermal barrier coatings under low pressure. Powders used by Sulzer-Metco company for LPPS-Thin Film processes were analysed. The characteristic of selected powders applied for bond-coats and outer ceramic layer was introduced. The authors presented the analysis of powders based on zirconium oxide stabilized by yttrium oxide, magnesium and calcium.
PL
Niniejsza praca dotyczy badań na temat możliwości wytworzenia materiałów spiekanych w procesie recyklingu form ceramicznych użytych do wykonania precyzyjnych odlewów elementów silników lotniczych. Na podstawie przeprowadzonych badań proszków przed i po procesie mielenia oraz prób ich prasowania i spiekania stwierdzono, że możliwy jest proces recyklingu zużytych form ceramicznych, stosowanych na odlewy precyzyjne elementów silników lotniczych. Do prasowania stosowano proszki ze zmielonych form bez dodatków oraz z dodatkami modyfikatorów. W obu przypadkach uzyskano dobre rezultaty w procesie prasowania i spiekania. Powierzchnie wyprasek i spieczonych próbek były gładkie i nie ulegały rozwarstwieniu, a także nie wykruszały się.
EN
The present work relates to investigations of the possibility to produce sintered materials in the recycling process of ceramic moulds coming from precise casts for air engines elements. On the basis of conducted investigations of powders before and after milling, and tests of their pressing and sintering it has been affirmed that the recycling process of the spent ceramic moulds is possible. It was applied to presses the powders derived from the ground moulds with and with no additions of modifiers were studied. Both types of the powders gave good results when processed by pressing and sintering. Surfaces of compacts and sintered bodies were smooth, and did not undergo foliation, and also they did not crumble.
15
Content available remote Thermophysical properties of selected powders for thermal barrier coatings
EN
Purpose: Plasma-sprayed thermal barrier coatings often have the problems of spallation and cracking in service owing to their poor bond strength and high residual stresses. Functionally graded thermal barrier coatings with a gradual compositional variation from heat resistant ceramics to fracture-resistant metals are proposed to mitigate these problems. Design/methodology/approach: The results of measurements of thermal diffusivity by using one of the most modern experimental sets LFA 427 (Laser Flash Apparatus) produced by Netzsch Company. In order to measure the specific heat cp(T) and density p(T), two methods of termogravimetry analysis were used STA 449 Jupiter F3 Netzsch Company and gas displacement density analyzer AccuPyc II 1340 Micromeritics Company. Research limitations/implications: This paper presents the results of measurements of thermal diffusivity coefficient as a function of temperature for Sulzer powders, AMDRY 997, AMDRY 365C, METCO 45C NS, METCO 202 NS, METCO 204 NS. Practical implications: Optimal technical and technological parameters of powders for thermal barrier coatings have been selected. Originality/value: The presented method undoubtedly develops new possibilities for thermal barrier coatings.
16
Content available remote Thermal stability of protective coatings produced on nickel based superalloy
EN
Purpose: In this paper the results of high temperature cyclic oxidation tests of the protective diffusion coatings were presented. One of the main purposes of this work was to produce three different types of protective coatings by three different methods, i.e. slurry method, vapour phase aluminizing (VPA) and chemical vapour deposition (CVD), applied on nickel based Rene 80 superalloy substrate. Design/methodology/approach: The high temperature cyclic oxidation tests were carried out in 23h cycles at constant temperature 1100°C using Carbolite CWF 1300 chamber furnace. The samples were removed outside and were weighted after each cycle. The microstructure investigations of all kinds of the coatings were conducted by the use of light microscope (Nikon Epiphot 300) and a scanning electron microscope (Hitachi S-3400N). In the analysis influence of each method have been taken into consideration, i.e. especially influence of the kind of process on microstructure, coating thickness, chemical composition, first of all aluminium content (in outer β-NiAl layer so-called additive layer, diffusion layer and substrate). For the chemical composition examination x-ray energy dispersive (EDS) method was applied using Thermo equipment. Findings: It was found that the best high cyclic oxidation resistance of coating was obtained using CVD method (the maximal increase of samples weight after 28th cycle was observed, whereas in case of the slurry sample after 3rd and VPA after 5th). Research limitations/implications: The research results will be used in the future in order to increase coating thickness, aluminium content and to produce Pt, Pd, Zr, Hf and Si modified aluminide coatings. Practical implications: The CVD method will be used to coat internal passages of turbine blades, for example to produce modified aluminide bond coats on single crystal nickel based superalloys. Originality/value: Chemical vapour deposition is an unique method which is a “pure method” and allows to coat hardly accessible locations/areas.
