Wyniki wyszukiwania - Biblioteka Nauki

1

Tribological characterization of high porosity aluminum based composite materials

100%

Stanev L. , Kolev M. , Yotov A. , Drenchev B. , Drenchev L.

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tom Vol. 57, no. 4

363--367

EN

The present work aims to study the effect of the reinforcing phase on dynamic coefficient of friction and mass wear of specimen with different compositions under various friction conditions. Porous materials with different compositions and reinforcing phase are obtained by replication method applying salt (NaCl) space holder. The reinforcing phase is Fly Ash (FA) particles. The microstructure of the obtained materials is observed and the tribological properties such as mass losses and the dynamic coefficient of friction are determined. A comparison of the tribological properties between nominally nonporous matrix, porous matrix and porous composite are presented in this study.

2

Effect of granularity of reinforcing particles Al2O3 on EDM process of aluminium matrix composites

100%

Perończyk J.

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tom Vol. 12, No. 2

67--76

EN

The study discusses issues related to the process of electro-discharge machining (EDM) composites based on Al + 20% Si + 5% Fe + 3% Cu + 1% Mg matrix manufactured using a powder metallurgy method. Ten percent by volume of Al2O3 grains of 3, 9, 23 and 53?m sizes with irregular sharp edges represented the reinforcing phase. EDM was performed with a machine equipped with a RLC generator using different (computational) discharge energies varied in steps within the 0.044 - 2.268 mJ range. The tests measured volumetric productivity of EDM (Vw) and roughness (Ra) of the machined surface. In addition, the researchers provided selected SEM images of ED-machined surfaces with some results of X-ray microanalyses of chemical composition performed in cavities and on the surfaces of irregularities. They also provided SEM images of Al2O3 grains adhering to the machined surface of the composite, showing the mechanism of erosion of dielectric particles in EDM conditions. They demonstrated that the energy of single discharges (Ei) was the main parameter effecting the process and results of EDM. The volumetric productivity of the process (Vw) and roughness of the machined surface (Ra) increase with growth of energy (Ei) and, at the same time, surface integrity (SI) changes.

3

Odkształcalność kompozytów na osnowie stopów aluminium wzmacnianych cząstkami węglika krzemu. Cz. I. Kompozyty - klasyfikacja, metody wytwarzania, własności mechaniczne, zastosowanie.

75%

Kurtyka P. , Płonka B. , Wierzbiński S.

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tom R. 45, nr 1

23-28

PL

Na podstawie studiów literaturowych w artykule przedstawiono kryteria klasyfikacji kompozytów, rodzaje i formy faz zbrojących kompozyty z uwzględnieniem reakcji na granicy osnowa-faza zbrojąca. Omówiono także podstawowe zagadnienia związane z wytwarzaniem kompozytów, w tym głównie kompozytów na osnowie metalowej wzmacnianych cząstkami węglika krzemu, jak również metody oceny ich własności mechanicznych w aspekcie zastosowań przemysłowych.

EN

Criterions of composites' classification, the kinds and forms of the phases reinforcing composites, taking into account the reactions on the matrix-reinforcing phase are presented, grounded on literary studies. The principal problems bound with generation of composites, especially of metal-matrix ones, reinforced with particles of silicon-carbide, and the methods of evaluation of their mechanical properties for industrial applications are talked over.

4

The influence of the forced movement of components on the structure in fabricated AlSi/CrxCy composite castings

75%

Dulęba A. , Cholewa M. , Scelina D.

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tom Vol. 12, iss. 1

25-32

EN

Fabrication and microstructure of the AlSi11 matrix composite containing 10 % volume fraction of CrFe30C8 particles were presented in this paper. Composite suspension was manufactured by using mechanical stirring. During stirring process the temperature of liquid metal, time of mixing and rotational speed of mixer were fixed. After stirring process composite suspension was gravity cast into shell mould. The composites were cast, applying simultaneously an electromagnetic field. The aim of the present study was to determine the effect of changes in the frequency of the current power inductor on the morphology of the reinforcing phase in the aluminum matrix. The concept is based on the assumption that a chromium-iron matrix of CrFe30C8 particles dissolves and residual carbide phases will substantially strengthen the composite. The microstructure and interface structure of the AlSi11/CrFe30C8 composite has been studied by optical microscopy, scanning microscopy and X-ray diffraction.

5

Wybrane właściwości kompozytów metalowych wzmacnianych cząsteczkami ceramicznym

51%

Mazurkiewicz A.

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tom nr 6

PL

Kompozyty metalowe na osnowie stopów aluminium, stanowią coraz częściej stosowaną grupę materiałów konstrukcyjnych. Wynika to z możliwości pracy w podwyższonych temperaturach, korzystnej wartości wytrzymałości właściwej jak też odpornością na zużycie ścierne umożliwiając pracę w warunkach tarcia technicznie suchego np. w parze ciernej tarcza hamulcowa-okładzina cierna. Określono ważniejsze parametry opisujące właściwości materiału, zwracając uwagę na problemy sterowania tymi czynnikami.

EN

Metal composite on the warp of the alloys of aluminum, makes up the applied group of constructional materials more and more often. This results from the possibility of working in raised temperatures, profitable value of proper endurance as also the resistance on the abrasive waste make possible working in conditions of the technically dry friction e.g. brake shield or friction facing in the abrasive steam. More important parameters describing proprieties of the material were defined, returning the attention to the problems of steering these factors.