Wyniki wyszukiwania - Biblioteka Nauki

1

Mikrostruktura warstw aluminidkowych modyfikowanych proszkiem NiCrAlY uzyskiwanych metodą zawiesinową na stopie Re 80

100%

Góral M. , Filip R.

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tom Vol. 32, nr 4

425-428

PL

Metoda zawiesinowa stanowi jedną z najstarszych metod wytwarzania powłok aluminidkowych na nadstopach niklu oraz stopach żelaza i tytanu. Charakteryzuje się stosunkowo niskimi kosztami wytwarzania oraz niezbędnych urządzeń. Umożliwia także prostą modyfikację składu chemicznego przez dodawanie proszków o zróżnicowanym składzie chemicznym. W artykule przedstawiono możliwość modyfikowania składu chemicznego zawiesiny typu Al-Si stosowanej do wytwarzania powłok aluminidkowych na nadstopach niklu przez wprowadzenie proszku typu MeCrAlY w stosunku (do proszku Al-Si) 1:1 i 2:1. Przeprowadzono także próbę nanoszenia samego proszku typu MeCrAlY z wykorzystaniem frakcji ciekłej zawiesiny typu Al-Si. Zawiesinę nanoszono przez zanurzanie, a po osuszeniu wyżarzano w temperaturze 950°C przez 2 godziny. Grubość uzyskanych warstw mieściła się w zakresie 30÷65 um.

EN

The slurry method is one of the oldest methods of aluminide coating deposition on the nickel superalloy as well as ferrum and titanium alloys. It is characterized by relatively low costs of production and of equipment. It enables simple modification of chemical composition through addition of powders with various chemical composition. In the article the possibility of chemical composition modification of the Al-Si slurry used for aluminide coating deposition on the basis of nickel superalloys through introduction of MeCrAlY powder (in 1:1 or 2:1 ratio with Al-Si powder) has been introduced. There was also a research conducted on introduction of MeCrAlY powder with a use of fraction of liquid Al-Si slurry. The slurry was deposited through immersion and annealed (after drying) in the temperature of 950°C for two hours. The thickness of obtained coatings was in the range of 30÷65 um.

2

Microstructural evaluation of CMSX-4 superalloy single crystal castings of various geometry

84%

Szular A. , Onyszko A. , Motyka M.

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tom Vol. 31, nr 3

618-621

EN

The effect of single crystal growth rate and casting geometry on CMSX-4 nickel base superalloy microstructure was determined in the paper. Single crystal castings in the form of round rods and turbine blades for aircraft engine were produced in directional crystallization process (by Bridgman method) at withdrawal rate (vw) of 4 and 5 mm/min. Metallographic examination and quantitative evaluation of dendritic microstructure in obtained castings were carried out.

PL

W pracy podjęto próbę określenia wpływu prędkości monokrystalizacji i geometrii odlewów na mikrostrukturę nadstopu niklu CMSX-4. Odlewy monokrystaliczne w formie okrągłego pręta i łopatki turbiny silnika lotniczego otrzymano w procesie krystalizacji kierunkowej (metodą Bridgmana) z prędkością wyciągania vw = 4 i 5 mm/min. Przeprowadzono badania metalograficzne oraz ilościową ocenę mikrostruktury dendrytycznej otrzymanych odlewow.

3

Technologia mikronapawania i mikroprzetapiania plazmowego nadstopu na bazie niklu Inconel 713C

84%

Klimpel A. , Kik T. , Krasnowski K.

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2008

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tom R. 52, nr 4

47-50

PL

Przedstawiono wyniki badań wpływu parametrów technologicznych zrobotyzowanego procesu mikronapawania i mikroprzetapiania plazmowego wad modelowych punktowych i liniowych w nadstopie niklu Inconel 713C na jakość uzyskanych mikronapoin i mikroprzetopień. W pracy przedstawiono także zalecane warunki technologiczne procesu mikronapawania i mikroprzetapiania plazmowego typowych wad modelowych próbek z nadstopu Inconel 713C.

EN

It has been presented the results of investigations into the influence of parameters of robotized micro plasma surfacing and micro plasma remelting of linear and spot model flaws in superalloy Inconel 713C on quality of micro remelts and micro overlay welds. There are also presented the recommended technological conditions of micro plasma surfacing and micro plasma remelting for typical model flaws in superalloy Inconel 713C.

4

Surface modification, microstructure and mechanical properties of investment cast superalloy

84%

Zielińska M. , Kubiak K. , Sieniawski J.

