Wyniki wyszukiwania - BazTech

1

Jak poprawić akustykę zabytkowych budynków?

Nawara Radosław, Chmielewski Marcin, Deryło Przemysław, Jarosz Mikołaj

Izolacje

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2024

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T. 29, nr 3

133--138

PL

W artykule autorzy wyjaśniają, czym jest renowacja akustyczna. Opisują, jak poprawić akustykę zabytkowych budynków oraz na jakie materiały zgodzi się konserwator zabytków. Podpowiadają, które elementy wymieniać w celu poprawy akustyki zabytku i o czym w zakresie izolacji akustycznej muszą pamiętać inwestor i zarządca zabytkowego budynku, aby skutecznie wyeliminować źródła hałasu.

EN

In the article, the authors explain the concept of acoustic renovation. They advise how to improve the acoustics in historic buildings and what materials will be accepted by the conservation officer. They suggest which elements should be replaced to improve the acoustics of the historic building and what aspects of acoustic insulation shall be considered by the investor and the administrator of the historic building in order to effectively eliminate noise sources.

2

Wyznaczanie właściwości reologicznych polimerowych kompozytów drzewnych o dużej zawartości drewna na podstawie reometrii kapilarnej. Cz. 2, Badania reometryczne

Nastaj Andrzej, Chmielewski Marcin, Buziak Kamila, Wilczyński Krzysztof

Przemysł Chemiczny

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2023

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T. 102, nr 3

295--300

PL

Przedstawiono stan wiedzy i przegląd literatury w zakresie właściwości reologicznych polimerowych kompozytów drzewnych. Poddano dyskusji zagadnienie wyznaczania właściwości reologicznych kompozytów drzewnych na podstawie reometrii kapilarnej. Wskazano na rozległe możliwości reometrii kapilarnej w zakresie wyznaczania nie tylko krzywych płynięcia i krzywych lepkości, ale także badania zjawiska poślizgu, oceny granicy płynięcia, różnic naprężeń normalnych oraz lepkości podłużnej. Poddano dyskusji zagadnienie wpływu poprawek reometrycznych Rabinowitscha, Bagleya i Mooneya na położenie krzywej lepkości względem nieskorygowanej krzywej lepkości.

EN

Rheological studies of polymer-wood composite (WPC) with polypropylene matrix contg. 50 or 70% by mass wood filler were performed. Flow and viscosity curves were detd. at 180, 190 and 200°C, and tests of longitudinal viscosity and yield stress at 190°C were carried out. The tested composites had typical pseudoplastic properties, but yield stress, slip phenomenon and stretching (longitudinal viscosity) were obsd. during the flow. The effect of Rabinowitsch, Bagley and Mooney rheometric corrections on the position of the viscosity curve in relation to the uncorrected viscosity curve was discussed.

3

A multiscale experimental analysis of mechanical properties and deformation behavior of sintered copper-silicon carbide composites enhanced by high-pressure torsion

Nosewicz Szymon, Bazarnik Piotr, Clozel Melanie, Kurpaska Łukasz, Jenczyk Piotr, Jarząbek Dariusz, Chmielewski Marcin, Romelczyk-Baishya Barbara, Lewandowska Malgorzata, Pakieła Zbigniew, Huang Yi, Langdon Terence G.

Archives of Civil and Mechanical Engineering

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2021

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Vol. 21, no. 3

776--794

EN

Experiments were conducted to investigate, within the framework of a multiscale approach, the mechanical enhancement, deformation and damage behavior of copper–silicon carbide composites (Cu–SiC) fabricated by spark plasma sintering (SPS) and the combination of SPS with high-pressure torsion (HPT). The mechanical properties of the metal–matrix composites were determined at three different length scales corresponding to the macroscopic, micro- and nanoscale. Small punch testing was employed to evaluate the strength of composites at the macroscopic scale. Detailed analysis of microstructure evolution related to SPS and HPT, sample deformation and failure of fractured specimens was conducted using scanning and transmission electron microscopy. A microstructural study revealed changes in the damage behavior for samples processed by HPT and an explanation for this behavior was provided by mechanical testing performed at the micro- and nanoscale. The strength of copper samples and the metal–ceramic interface was determined by microtensile testing and the hardness of each composite component, corresponding to the metal matrix, metal–ceramic interface, and ceramic reinforcement, was measured using nano-indentation. The results confirm the advantageous effect of large plastic deformation on the mechanical properties of Cu–SiC composites and demonstrate the impact on these separate components on the deformation and damage type.

