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1

The effect of deformation degree on the microstructure of the 6060 aluminium alloy

Koralnik M., Adamczyk-Cieślak B., Kulczyk M., Mizera J.

Archives of Materials Science and Engineering

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2017

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Vol. 85, nr 2

80--85

EN

Purpose: All results obtained in the present study allowed to analyse the changes in the microstructure and texture of the commercial 6060 aluminium alloy, after deformation process by severe plastic deformation. There were compare two deformation degree samples received by cumulative hydrostatic extrusion. Design/methodology/approach: The samples of the 6060 alloy were subjected to a onepass and three-passes extrusion process and next the age hardening. The microstructure changes were investigated by using transmission and scanning electron microscopy. To study the texture evolution the X-ray diffraction were made. Findings: The microscopic observations results presented the refinement of microstructure as a result of deformation process. The evolution of fibrous character of texture was observed. There were noted the disappearance of fibrous component <100> during subsequent deformation processes and generation the fibrous component <111> after high deformation degree. In addition, for each state, the presence of cubic texture component was recorded. Research limitations/implications: For the future research are planned to analyse changes in mechanical properties after hydrostatic extrusion combinate with age hardening of investigated materials. Originality/value: The paper focuses on the investigation of microstructure and texture evolution after modern method of plastic deformation.

2

Evaluation of Sb effect onto eutectic Si changes and mechanical properties in an 4xxx Al cast alloys series

Hurtalova L., Tillova E., Chalupova M., Farkasova M.

Production Engineering Archives

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2014

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Vol. 3, No. 2

2--5

EN

The purpose of this article is to examine the effect of modifier based on AlSb10 on the structure and mechanical properties of the AlSi7Mg0.3 and AlSi6Cu4 cast alloys. The changes of these parameters were studied on samples in untreated states (without heat treatment). Structural changes were studied on light and scanning electron microscopes. Several types of etching were used, which included normal black and white etching (0.5% HF), colour etching (Weck-Al) and deep etching (HCl), for studying structural parameters morphology. The influence of modifier on mechanical properties (UTS, Brinell hardness test) was studied at room temperature. The present work shows that the antimony has not had a significant effect on mechanical properties (UTS, Brinell hardness test), but structural parameters were changed.

3

Non-destructive metallography & replica method for inspection connecting rod material and cracks detection

Kovacevic Z., Karastojkovic Z., Aleksic V.

Production Engineering Archives

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2013

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Vol. 1, No. 1

22--24

EN

Testing of materials properties is usually a discipline for the quality assurance during manufacturing processes. In condition monitoring, certification or upgrading of existing plants and in failure analysis similar benefits from non-destructive testing of materials properties can be achieved. Another benefit from the Non-Destructive Metallography (NDM) is that the test can be made on-site. NDM is a well established and proven tool to help determine the integrity of generator and hydro turbine components during their life-cycle in power plant environments. On-site metallography of components makes it possible to evaluate the microstructure of materials. It allows microstructural analysis of large components that are difficult to move or not permitted to be destructively tested, enabling rapid evaluation of the material. Here are monitored the microstructural changes and crack detection in St 35 connecting rod steel after approximately 15 years in service. The paper includes a short description of the replica method as a technique for microstructural examination of components by using non-destructive testing method.

4

Microstructure transformation due to hydrolytic degradation of ethylene terephthalate/lactic acid copolyesters

Grzebieniak K., Ślusarczyk C., Włochowicz A., Janicki J.

Polimery

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2002

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T. 47, nr 7-8

528-533

EN

Wide-angle (WAXS) and small-angle (SAXS) X-ray scattering methods have been used to study the supermolecular structure of ethylene terephthalate and lactic acid copolyesters having different chemical structure of macromolecules. The effect of copolymers chemical structure on their microstructure was investigated using crystallized (annealed) polymer samples. It as been found that the crystalline phase in the copolyesters ontains mainly PET segments (ET sequences). The degree of rystallinity decreases with lowering the length of (ET)(x) equences ((X) over bar values). The crystallized copolymers of ufficiently long ET sequences showed lamellar structure (long eriod reflex) in SAXS studies. Copolyester specimens in form f monofilaments ("as spun" as well as annealed) were subjected o hydrolytic degradation at pH 7.35 and temp. 60degreesC over time period of up to 9 weeks. Intensity of degradation hanges (eta(red) and weight of the specimens) as well as intensity and nature of microstructure changes (WAXS and SAXS data) were highly dependent on chemical structure of the copolymers. Microstructure changes, especially SAXS characteristics, were also highly dependent on the initial morphology of the specimens, i.e. on whether they were crystallized or not before degradation.

PL

Metodami dyfrakcji promieniowania X pod dużymi (WAXS) i małymi (SAXS) kątami scharakteryzowano strukturę różniących się składem i sposobem otrzymywania próbek kopoliestrów na podstawie tereftalanu etylenu (ET) i kwasu L-mlekowego (LA) (tabela 1). Stwierdzono, że faza krystaliczna próbek kopoliestrów ET/LA krystalizowanych (wygrzewanych) w temp. 100-140"C składa się głównie z sekwencji ET. Stopień krystaliczności tych próbek oraz przeciętne wymiary krystalitów zmniejszają się ze zmniejszaniem długości sekwencji ET (wartości X) (tabela 2). Wyniki badania metodą SAXS wskazują, że kopolimery o dostatecznie długich sekwencjach ET charakteryzują się występowaniem tzw. refleksów pochodzących od wielkich okresów struktury la-melarnej (rys. 2 i 3). Próbki kopoliestrów poddawano degradacji hydrolitycznej (środowisko buforu o pH = 7,35, temp. 60°C, czas do 9 tygodni). Przebieg degradacji określano badając zmiany ciężaru, lepkości zredukowanej, stopnia krystaliczności oraz wymiarów wielkiego okresu (tabele 3-5). Intensywność tych zmian zależy od wyjściowego składu chemicznego i morfologii próbek a także od ich historii termicznej (uprzedniej krystalizacji lub jej braku).