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2009

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tom Vol. 35, nr 1

55-62

EN

Purpose: The aim of this work is to determine physical and chemical properties of cobalt aluminate (CoAl2O4) modifiers produced by different companies and the influence of different types of modifiers on the grain size, the microstructure and mechanical properties of high temperature creep resisting superalloy René 77. Design/methodology/approach: The first stage of the research work took over the investigations of physical and chemical properties of cobalt aluminate manufactured by three different companies: Remet, Mason Color and Permedia Lublin. There were determined the grain size distribution of cobalt aluminate powder, the average diameter of the powder particles, phase composition, cobalt contamination. In the next step, the ceramic moulds were made with different kind of cobalt aluminate (Mason Color, Remet, Permedia Lublin) and its concentration (0.5%) in the primary slurry. The samples of stepped and cylindrical shape were poured in the ceramic moulds prepared earlier. The average grain size of the . phase, was determined on the stepped samples. The microstructure investigations let to examine the influence of the surface modification on the morphology of . ‘ - phase and carbides precipitations. Samples were turned from cylindrical castings for mechanical properties investigations: creep tests. Findings: Modification of the face coat of ceramic mould results in the reduction of the grains size of . matrix and disintegration of carbide precipitates. It results in the improvement of mechanical properties of the alloy. On the grounds of the obtained results, it was found that the type of used modifier influenced the grain size of the alloy and its mechanical properties. Research limitations/implications: The established physical and chemical properties of modifier let to get better control of grain size of the castings and their quality what will result in decrease of defective products. Originality/value: It was proved that the effectiveness of cobalt aluminate modifier as an inoculant depends not only on its concentration in ceramic slurry but on its chemical composition. The researches allowed to find the optimal concentration of Co in CoAl2O4 to produce casting elements made from superalloy René 77.

5

Effect of modification and cooling rate on the microstructure of IN-713C alloy

84%

Binczyk F. , Śleziona J. , Kościelna A.

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2009

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tom Vol. 9, iss. 4

5-8

EN

The results of investigations of the effect of modification and cooling rate on the microstructure of castings made from IN-713C nickel superalloy were described. As an inoculant, cobalt aluminate CoAl2O4 in composition with aluminium powder and colloidal silica was used. Changes in the cooling rate were obtained by the use of cast stepped test piece with steps of 6, 11 and 17 mm thickness. The phase and chemical composition of microstructural constituents, i.e. of \gamma phase, \gamma' phase and eutectic carbide precipitates, was evaluated. A significant effect of the cooling rate and modification treatment on the stereological parameters of carbide precipitates was confirmed. Problems in evaluation of the chemical composition of these precipitates in the case of a high degree of the structure refinement were indicated.

6

Macro- and microhardness of IN-713C nickel superalloy constituents

84%

Binczyk F. , Śleziona J.

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2009

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tom Vol. 9, iss. 4

9-12

EN

The results of investigations of the effect of modification and cooling rate on the macrohardness of castings and microhardness of phase constituents in IN-713C nickel superalloy were described. As an inoculant, cobalt aluminate CoAl2O4 in composition with aluminium powder and colloidal silica was used. Changes in the cooling rate were obtained using a cast stepped test piece with steps of 6, 11 and 17 mm thickness. Macrohardness of the cast test piece steps was measured by Brinell technique, while Vickers method was used to measure the microhardness of \gamma and \gamma' phases present in the alloy matrix, as well as the hardness of eutectic carbide precipitates. A significant effect of the cooling rate and modification treatment on the results of the measurements was stated, and difficulties in performing correctly the microhardness measurements due to the precipitates dimensions, especially after the modification treatment, were highlighted.

7

Microstructure and mechanical properties of high temperature creep resisting superalloy Rene 77 modified CoAl2O4

84%

Zielińska M. , Sieniawski J. , Poręba M.

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2007

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tom Vol. 28, nr 10

629-632

EN

Purpose: Nickel based superalloys are widely used for turbine and stator blades of compressor in aero-engines. The objective of this work is to determine the influence of the inoculant's content (cobalt aluminate) in the surface layer of the ceramic mould on the microstructure and mechanical properties of high temperature creep resisting superalloy Rene 77. Design/methodology/approach: Experimentally investigated castings have been made of commercially produced nickel superalloy Rene 77. Stepped and cylindrical samples have been casted for: microstructure and mechanical examinations. During preparation of ceramic face mould, it has been added the suitably inoculant's content of: 0,5, 10% mass in zirconium flour. The microstructure analysis has been made by the use of light microscopy. Verification of the influence of CoAl2O4 on the mechanical properties of castings has been investigated on the basis of results obtained form tensile and creep tests. Findings: Modification of the face coat of ceramic mould results in the reduction of the grains size of ϒ matrix and disintegration of carbide precipitates. It results in the improvement of mechanical properties of the alloy. On the grounds of the obtained results, it was found that the sufficient incoulant concentration in the surface layer of ceramic mould is 5%mass. Research limitations/implications: As the cost of material and process are very high, the castings were made with only three different contents of cobalt aluminate in the surface layer of ceramic mould. Practical implications: Originality/value: It was revealed, that inoculant content have a significant impact on the microstructure of superalloy Rene 77 depending on the casting section thickness. It was proved that modification of surface layer of ceramic mould has a positive effect on the mechanical properties of superalloy. The researches allowed to find the optimal concentration of CoAl2O4 in ceramic mould to produce casting elements made from superalloy Rene 77.

