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Number of results: 6
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Abstract

In this topic review the results of the X-band electron paramagnetic resonance (EPR) measurements of Mn, Co, Cr, Fe ions in YAlO3 (YAP) crystals and Fe ions in LiNbO3 (LNO) crystals and of chromium doped Bi12GeO20 (BGO) and Ca4GdO(BO3)3 single crystals, are presented. It is well known that the oxide crystals (for example:YAP, LNO, BGO) are one of the most widely used host materials for different optoelectronic applications. The nature of point defect of impurities and produced in the oxide crystal after irradiation by bismuth ions and after irradiation by the 235U ions with energy 9.47 MeV/u and fluency 5 × 1011 cm−1 is discussed. The latter is important for applications of these oxide crystal as laser materials.

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Authors and Affiliations

I. Stefaniuk
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Abstract

In the work results of research on electrodischarge machining (EDM) of titanium alloy Ti10V2Fe3Al with (α + β) structure were presented. Preliminary heat treatment of samples allows to obtain different morphology and volume fraction of the α phase. The main goal of research was to assessment of the material microstructure impact on EDM technological factors (ie. material removal rate, tool wear) and morphology of technological surface layer. Electrodischarge machining is alternative and increasingly used method of titanium alloys machining. Research allowed to indicate the possibilities and limitations of use EDM in this area. It is especially important in the aspect of parts produced for aircraft industry and related requirements for the technological surface layer quality.

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Authors and Affiliations

A. Żyra
R. Bogucki
S. Skoczypiec
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Abstract

In this study, medium-carbon steel was subjected to warm deformation experiments on a Gleeble 3500 thermosimulator machine at temperatures of 550°C and 650°C and strain rates of 0.001 s–1 to 1 s–1. The warm deformation behavior of martensite and the effects of strain rate on the microstructure of ultrafine grained medium-carbon steel were investigated. The precipitation behavior of Fe3C during deformation was analyzed and the results showed that recrystallization occurred at a low strain rate. The average ultrafine ferrite grains of 500 ± 58 nm were fabricated at 550°C and a strain rate of 0.001 s–1. In addition, the size of Fe3C particles in the ferrite grains did not show any apparent change, while that of the Fe3C particles at the grain boundaries was mainly affected by the deformation temperature. The size of Fe3C particles increased with the increasing deformation temperature, while the strain rate had no significant effect on Fe3C particles. Moreover, the grain size of recrystallized ferrite decreased with an increase in the strain rate. The effects of the strain rate on the grain size of recrystallized ferrite depended on the deformation temperature and the strain rate had a prominent effect on the grain size at 550°C deformation temperature. Finally, the deformation resistance apparently decreased at 550°C and strain rate of 1 s–1 due to the maximum adiabatic heating in the material.

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Authors and Affiliations

Q. Yuan
G. Xu
S. Liu
M. Liu
H. Hu
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Abstract

Railway buffers during the operation are staying in almost permanent contact with each other, creating friction node in the point of contact

of two railway buffer heads. In consequence of overcoming track curves, turnouts and unevenness of track, the railway buffer heads moves

relative to each other causing friction, which results in its wear. When the wear is excessive, it might be a reason to withdrawn vehicle

from service, it causes flattening of buffer head, and in consequence its abnormal cooperation. To avoid this phenomenon the buffer heads

should be covered with graphitized grease, but this method has many disadvantages. Accordingly, it was found that it would be beneficial

to cover the buffer head with bronze using laser cladding. In this article the metallographic and mechanical analysis of the newly created

top layer of railway buffer head are presented. In article the results from tribological tests conducted on Amsler test bench are also

presented. Based on test results described in article concluded that the layer of bronze coat on working surface of railway buffer head can

be beneficial from operational point of view.

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Authors and Affiliations

M. Sitarz
A. Kurc-Lisiecka
W. Gamon
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Abstract

Multiferroic six-layer Aurivillius type Bi7Fe3Ti3O21 ceramics was obtained by conventional mixed oxides method. The final sintering process was taken in several different sintering times, which determined changes in properties of discussed ceramic material. The structure and dielectric properties of the material are reported. In order to examine the technological conditions on the crystal structure, XRD analysis was carried out. The microstructure, as well as the quantitative and qualitative analysis of the chemical composition were investigated by scanning electron microscope with an energy dispersion spectrometer. The main purpose of the paper is to present the effect of sintering time on the microstructure, crystallographic structure and dielectric properties of Bi7Fe3Ti3O21 ceramics.

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Authors and Affiliations

D. Szalbot
ORCID: ORCID
J.A. Bartkowska
K. Feliksik
M. Bara
M. Chrunik
M. Adamczyk-Habrajska
ORCID: ORCID

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