17
Content available remote Recycling process of casting molds applying to precision castings
EN
Purpose: The present work relates to investigations about the possibility of recycling and producing sinters from ceramic molds. These molds are applied for producing precise single crystal casts of nickel based superalloys to elements witch are applied to the hot section of aircraft jet engines. Design/methodology/approach: The processes of milling were carried out using the vibratory mill Herzog HSM 100H and the planetary grinder Pulverisette 7 - Fritsch Company. The measurements of all kinds of powders were conducted by using of the Kamika IPS U Analyzer and Malvern Nanosizer-ZS. To the purpose of analysis of the chemical composition an X-ray microanalysis technique was applied with the dispersion of the energy (EDS) using of Thermo and Noran equipment. Findings: On the basis of examinations carried out on the powders before and after processes of milling and after processes of pressing and sintering of powders, it is possible to state that technological processes of reuse and further applying of used molds are possible. Processes of pressing were conducted applying different amounts of powders. Powders were pressed both without the addition as well as with the addition of modifiers which were added to basic powder in appropriate amounts. It was found that processes of pressing and sintering in both cases showed good results. Surfaces of pressed and sintered tablets were smooth and not-delaminated as well as did not shell. Research limitations/implications: Results will be used for future researches among others concerning the research on mechanical and thermal properties. Practical implications: Waste products and their reuse, recycling and especially consolidation of dangerous and hazardous compounds including of ceramic materials from foundry industry, will have an important place in the future on account of problems with their recycling and the storage. Originality/value: Researches on new possibilities of the application and properties of waste materials.
18
Content available remote Heat treatment and CVD aluminizing of Ni-base René 80 superalloy
EN
Purpose: This work presents the results of microstructure investigations which were carried out on Ni-base Rene 80 polycrystalline superalloy. Design/methodology/approach: Polycrystalline cast rods have been used in the studies. The heat treatment processes were conducted in ALD High Temperature Vacuum Furnace at 1204°C for 2 h, in Ar atmosphere followed by cooling to room temperature. The aluminizing processes were conducted by use of CVD method on as cast samples and after homogenizing-solution annealing. The diffusion low activity aluminide coatings have been produced using the CVD IonBond BPXPR0325S apparatus at various temperatures, for 4 h and applying different values of: flow rate of HCl through the outer AlCl3 generator and pressure in main retort in H2 atmosphere. The microstructure investigations were conducted using scanning electron microscope. To the purpose of analysis of the chemical composition an X-ray microanalysis technique was applied with the dispersion of the energy (EDS) using of Thermo and Noran equipment. Findings: It was found that samples without heat treatment had the typical cast microstructure with many areas of the y-y’ eutectic, after heat treatment process the microstructure was homogenized, i.e. the eutectic y-y’ has been dissolved, MC-type carbides were precipitated on the grain boundaries and the chemical composition was balanced. It was found also that after homogenizing heat treatment the samples had the thicker coating and had more homogenous additive and diffusion layer than the samples with as-cast microstructure. Research limitations/implications: Results will be used for further steps which will consist of CVD process and other different heat treatment. Practical implications: This CVD method will be used in the future for the production of modified aluminide bond coats on single crystal Ni-base superalloys underlying the ceramic EB-PVD or LPPS top coatings. Originality/value: In the future the production of chemical vapor deposited platinum (or Pd, Zr, Hf) aluminide diffusion coatings on nickel base superalloy substrate are planned.
EN
Purpose: The comparison of three deposition of coatings method. Design/methodology/approach: The diffusion aluminide coatings were deposited using the pack cementation, out of pack and CVD method. Findings: The authors present in the article the results on influence of the method of manufacturing the aluminide coatings on their microstructure and oxidation resistance. Research limitations/implications: The thickness analysis and the chemical composition analysis with a use of light microscopy, scanning electron microscopy and EDS analysis were performed. Practical implications: This process can be used in aerospace industry to form oxidation resistant coatings. Originality/value: It has been proven, that the coating obtained with CVD method, despite its small thickness, was characterized by the best cyclic oxidation resistance.
EN
Purpose: The preliminary results of research on forming the aluminide coatings using CVD method were presented in the article. Design/methodology/approach: The coatings were obtained in low activity process on the surface of Rene 80 superalloy. The microstructure analysis and chemical composition analysis were performed applying different values of aluminizing process parameters. Findings: The authors present in the article the results of oxidation resistance analysis of aluminide coatings which were obtained on the surface of Rene 80 superalloy using various techniques. Research limitations/implications: The research results revealed the possibility of obtaining coatings by low activity aluminizing. Practical implications: This process can be used in aerospace industry to form oxidation resistant coatings. Originality/value: It was shown that the coating created during the CVD process was characterized by a good oxidation resistance at the temperature of 1100°C.
first rewind previous Strona / 2 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.