8

Pojemność cieplna a żaroodporność odlewniczych nadstopów niklu na łopatki turbin

84%

Przeliorz R. , Swadźba L. , Góral M.

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2008

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tom nr 4-5

171-173

PL

Badano pojemność cieplną oraz odporność na utlenianie odlewniczych nadstopów niklu. Pomiary pojemności cieplnej właściwej przeprowadzono metodą różnicowej kalorymetrii skaningowej -DSC. Stwierdzono, że w zakresie temperatury 300-500oC i 700-900oC pojemność cieplna jest stała lub wzrasta w niewielkim stopniu. W temperaturze 500-700oC oraz powyżej temperatury 900oC na krzywej cp występuje anomalia. Zjawisko polega na wzroście pojemności cieplnej. Badania żaroodporności przeprowadzono metodą cyklicznego utleniania. W temperaturze 1100oC obserwowano ciągły ubytek masy. Najsilniej zgorzelina odpada na stopie IN 738.

EN

The heat capacity and the oxidation resistance of the casting nickel alloys has been investigated. The specific heat capacity has been measured by means of differential scanning calorimetry (DSC). It has been confirmed that at temperatures ranging from 300 to 500oC and from 700 to 900oC the heat capacity is either constant or shows minor increase. At temperatures ranging from 500 to 700oC and over 900oC an anomaly in the cp curve appears. The phenomenon consists in the increase in the heat capacity. The heat resistance has been assessed by cyclic oxidation testing. At 1100oC a constant mass loss has been observed. The strongest fl aking of the scale has been detected in the case of IN 738 alloy.

9

Effect of modification and cooling rate on the macrostructure of IN-713C alloy

67%

Binczyk F. , Śleziona J. , Kościelna A.

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2009

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tom Vol. 9, iss. 3

13-16

EN

The results of investigations of the effect of modification and cooling rate on the macrostructure of castings made from IN-713C nickel superalloy were described. As a modifier, cobalt aluminate CoAl2O4 in composition with aluminium powder and colloidal silica was used. Changes in the cooling rate were obtained by the use of a stepped test piece with the steps of 6, 11, 17 and 23 mm thickness. As a criterion for the evaluation of casting macrostructure, the stereological parameters, like grain count, relative surface area, shape factor, and indeces of the grain size and shape homogeneity, were applied. The modification treatment was observed to change the grain type from columnar to equiaxial. The stereological parameters of the equiaxial grains depended to a great extent on the cooling rate of the individual elements of a cast stepped test piece.

10

Phase transformations and microstructure of IN-713C nickel superalloy

67%

Binczyk F. , Śleziona J.

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2009

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tom Vol. 9, iss. 2

109-112

EN

The study presents the results of investigations of phase transformations taking place during melting and solidification and of microstructural examinations carried out on the family of IN 713C nickel superalloys. Examinations were carried out by the method of thermal analysis (ATD) and differential scanning calorimetry (DSC). It has been concluded that the method of thermal analysis (ATD) enables more precise assessment of the precipitation of the primary phases of a low value of the solidification enthalpy. The advantage of DSC is the possibility of determination of the value of the heat (enthalpy) of phase transformations during alloy melting and solidification. The measured parameters of Tlik and Tsol are comparable for both methods. Microstructural examinations have confirmed the phenomena accompanying phase transformations, i.e. the precipitation of primary carbides, the solidification of [...] phase matrix and carbide eutectic, and the formation of [...] phase in solid state.

11

Macrostructure of IN-713C superalloy after volume modification

67%

Binczyk F. , Śleziona J.

