Wyniki wyszukiwania - Biblioteka Nauki

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Structure and properties of amorphous and nanocrystalline Fe78Si11-xB11Yx(x = 0 or 2) alloys produced in a single production step using controlled parameters melt-spinning method

100%

Błoch K.

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tom Vol. 73, nr 1

5--12

EN

Purpose: The paper presents results of structural and magnetic properties of Fe78Si11B11 and Fe78Si9B11Y2 alloys in the form of ribbons. The effect of addition of yttrium on the structure and magnetic properties was investigated. Design/methodology/approach: The investigated samples were prepared in the form of ribbons using the melt-spinning method. The material structures were investigated using X-ray diffractometry, Mössbauer spectroscopy and scanning electron microscopy. The magnetic properties were studied using using vibrating magnetometer. Findings: Samples were fabricated using rapid cooling at a rotating copper wheel. Images of fractures of investigated samples obtained by decohesion using same magnifications are similar. The distinct vein like structure or the husk structure are not visible thought they are typical of amorphous and nanocrystalline materials with a high degree of internal stress. Mössbauer spectrum is typical as for amorphous materials that are ferromagnetic. It consists of six lines forming a Zemman's sextet. The hyperfine induction field distribution obtained for this sample shows clearly separated two components: low- and high-field. After the introduction of 2% at. Y to the alloy Fe78Si11B11 in place of Si partial crystallization occurred. The shape of the initial magnetization curves is similar and corresponds to materials with low effective anisotropy. Originality/value: The paper presents some researches of the Fe-based bulk amorphous alloys obtained by the melt-spinning method.

2

Comparison of results obtained using the injection method of preparation of solid amorphous alloys with and without suction

100%

Klimas J. , Łukaszewicz A. , Szota M. , Nabiałek M. , Dobrzańska-Danikiewicz A.

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2014

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tom Vol. 67, nr 2

77--83

EN

Purpose: The study compares the structure and properties titanium alloy Ti-6Al-4V produced by injection method allowing the production of massive amorphous materials in two varies – with and without suction. Design/methodology/approach: Samples were produced form titanium alloy Ti-6Al-4V produced by injection method. Structures and properties were compared of the same alloy but with different conditions in production process – with and without suction. To achieve the objective perused the following tests were carried out: study of phase composition by X-ray diffraction, observation of microstructure by using optical microscope and SEM, study of surface geometry – roughness, abrasion resistance tests and microhardness tests. Results: Microstructural studies have allowed to observe that the titanium alloy Ti-6Al-4V produced by injection method in both varies – with and without suction during injection to copper mold, has structure partially crystalized – nanocrystalline. In structure occur the crystal nuclei and lack of arrangement and regularity. The study of microhardness showed 100 HV 0.1 units higher hardness value in the embodiment with suction in comparison to the variant without suction. Titanium alloy Ti-6Al-4V produced with suction has better abrasion resistance in comparison with same alloy without suction. Alloy produced with suction has lower development area. Originality/value: The paper presented studies of massive amorphous and nanocrystalline alloys produced by alternative method – injection casting in two variants – with and without suction. That kind of production allow produced alloys with same chemical composition as commercial but with far better properties.

3

Struktura warstw żaroodpornych MeCrAlY+AlSi otrzymywanych metodą Arc-PVD na monokrystalicznym stopie CMSX-4.

70%

Swadźba L. , Hetmańczyk M. , Mendala B. , Saunders S. R. J.

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tom R. XXIII, nr 5

390-394

PL

W artykule przedstawiono wyniki badań nad otrzymywaniem warstw żaroodpornych na żarowytrzymałym stopie niklu metodą Arc-PVD z wykorzystaniem reakcji prowadzących do utworzenia faz międzymetalicznych Ni-Al. Po obróbce cieplnej w temperaturze 1050 stopni Celsjusza w próżni otrzymano warstwy żaroodporne 21% at. Al. i 50 mikrometrów grubości. W następnym etapie osadzano warstwy typu MeCrAlY o zróżnicowanym składzie chemicznym. Pokrycia MeCrAlY otrzymywano z dwóch targetów. Wykazano dobrą zgodność składu chemicznego targetów i pokryć, oraz ich równomierne rozmieszczenie. Następnie powierzchnię pokrywano aluminium metodą Arc-PVD po czym zmieniano parametry procesu tak aby doprowadzić do syntezy pomiędzy NiCoCrAlY i Al z utworzeniem pokrycia którego osnowę stanowiła faza NiAl z wysoką zawartością Co, CrNi oraz Y. Końcowa obróbka cieplna przeprowadzona w temperaturze 1323 stopni Celsjusza w atmosferze ochronnej doprowadziła do ostatecznego uformowania struktury pokrycia. Wykazano możliwość otrzymywania międzymetalicznej warstwy beta-NiAl modyfikowanej innymi pierwiastkami zwłaszcza chromem i itrem. Pokrycia otrzymywano na monokrystalicznym stopie CMSX-4.

EN

Investigations of depositing high temperature resistant coatings on the Ni base superalloys by the Arc-PVD method using exothermic reaction processes between Ni and NiAl intermetallic formation are presented in the article. By the diffusion heating at 1050 degrees centigrade in vacuum, NiAl diffusion coating containing 21% at. Al and 50 micrometers thick were obtained. In the next stage coatings with more complex chemical composition - MeCrAlY were formed. The MeCrAlY coatings were made from two targets. Good correlation between the chemical composition of the targets and a uniform distribution of elements in the coatings was shown. Then the surface was also covered with aluminium by the Arc-PVD method. In the vacuum chamber of the equipment a synthesis reaction between NiCoCrAlY and Al with the formation of NiAl intermetallics of high Co, Cr, Y content was initiated. The final heat treatment of coatings was conducted in vacuum at 1323K. Strong segregation of yttrium into the oxide scale in the specimens heated in the air was shown. It was possible to form NiAl and intermetallics phase coatings modified by Co, Cr and Y by the Arc-PVD method. The coatings were formed on single crystal CMSX-4. The structure, morphology and phase composition of coatings was carried out.