4

Microstructure and selected properties of Ni-Cr-Re coatings deposited by means of plasma thermal spraying

Tobota Konrad, Chmielewski Marcin, Dusza Ján

Welding Technology Review

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2020

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R. 92, nr 5

15--23

EN

The article presents the results of research on plasma sprayed Ni-Cr-Re coatings. The substrate was 16Mo3 chromium-molybdenum steel used in the production of boilers. The coatings were sprayed with Oerlikon Amdry 4535 80% Ni, 20% Cr powder with 20-45μm granulation. 1% metallic rhenium was added to the base powder using a high energy ball milling method. Rhenium is a heavy, high-density metal. As an alloying addition, it improves the heat resistance of alloys, creep resistance and high temperature oxidation. Rhenium alloys are widely used in the energy and aviation industries as an alloying additive to prevent creep. Observations were made on an optical microscope and a SEM microscope. Hardness tests and optical surface testing with a profilometer were carried out.

PL

W artykule przedstawiono wyniki badań nad powłokami Ni-Cr-Re natryskiwanymi plazmowo. Podłoże stanowiła stal kotłowa chromowo-molibdenowa 16Mo3. Powłoki natryskiwano materiałem w postaci proszku Oerlikon Amdry 4535 80% Ni, 20% Cr o granulacji 20-45fμm. Do bazowego proszku dodano 1% metalicznego renu stosując metodę wysokoenergetycznego mielenia w młynie kulowym. Ren jest dodatkiem stopowym poprawiającym żarowytrzymałość stopów, odporność na pełzanie i utlenianie wysokotemperaturowe. Stopy z dodatkiem renu mają szerokie zastosowanie w przemyśle energetycznym i lotniczym. Przeprowadzono badania metalograficzne mikroskopowe, próby twardości oraz optyczne badanie powierzchni profilometrem.

5

FGM based on copper–alumina composites for brake disc applications

Strojny‑Nędza Agata, Pietrzak Katarzyna, Gili Flavia, Chmielewski Marcin

Archives of Civil and Mechanical Engineering

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2020

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Vol. 20, no. 3

279--291

EN

Copper–alumina composites of the interpenetrating networks type are interesting materials for many applications because of their properties. On the base of preliminary investigations and practical works, in order to obtain a material with high resistance to friction wear as well as good dissipation of heat generated during work, it was decided that a developed material would be prepared on the base of the Cu–Al2O3 composite, with a graded composition. In this paper, we present the developed method of manufacturing dense copper–alumina FGMs, using ceramic preform with a graded porosity infiltrated with molten copper. The article also presents the full characterization of the obtained materials and mainly the impact of microstructure on the useful properties. The produced gradient material of a Cu–Al2O3 brake disk underwent tribological tests under conditions resembling real conditions. These disks also went through a series of abrasive wear trials at different operation stages. In comparison with the reference material (i.e., grey cast iron), the obtained gradient materials are characterized by a lower degree of wear when retaining a similar coefficient of friction value due to the ceramic phase addition. Additionally, it was found that using the copper-based gradient material guarantees faster heat dissipation from the contact area.

6

Microstructure and selected properties of Ni-Cr-Re coatings deposited by means of HVOF thermal spraying

Tobota Konrad, Chmielewski Tomasz, Chmielewski Marcin

Welding Technology Review

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2019

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R. 91, nr 1

25--30

EN

The article presents selected results of testing Ni-Cr-Re coatings deposited by means of HVOF supersonic spray. The substrate made of 16Mo3 chromium molybdenum boiler steel was sprayed with a powder material of Oerlikon Amdry 4535 80% Ni, 20% Cr, 20÷45 μm, to which 1% of metallic rhenium was added using the high energy milling method in a ball mill. The Rhenium is an alloying additive that improves the heat resistance of alloys, creep and high temperature oxidation resistance. Alloys with the addition of rhenium are widely used in the aerospace industry (nickel superalloys) and in power industry. Metallographic microscopic examinations, microhardness tests and surface profilometry were carried out.

PL

W artykule przedstawiono wybrane wyniki badań powłok Ni-Gr-Re natryskiwanych naddźwiękowo. Podłoże ze stali kotłowej chromowo-molibdenowej 16Mo3 natryskiwano materiałem powłokowym w postaci proszku Oerlikon Amdry 4535 80% Ni, 20% Cr o granulacji 20÷45 μm, do którego dodano 1% metalicznego renu stosując metodę wysokoenergetycznego mielenia w młynie kulowym. Ren jest dodatkiem stopowym poprawiającym żarowytrzymałość stopów, odporność na pełzanie i utlenianie wysokotemperaturowe. Stopy z dodatkiem renu mają szerokie zastosowanie w przemyśle lotniczym (nadstopy niklu) oraz w energetyce. Przeprowadzono badania metalograficzne mikroskopowe, próby mikrotwardości oraz badanie powierzchni profilometrem optycznym.