Wyniki wyszukiwania - BazTech

1

Badania wiązania mocznika w procesie otrzymywania nawozów mocznikowo-superfosfatowych

Sadłowski M., Grzmil B., Lubkowski K.

Przemysł Chemiczny

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2016

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T. 95, nr 1

114--117

PL

Badano zdolność mocznika do tworzenia połączeń addycyjnych ze składnikami pulp superfosfatowych, takimi jak CaSO4 nH2O (gdzie n = 0–2) i Ca(H2PO4)2⋅H22O. Reakcje prowadzono ucierając wysuszony nawóz superfosfatowy z mocznikiem w młynie moździerzowym lub dodając mocznik do reaktora rozkładu fosforytu kwasami (H2SO4 lub H3PO4). Skład fazowy produktów badano metodą dyfrakcji rentgenowskiej. Stwierdzono, że najłatwiej przebiega reakcja mocznika z Ca(H2PO4)2⋅H2O, a w dalszej kolejności z CaSO4⋅2H2O i CaSO4⋅0,5H2O. W żadnym z prowadzonych doświadczeń nie zaobserwowano reaktywności mocznika z bezwodnym CaSO4.

EN

Urea additive compds. with superphosphate pulp components (Ca(H2PO4)2⋅H2O and CaSO4⋅nH2O, where n = 0–2), were prepd. The exps. were carried out (i) by milling urea with a dry superphosphate fertilizer in a lab. mortar grinder or (ii) by urea addn. to the reactor after phosphate rock decompn. with H2SO4 or H3PO4. The phase compn. Of products was studied by X-ray powder diffraction method. Ca(H2PO4)2⋅H2O was more reactive than CaSO4⋅2H2O and CaSO4⋅0.5H2O in the urea complexation. The reactivity of anhyd. CaSO4 towards urea was not obsd. in any expt.

2

Monitorowanie bezpieczeństwa konstrukcji stalowych

Juraszek J.

Logistyka

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2015

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nr 3

1985--1993, CD 1

PL

W pracy zaproponowano nowe podejście monitoringu bezpieczeństwa konstrukcji ferromagnetycznych. Polega on na systematycznej budowie baz danych magnetogramów dla wybranych rodzajów konstrukcji ferromagnetycznych począwszy od początku ich eksploatacji, a następnie w każdym etapie ich eksploatacji wraz z odniesieniem do próbek wzorcowych. Takie podejście możliwi wykrywanie i identyfikację powstających w konstrukcjach ferromagnetycznych obszarów koncentracji naprężeń oraz rejonów niebezpiecznych z pęknięciami. Na podstawie analizy magnetogramów będzie można podjąć działania zapobiegawcze odpowiednio wcześniej, polegające na wymianie stosownego elementu bądź wzmocnieniu konstrukcji. Skalibrowanie wartości magnetycznych z wartościami mechanicznymi za pomocą metody dyfrakcji rentgenowskiej stanowi nowe podejście w ocenie wytężenia konstrukcji za pomocą badań magnetycznych.

EN

The paper proposes a new approach in the monitoring the safety of ferromagnetic structures. It involves the systematic construction of databases of magnetograms for selected types of ferromagnetic structures, starting from the beginning of their exploitation, and then at each stage of their exploitation with reference to standard samples. This approach will make it possible to detect and identify emerging stress concentration and hazardous areas with cracks in ferromagnetic constructions. Based on the magnetograms analysis, preventive measures could be taken in advance, involving the exchange of relevant element or strengthening the structure. The calibration of magnetic values with mechanical ones using X-ray diffraction method, represents a new approach in assessing construction effort using magnetic testing.

3

Zmiany poziomu naprężeń własnych w stemplach do wyciskania przeciwbieżnego wyrobów z cynku

Samolczyk J.

Obróbka Plastyczna Metali

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2011

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T. 22, nr 4

255-268

PL

W artykule przedstawiono wyniki badań naprężeń własnych w warstwie powierzchniowej stempli do wyciskania przeciwbieżnego wyrobów z cynku. Pomiarów naprężeń dokonano rentgenowską metodą sin 2, która okazała się przydatną do wyznaczania naprężeń własnych w stemplach do wyciskania przeciwbieżnego metali. W przypadku stempli do wyciskania przeciwbieżnego wyrobów z cynku, czas eksploatacji narzędzi wyraźnie zależy od rodzaju naprężeń panujących w ich warstwie wierzchniej. Naprężenia ściskające przy powierzchni zapewniają bezpieczną eksploatację stempli do wyciskania. Zmiana naprężeń ściskających na naprężenia rozciągające w warstwie wierzchniej powoduje przyspieszenie zużycia narzędzi.

EN

The paper presents the results of investigation of internal stresses in the surface layer of punches for backward extrusion of zinc products. Stress measurements have been effected by the x-ray sin 2 method which proved to be suitable for the determination of internal stresses in punches for backward extrusion of metals. In the case of the punches for backward extrusion of zinc products, the tool exploitation time is clearly dependent on the kind of stresses present in their surface layer. Compressive stresses at the surface result in safe exploitation of extrusion punches. The change of compressive stresses into tensile ones accelerates the tool wear.

