Wyniki wyszukiwania - Biblioteka Nauki

1

Investigation of thermal processes during test operation of ingot mould with composite surface layer

100%

Szajnar J. , Wróbel P. , Wróbel T.

Archives of Foundry Engineering

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2008

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tom Vol. 8, iss. 3s

163--166

EN

The paper presents a method of usable properties of surface layers improvement of grey cast iron EN-GJL-200 ingot mould, by put directly in founding process a composite surface layer on the basis of corundum Al2O3 and quartz sand SiO2. Technology of composite surface layer guarantee mainly increase in hardness and abrasive wear resistance of cast steel and cast iron castings on machine elements. This technology can be competition for generally applied welding technology (surfacing by welding and thermal spraying). The results of studies show, that is positive influence of composite surface layer with ceramic particles on increase in life of cast iron ingot moulds.

2

Characteristics of microstructure in composite surface layers

100%

Dudek A. , Nitkiewicz Z.

Archives of Foundry Engineering

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2008

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tom Vol. 8, iss. 1 spec.

75--78

EN

Heat spraying consists in manufacturing of a metal, cermetallic or ceramic coating on the surface of any product by means of special-purpose blowpipe for melting and spraying of the applied materials. The sprayed layers are typically characterized by low adhesion to the surface and low cohesion, which limits opportunities of wide application. Additional processing is performed in order to rebuilt the created coatings, by e.g. surface treatment by application of concentrated energy sources [1-16]. The purpose of this work was a cognitive analysis of structural effects which occur in the alloyed surface layer melted with three various types of heat sources - laser, plasma and TIG welding method. Surfaces of samples were previously covered with l00μm TiO2 ceramic layer. The investigations, carried out in order to correlate structural effects in the created surface layer, revealed differences between beams used during heat treatment, in consideration of both methodology and structural results of the process.

3

Multi-layers castings

84%

Szajnar J. , Wróbel P. , Wróbel T.

Archives of Foundry Engineering

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2010

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tom Vol. 10, iss. 1

181-186

EN

In paper is presented the possibility of making of multi-layers cast steel castings in result of connection of casting and welding coating technologies. First layer was composite surface layer on the basis of Fe-Cr-C alloy, which was put directly in founding process of cast carbon steel 200-450 with use of preparation of mould cavity method. Second layer were padding welds, which were put with use of TIG - Tungsten Inert Gas surfacing by welding technology with filler on Ni matrix, Ni and Co matrix with wolfram carbides WC and on the basis on Fe-Cr-C alloy, which has the same chemical composition with alloy, which was used for making of composite surface layer. Usability for industrial applications of surface layers of castings were estimated by criterion of hardness and abrasive wear resistance of type metal-mineral.

4

Program do obliczania grubości powierzchniowych warstw kompozytowych na odlewach staliwnych

84%

Baron C. , Szajnar J.

Kompozyty

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2008

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tom R. 8, nr 1

15-21

PL

Proces tworzenia się kompozytowych warstw powierzchniowych jest złożony i zależy od wielu czynników technologicznych i materiałowych. Stąd też nie można jednoznacznie określić, jaka będzie jej grubość w danym miejscu odlewu. Skłania to do poszukiwania grubości warstwy kompozytowej jako pewnej zmiennej losowej. W pracy przyjęto założenie, aby poszukiwaną zmienną losową modelować prostym procesem zgłoszeń. Zbudowano algorytm w oparciu o podany proces stochastyczny, który następnie został wykorzystany do budowy programu komputerowego Preforma 1.1, służącego do obliczania wartości grubości warstwy kompozytowej. Głównym celem niniejszej pracy było wykazanie skuteczności metody opartej na rachunku prawdopodobieństwa z uwzględnieniem wyników uzyskanych empirycznie. W celu udowodnienia skuteczności metody stochastycznej wyznaczania grubości kompozytu porównano realne grubości kompozytu uzyskanego na drodze doświadczenia z grubością kompozytu otrzymanego w oparciu o program symulacyjny NovaFlow&Solid i Preforma 1.1. Wyznaczone wartości grubości warstwy kompozytowej przy zastosowaniu autorskiego programu Preforma 1.1 okazały się porównywalne z wartościami otrzymanymi na staliwnych odlewach doświadczalnych, co świadczy o poprawności metody. Należy podkreślić, iż zaletą metody jest jej prostota w użyciu. Metoda ta pozwala ominąć opis skomplikowanych zjawisk wynikających z procesów dyfuzyjnych, uzależniając wyznaczanie grubości warstwy kompozytowej tylko od temperatury zalewania i czasów (ts) przebywania preformy powyżej Ts.

