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Właściwości mechaniczne i optyczne szkieł z powłoką tlenku cyrkonu otrzymaną metodą zol-żel

Drajewicz M., Jadach R., Długoń E., Reben M., Sitarz M.

Materiały Ceramiczne

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2015

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T. 67, nr 2

187--190

PL

Podstawowym parametrem ograniczającym wykorzystanie szkieł często jest ich niezadowalająca wytrzymałość mechaniczna. Poprawę wytrzymałości mechanicznej szkieł można uzyskać między innymi poprzez naniesienie na ich powierzchnię cienkich warstw. Warstwy te charakteryzują się lepszymi właściwościami mechanicznymi, a połączenie tych materiałów powoduje poprawę wypadkowych właściwości szkła. Przedmiotem badań było szkło krzemianowo-sodowo-wapniowe pokryte warstwą tlenku cyrkonu. Do naniesienia warstwy tlenku cyrkonu użyto metody zol-żel. Warstwy poddano badaniom mechanicznym, w szczególności zmierzono twardość metodą Vickersa oraz moduł sprężystości. Przepuszczalność szkieł z nałożonymi warstwami zbadano przy wykorzystaniu spektroskopii UV/VIS. Przeprowadzone badania wskazały na potencjalną przydatność wybranej metody do uszlachetniania powierzchni szkieł.

EN

Unsatisfied mechanical strength frequently limits the usage of glasses. Its improvement can be attained by coating the glass surface with a thin layer of material with better mechanical properties than the glass. Silicate-sodium-calcium glass coated with zirconia was the object of this study. The sol-gel method has been used to produce a coating of zirconia. Vickers’ hardness and Young’s modulus were determined for the coatings. Transmittance of the coated glasses was determined by UV/VIS spectroscopy. The applied sol-gel method was useful to improve properties of glass surfaces.

2

Load dependence of hardness of the doped soda-lime silicate glasses

Suszynska M.

Optica Applicata

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2012

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Vol. 42, nr 2

399-406

EN

The aim of the work described was to study the load dependence of micro- and nano-hardness for soda-lime silicate glass doped with some univalent cations. The Fourcault-type glass samples were chemically treated by dipping them in melted baths of KNO3, AgNO3 and CuCl. The nano- and micro-hardness were determined by using the Vickers diamond indenters for applied loads ranging between 0.1 and 500 mN (registered loading and unloading mode), and between 0.2 and 30 N (conventional application of the load), respectively. For the behavior of hardness and Young's modulus (registered nano-indentation) the normal indentation size effect has been observed, but in the low load range of conventionally indented specimens the reverse indentation size effect has been found. The detected size effects were discussed in terms of some empirical models proposed in the literature for crystalline materials. It has been shown that: 1) the Meyer's law is only suitable for describing the nano-indentation characteristics measured in a narrow range of indentation load; 2) the classical Meyer's law and the energy balance model are insufficient for describing the reverse indentation size effect; 3) the difficulties in acquiring accurate and precise micro-hardness readings in the range of low loads can result in the inconformity of experimental data with the empirical models.

3

Dosimetric properties of gammaand electron-irradiated commercial window glasses

Fuochi P., Corda U., Lavalle M., Kovács A., Baranyai M., Mejri A., Farah K.

Nukleonika

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2009

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Vol. 54, No. 1

39-43

EN

Two different types of window glasses have been investigated as possible routine dosimeters in the range of 1-50 kGy. Glass samples were irradiated with 3.4 MeV and 8.4 MeV electron beams and the results compared with those obtained by 60Co gamma irradiation. Due to the strong optical absorption at wavelengths ess than 310 nm, even at low doses, optical measurements were limited to the range 320-700 nm. In both types of glasses, irradiation induced two absorption bands around 410 and 600 nm the intensities of which are proportional to dose; the 600 nm band being less sensitive to radiation. These bands have been attributed to non bridging oxygen hole centres existing in two different configurations. Because of the rapid fading of the optical absorbance observed at room temperature immediately after irradiation (greater than 15% in two days), the samples underwent a post-irradiation thermal treatment (150 graduate C for 20 min) to improve the stability of absorbance. The fading characteristics of the irradiated and thermally treated glasses, kept in the dark at room temperature, were studied for several weeks. A fast decay, whose intensity depends on the type and energy of the ionizing radiation, was observed for few days after irradiation and thermal treatment, followed by a much slower decay. The results show that this kind of material could be used as routine dosimeters within a certain dose range, as long as proper calibrations are made for each batch of glass and the appropriate precautions are taken when doing calibration and performing routine dosimetry.

4

Razušenie materialov pri dinamičeskom kontaknom nagruženii

Bogdanovič P., Tkačuk D., Bliznec D.

Acta Mechanica et Automatica

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2007

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Vol. 1, no. 1

15-18

EN

The paper reports data on the kinetics, failure mechanism, and wear rate of silicate glass and sapphire in high-speed abrasive machining. Regularities of the effect of the load the velocity of abrasive particle movement, and the duration of the cutting of sapphire and the diamond monocrystal on temperature fields in the cutting zone and adjacent areas are discussed. I is shown that at high velocities me maximal surface temperature position shifts outside the contact site and temperature stresses cause the thermal cracking of sapphire and glass in this zone. When cutting a diamond monocrystal the temperature in the cutting zone can reach values sufficient for its local graphitization to occur.