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2009

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tom Vol. 9, iss. 2

105-108

EN

The study discusses the results of the preliminary investigations of the process of volume modification of nickel and cobalt superalloys. The investigations were carried out on an IN-713C alloy. As an inoculant, cobalt aluminate CoAl2O4 in composition with aluminium powder and zircon flour was used. Experiments included the use of inoculant-coated filters and inoculant placed on and between the filters. As a criterion for evaluation of the modification effect, the macrostructure produced in a stepped test casting was used. It has been concluded that the modification effect depends, first of all, on the pouring temperature and on the time of contact between the liquid alloy and inoculant. Compared with the non-modified alloy, which has columnar grains in its structure, the refining treatment gave very fine and equiaxial grains. The higher was the cooling rate (or the smaller was the thickness of the step), the finer were the equiaxial grains.

12

Calorimetric examination of mixtures for modification of nickel and cobalt superalloys

67%

Binczyk F. , Śleziona J. , Przeliorz R.

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2009

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tom Vol. 9, iss. 2

97-100

EN

The study presents the results of thermodynamic calculations and calorimetric examination of thermal reactions taking place at high temperatures between the nanoparticle inoculants and metallic constituents of nickel and cobalt superalloys. The calculations and measurements were made for different compositions, containing cobalt aluminate CoAl2O4, cobalt oxide CoO*Co2O3, zircon flour ZrSi2O4, powdered and metallic Al, powdered Ti, and IN-713C alloy. The obtained results have indicated the possibility of using certain mixtures as potential inoculating additives for the volume modification of nickel and cobalt superalloys. A characteristic feature of these alloys is the formation of a detrimental structure containing very large columnar crystal, present even in castings of a very high solidification rate. It has been proved that the inoculant most effective in the formation of the structure of equiaxial grains is the inoculant based on cobalt aluminate, colloidal silica and powdered aluminium.

13

Modification of macrostructure of nickel superalloys with cobalt nanoparticles

67%

Binczyk F. , Śleziona J. , Gradoń P.

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2011

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tom R. 11, nr 1

49-54

EN

The paper presents the results of studies on the effect of combined surface and bulk modifications on the macrostructure of castings made from remelted, post-production IN-713C, IN-100 and MAR-247 waste alloys. Surface modification was carried out by applying onto the wax pattern surface, a coating containing zirconium silicate and cobalt aluminate. Bulk modification was carried out when the cast liquid alloy was passed through a special ceramic filter containing, among others, cobalt aluminate. The nanoparticles of cobalt, acting as crystallisation nuclei, are the product of a modifier reaction (CoAl2O4 inoculant) with the chemically active constituents of the nickel alloys and with the additional filter components in the form of Al and Ti powders. The filters were placed in the mould pouring basin. The beneficial effect of combined modification on the macrostructure (equiaxial crystals) and mechanical properties was stated. The effect of the active constituents present in the nickel alloys and in the filter material was confirmed. A particularly strong refining effect on the macrostructure of equiaxial crystals was obtained in the MAR-247 alloy, which contained the strongest chemically active additives of Hf, Ta and Nb. A hypothetical model of the surface and bulk modification was developed. A strong influence of the alloy pouring temperature on the modification effect was reported. Modification was most effective when the pouring temperature did not exceed 1440°C.

PL

Zamieszczono wyniki badań wpływu łącznego modyfikowania powierzchniowego i objętościowego na makrostrukturę odlewów wykonanych po przetopie odpadów poprodukcyjnych ze stopów IN-713C, IN-100 i MAR-247. Modyfikację powierzchniową zrealizowano poprzez naniesienie na model woskowy powłoki zawierającej krzemian cyrkonu i glinian kobaltu. Modyfikację objętościową zrealizowano podczas odlewania ciekłego stopu przez specjalne filtry ceramiczne, zawierające między innymi glinian kobaltu. Nanocząstki kobaltu, pełniące rolę zarodków krystalizacji, są produktem reakcji modyfikatora (inoculant CoAl2O4) z aktywnymi chemicznie składnikami stopów niklu oraz dodatkowymi składnikami filtrów w postaci proszków Al i Ti. Filtry umieszczono w zbiorniku wlewowym formy. Stwierdzono korzystny wpływ łączonej modyfikacji na makrostrukturę (kryształy równoosiowe) i właściwości mechaniczne. Potwierdzono oddziaływanie aktywnych składników obecnych w stopach niklu i materiale filtrów. Szczególnie silny efekt rozdrobnienia makrostruktury kryształów równoosiowych uzyskano dla stopu MAR-247, który zawiera najbardziej aktywne chemicznie dodatki Hf, Ta i Nb. Opracowano hipotetyczny model modyfikacji powierzchniowej i objętościowej. Stwierdzono istotny wpływ temperatury odlewania stopu na efekt modyfikowania. Efekt modyfikowania jest szczególnie widoczny przy temperaturze odlewania poniżej 1440°C.