4

Residual stresses in the strips from copper-based alloys

Staszewski M., Rdzawski Z. M., Wrona A.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 25, nr 2

35-38

EN

Purpose: The aim of this work was to define the stress state in the strips from copper-based alloys with an account of the parameters of rolling and flattening. Design/methodology/approach: Samples of thin strips from three commercial copper-based alloys, i.e. CuSn6, CuZn33 and CuNi18Zn27, and from copper 99.98% in purity, were examined. The stress analysis was performed using X-ray diffraction method. The macro-stresses were determined by the measurements of the changes in a lattice constant and by the "square sin psi" technique. The micro-stresses were measured by the diffraction line broadening method. Findings: It was found that the residual stresses, measured at both surfaces of the cold rolled strip, depend strongly on the rolling conditions and on rolling gap geometry. Considerable differences between these surfaces have been observed before and after the flattening process. However, they can be significantly reduced by suitably conducted flattening process. Research limitations/implications: Further studies are necessary to assess the possibility of reducing stresses on both surfaces of a strip in the case of non-ideal shape of rolls in a rolling mill. Practical implications: Modification of technological flowchart for rolling strips from hardly-deformable copper-based alloys enables obtaining the required dead flatness of the strips. Originality/value: The results from this work can be used to improve the technology of rolling and flattening thin strips from copper and copper-based alloys.

5

Influence of crystallisation an amorphous Co77Si11.5B11.5 alloy on corrosion behavior

Nowosielski R., Zajdel A., Baron A., Lesz S.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 20, nr 1-2

167-170

EN

Purpose: This paper describes crystallization kinetics and its influence on changes of electrochemical behavior of amorphous, amorphous relaxed and nanocrystalline Co77Si11,5B11,5 alloy. Design/methodology/approach: The following experimental techniques were used: structural research - X-ray diffraction (XRD) and electrochemical investigations were carried out by means of an electrochemical impedance spectroscopy method. Findings: Heat treatment of amorphous Co77Si11,5B11,5 alloy leads to the formation of the hexagonal alpha-Co phase in an amorphous matrix at the temperature T = 798 K and this is the first stage of the crystallization process. At the temperature T = 873 K appearance of boride phase Co2B, Co3B and silicates phase Co2Si was state. It is the second stage of crystallization. The existence of boride phases was confirmed by after annealing in the temperature range from 730 K up to 873 K. The secondary crystallization is known to cause grain coarsening of phases and the electrochemical properties. The analysis leads to the conclusion that in view of data obtained from electrochemical tests in 3% NaCl solution, the crystallization process begins at lower temperatures than resulting from XRD data Co77Si11,5B11,5 alloy. Practical implications: The attractive properties of Co-Si-B alloy are of special interest for basic research on the materials as well as for their potential applications. Due to their numerous potential application nanocrystalline cobalt based alloys could be work in a wet industrial and marine atmosphere containing sulphide and chloride ions. Electrochemical corrosion can changes structure and magnetic properties of Co-based alloys. Originality/value: It has been shown that thermal annealing at temperature lower than the crystallization temperature leads to a significant changes of the initial electrochemical behaviour in 3% NaCl solution.

6

Crystallization kinetics of an amorphous Co77Si11.5B11.5 alloy

Nowosielski R., Zajdel A., Lesz S., Kostrubiec B., Stokłosa Z.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 17, nr 1-2

121--124

EN

Purpose: This paper describes crystallization kinetics and changes magnetic properties involved by process of crystallization Co-Si-B amorphous alloy. Design/methodology/approach: The following experimental techniques were used: X-ray diffraction (XRD), electrical resistivity in situ measurements (four-point probe) static and dynamic measurements of magnetic properties (magnetic balance, fluxmeter, Maxwell-Wien bridge). Findings: In this work has been performed influence of thermal annealing on crystallization kinetics and magnetic properties amorphous Co77Si11.5B11.5 alloy. Practical implications: The attractive properties of Co-Si-B alloy are of special interest for basic research on the materials as well as for their potential applications, like magnetic sensors. The Co soft magnetic material is used in noise filters, saturable reactors, miniature inductance elements for abating spike noise, mains transformers, choke coils, zero-phase current transformers, and magnetic heads etc., i.e., devices which are expected to exhibit high levels of permeability at high frequencies. Originality/value: It has been shown that thermal annealing at temperature close to the crystallization temperature leads to a significant increase of the initial magnetic permeability.

7

Crystallisation kinetics and magnetic properties of a Co-based amorphous alloy

Lesz S., Nowosielski R., Kostrubiec B., Stokłosa Z.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 16, nr 1-2

35--39

EN

Purpose: In the present paper, the kinetics of crystallization process and its correlation with magnetic properties of the Co80Si9B11 alloy was carefully examined. Design/methodology/approach: The following experimental techniques were used: X-ray diffraction (XRD), electrical resistivity in situ measurements (four-point probe), saturation magnetization in situ measurements (magnetic balance) and initial relative magnetic permeability measurements (Maxwell-Wien bridge). Findings: The investigations proved that thermal annealing of amorphous Co80Si9B11 alloy leads to a crystallization process and radical changes of magnetic properties. The activation energy of this process was determined as Ec=3.0±0.2 eV. Research limitations/implications: According to the results presented in the present paper the examined alloys can be used as a very good soft magnetic material. Originality/value: The best soft magnetic properties are observed in as quenched state.