Wyniki wyszukiwania - Biblioteka Nauki

1

Application of low-temperature low-pressure hydrogen plasma: treatment of artificially prepared corrosion layers

100%

Fojtíková P. , Řádková L. , Janová D. , Krčma F.

Open Chemistry

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2015

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tom 13

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nr 1

EN

The aim of this work is the application of low-temperature low-pressure hydrogen plasma on artificially prepared corrosion layers, so called plasma chemical reduction. It is necessary to use samples with artificially prepared corrosion layers because it is impossible to use the real artifacts for fundamental research. The bronze was chosen as a sample material. Formation of corrosion layers on the bronze samples was carried out in concentrated hydrochloric acid vapors with the addition of sand. The radio-frequency hydrogen plasma was generated in the flowing regime at a pressure of 160 Pa. Different values of supplied power were chosen as well as different discharge modes: continuous or pulsed mode with varied duty cycles. By the combination of supplied power and mode factors, we selected two values of effective power. The process of plasma chemical reduction was monitored by optical emission spectroscopy (OES) and simultaneously, the sample temperature was measured. Rotational temperatures were calculated from OH radicals spectra. Changes in the structure and elemental composition were determined using scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX).

2

Analiza ilościowa składu pierwiastkowego na mikroanalizatorze rentgenowskim

86%

Piekoszewski W. , Tuszyński W.

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1999

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tom nr 1

269-281

PL

W referacie przedstawiono metody analizy ilościowej składu pierwiastkowego na mikroanalizatorze rentgenowskim. Omówiono zalety i wady stosowanych w Zakładzie Tribologii metod mikroanalizy. Przedstawiono wyniki badań przeprowadzonych na mikroanalizatorze Voyager 3050 firmy Noran Instruments z zastosowaniem procedur "wzorcowych" i "bezwzorcowych".

EN

The authors presents methods of X-ray quantitative analysis of elemental composition using energy dispersive spectrometer Voyager 3050 (Noran Instruments-USA). Two methods of quantitative analysis, i.e. standard and standardless were employed and the results are compared. Both virtues and drawbacks of the methods are pointed out.

3

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

72%

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.

4

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

72%

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.

5

Multilayer laser cladding of bronze powder for fast prototyping.

58%

Jendrzejewski R. , Śliwiński G.

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1998

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tom R. XIX, nr 4

1100-1103

EN

Process parameters of the multilayer laser cladding of the bronze B10 alloy powder are experimentally investigated. The 3-D structures are prepared trace-on-trace by remelting of the powder injected into the processing zone through a nozzle. An efficient formation of the volumetric structures of controlled geometry is observed. Microanalysis of the samples confirm the expected mechanical properties, low porosity and the highly homogeneous structure of the multilayers. For the subsequent clads of 1 mm width and 0,6 mm in height produced at velocities of 1m/min. the process efficiency of about 5% is obtained.

6

Microstructure of a composite padded layer of metal powders and its resistance to penetration with a hard core bullet

51%

Starczewski L.

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2008

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tom Vol. 53, iss. 1

247-251

EN

The article presents the followin g, thesis: an armour material with hardness gradient shall successfully withstand the impact of a bullet with a hard core (65HRC) if the hardness of the surface layer is higher than the hardness of the bullet core and the layer is deposited on a soft substrate. A ballistic experiment was conducted to examine the ability of a hard (72HRC) composite padded layer — made of metal powders deposited by the plasma technique on soft steel (180HB) — to withstand the impact of bullets with a hard core. The microstructure of the padding weld was identified and its chemical composition was analysed. The examined material system with hardness gradient was found to be able to withstand successfully the impact of bullets with a hard core, while core defragmentation was the dominant mechanism. The examination of microstructure demonstrated an interrelation between the mechanism and the structure of the padded material.

PL

W artykule postawiono tezę, że materiał na pancerz o właściwościach gradientu twardości skutecznie zatrzyma pocisk z twardym rdzeniem (65HRC), jeżeli twardość warstwy powierzchniowej będzie powyżej twardości rdzenia pocisku i będzie utworzona na miękkim podłożu. W eksperymencie balistycznym zbadano zdolność twardej (72HRC) kornpozytowej warstwy napawanej, utworzonej z proszków metali techniką plazmową na miękkiej stali (180HB), do zatrzymania pocisków z twardym rdzeniem. Przeprowadzono identyfikacje mikrostruktury i analizę składu chemicznego napoiny. Badany układ materiałowy o gradiencie twardości, potwierdził swoją skuteczność w zatrzymaniu pocisków. W procesie tym dominującym mechanizmem jest fragmentacja twardego rdzenia. Badania mikrostruktury ujawniły związek pomiędzy tym mechanizmem a budową strukturalną napawanego materiału.

7

Struktura i właściwości warstw powierzchniowych z faz międzymetalicznych Al-Ni na podłożach aluminiowych.

44%

Tacikowski M. , Khalid A. , Słoma J. , Wierzchoń T.

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2002

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tom R. XXIII, nr 5

676-679

PL

Materiały na osnowie faz międzymetalicznych z układu Al-Ni należą do grupy nowych materiałów o unikatowych właściwościach fizycznych, chemicznych i mechanicznych, stąd też poszukuje się metod ich wytwarzania również w postaci warstw powierzchniowych, zwłaszcza na podłożach z metali lekkich. W pracy zastosowano dyfuzyjną metodę otrzymywania warstw z faz międzymetalicznych układu Al-Ni. Metoda polega na obróbce cieplnej podłoży aluminiowych uprzednio pokrywanych różnymi rodzajami powłok niklowych. Przedstawiono wyniki badań strukturalnych warstw, w tym mikroskopii świetlnej i elektronowej, rentgenowskiej analizy fazowej i mikroanalizy rentgenowskiej oraz pomiarów twardości i badań odporności na zużycie przez tarcie.

EN

Intermetallic materials are well known for their very promising properties important from the point of view of the high temperature application. That is why this research area is very interesting equally for the scientists and for the industry, especially for the aeronautics. Perceptively attractive research problem is the development of methods of elaboration of intermetallic layers in particular on the light alloys substrates. In the present work the diffusion method was applied for the elaboration of the intermetallic Al-Ni layers. The method consists of the heat treatment of previously nickel coated aluminium substrates. The results of the microstructure studies with the use of light and electron microscopy, X-ray analyses as well as microanalyses were presented. The results of wear resistance and hardness characterisation are also shown.