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1

Microstructure of ultrafine-grained Al produced by severe plastic deformation

Rodak K., Pawlicki J.

Archives of Materials Science and Engineering

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2007

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Vol. 28, nr 7

409-412

EN

Purpose: The structure of Al subjected to severe plastic deformation by means of compression with oscillatory torsion and by combined method (compression followed by compression with oscillatory torsion) were investigated. Design/methodology/approach: Al samples were deformed at torsion frequency (f) changed from 0 Hz (compression) to 1.6 Hz under a constant torsion angle (α) ≈ 6° and compression speed (v)=0.1mm/s. For combined methods the samples were compressed for strain ε = 0.7 and next deformed at mentioned parameters of compression with oscillatory torsion. Structural investigations were conducted by using light microscopy (LM) and transmission electron microscopy (TEM). Findings: The structural analysis made by TEM shows that the processing by compression with oscillatory torsion ensures obtaining a structure (at selected parameters) with a mean grain size ≈ 1.6 µm. Combined methods of deformation lead to grain refinement to about ≈ 0.9µm moreover material with uniform ultra-fine grained (UFG) microstructure was obtained. Research limitations/implications: The understanding in refinement of Al structure could help to modify the process and design deformation parameters. Practical implications: The knowledge of the characteristic features of unconventionally deformed materials will provide the usefulness of the employed method to produce materials having the desirable functional properties. Originality/value: Oscillatory compression is a deformation procedure applied to achieve large strains. However there is no studies on evolution of the microstructures during deformation by using mentioned mode. This paper provides these information's.

2

Microstructure characterization of deformed copper by XRD line broadening

Rzychoń T., Rodak K.

Archives of Materials Science and Engineering

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2007

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Vol. 28, nr 10

605-608

EN

Purpose: The aim of the present study was to determine the changes in microstructure taking place during deformation with methods like compression, compression with oscillatory torsion as well as compression and subsequent compression with oscillatory torsion (combined method). Design/methodology/approach: The study was conducted on M1E grade Cu. Several methods were used in this study, such as: transmission electron microscopy and X-ray diffraction. The X-ray diffraction line profile analysis was applied to determine crystallite size and density of dislocations. Findings: Application of compression and oscillatory torsion without previous compression resulted in decrease of grain size and crystallite size and increase of lattice distortion caused by dislocation compared to the combined method of deformation. In specimen with higher microstrain and smaller grain size a higher fraction of edge dislocations was observed. Research limitations/implications: Obtained results can be useful to modify the process and design deformation parameters. Practical implications: The knowledge of the characteristic features of unconventionally deformed materials will provide the usability of the method employed to produce materials with desired functional properties. Originality/value: Compression with oscillatory compression is a deformation procedure applied to achieve large strains. However there is no studies on evolution of the microstructures during deformation obtained on the way of the methods mentioned above. This paper provides such an information.

3

Transmission electron microscopy in plasma surface interaction in fusion research.

Hirai T., Linke J., Majerus P., Rödig M.

Archives of Materials Science

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2005

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Vol. 26, nr 1-2

89-94

EN

Transmission electron microscopy (TEM) is a powerful method to study the microstructure of plasma facing materials in fusion devices. The main topics that have been presented so far are the observation of radiation damage caused by particle bombardment and the characterization of deposits and dust created in fusion devices and transient heat load events. The present work summarizes the recent TEM works in this field and the possible use of TEM studies in high heat flux testing.

4

Strengthening and the interplay of slip and twinning in copper-titanium alloys.

Radetic T., Radmilovic V., Soffa W.A.

Inżynieria Materiałowa

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1999

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R. XX, nr 1

32-35

5

Processing and mechanical properties of mechanically alloyed niobum-rich Nb-Al alloys.

Dymek S., Dollar M., Leonard K., Wróbel M.

Inżynieria Materiałowa

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1998

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R. XIX, nr 4

1147-1152

EN

Four Nb-Al alloys containing 15%, 18%, 20% and 25% at. Al were successfully processed by mechanical alloying followed by hot pressing. Analysis of X-ray spectra as well as transmission electron microscopy studies revealed the presence of four phases: niobum solid solution (Nbss), NB3Al, Nb2Al and dispersoids of Al2O3. The grain size was estimated to be = 1 micrometre. The improvement in strength of the mechanically alloyed material was due to the refined grain size and oxide dispersion in the microstructure. The alloys exhibited only limited compressive ductility at room temperature but were ductile at 1000 degrees centigrade. The mechanism for creep deformation in the examined Nb-Al alloys is postulated to be dislocation creep through diffusion controlled climb.

6

Micro- and nano- structural observations of the surface layer of hardened bearing steel.

Barbacki A., Kozubowski J.A., Kawalec M.

Inżynieria Materiałowa

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1998

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R. XIX, nr 4

978-981

EN

The paper presents the results of TEM and HREM investigations of the surface layer produced in a hardened 1% C, 1.5% Cr steel by dry machining. The investigations have revealed extremly small micro- and nano- grains probably resulting from large plastic deformation accompanied by localised stress-induced martensite to ferrite transformation and dynamic recovery.

7

Electrical properties and transmission electron microscopy study on sputtered Cu/Ni multilayer films.

Worek C., Jankowski H., Ciura F.

Inżynieria Materiałowa

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1998

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R. XIX, nr 4

840-843

EN

Electrical properties as well as the structure and morphology of multilayered Cu/Ni films deposited by magnetron sputtering were investigated. The influence of the deposition and annealing parameters on the temperature coefficient of resistance (TCR) and sample resistivity were determined. Using TEM images the dependence of the grain size of crystalline films on the sublayer Cu and Ni thickness and annealing temperature was investigated.