EN

The production of cast with composite surface layer is not complicated for technological reasons. However, the process of forming these layers is complex and depends on many technological and material factors. Because of great amount of factors, which influence the thickness, it is possible to use the theory of probability to calculate the thickness of composite layer in particular part of the cast. The composite layer can be 1 mm thick or 2 mm thick and so on. So we can deal with the composite layer formation process as with the process of forming some partial layers. It is assumed that these layers appears in turn, of course - with a certain probability. It means, that the composite layer is formed by a random variable. Its thickness is a the expected value of this random variable. It is assumed, that the layers appears in turn and in this way form whole composite layer, so we can treat this process as a simply stochastic process of entries. The preform temperature (concretely the preform time of staying in the temperature between Ts - Tl) was assumed as a basic factor which influences the thickness of composite layer. The algorithm (to determine the thickness of composite layer with the use of stochastic process) was worked out and used to build the program Preforma 1.1. The aim of researches was to prove the correctness of the method based on the calculus of probability thanks to the results of real casts. To prove the correctness of the stochastic method of determination the thickness of composite layer, the real thickness of composite formed during the real experiment were compared with the thickness of composite obtained from the simulation and program Preforma 1.1. In order to prove the correspondence between the preform times of staying in the temperature between Ts - Tl obtained from real experiment and simulation, the comparative analysis should be done in the same points of measurement. The goodness was obtained and allowed to use the results of simulation and real cast to build and check the mathematical model and computer program Preforma 1.1. The main conclusion is that the determined thickness of composite layer, with the use of program Preforma 1.1, are compatible with the thickness of composite layers measured during the experiment so this program is a useful tool to project the thickness of composite layers.

5

Wpływ substancji smarowej na właściwościkompozytowych przeciwzużyciowych warstw wierzchnich

67%

Madej M. , Ozimina D. , Lodzińska M. , Piekoszewski W.

Zeszyty Naukowe Politechniki Świętokrzyskiej. Mechanika

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2005

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tom Z. 83

47-55

PL

W artykule przedstawiono metodę wytwarzania przeciwzużyciowych warstw powierzchniowych o osnowie metalowej z wtrąceniami drobnodyspersyjnej fazy ceramicznej. Warstwy kompozytowe Ni-P-Al2O3 osadzano sposobem bezprądowym na stali 45. Badania właściwości tribologicznych otrzymanych warstw prowadzono w warunkach tarcia technicznie suchego, jak również podczas tarcia granicznego w modelowej substancji smarowej zawierającej dodatek przeciwzużyciowy ZDDP. Artykuł przedstawia wyniki badań prowadzonych w skali makro - na aparacie T-01M, a także mikro/nanoskali przy użyciu Mikroskopu Sił Atomowych - AFM.

EN

The article discusses methods for the deposition of antiwear, composite coatings with a metallic matrix and the ceramic microdispersive Al2O3 phase. The composite Ni-P-Al2O3 superimposed on carbon C45 steel elements using the electroless plating technique. The research on tribological properties of the obtained layers werw carried out at technically dry friction conditions and also during boundary friction for model lubricant containing antiwear additive - ZDDP. The paper presents the results of tribological tests, it also analyses the effects of tribochemical interactions in the macroscale, using in a pin-on-disc system device, in the micro/nanoscale - performed with the use of Atomic Force Microscopy - AFM.