Wyniki wyszukiwania - BazTech

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Wstępne nieniszczące badania posadzki i ścian w Pałacu Wielkich Mistrzów na zamku średnim w Malborku

Drobiec Łukasz, Kozłowska Sylwia

Przegląd Budowlany

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2024

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R. 95, nr 1-2

60--66

PL

Zamek w Malborku jest najpotężniejszą twierdzą średniowiecznej Europy. Jego niezwykłe walory historyczno-artystyczne doceniono w 1997 roku, wpisując obiekt na listę Światowego Dziedzictwa Kulturowego UNESCO. Niestety tak stary obiekt wciąż jest narażony na powstawanie uszkodzeń. Przed trzydziestoma laty konieczne było kompleksowe wzmocnienie posadowienia północno-zachodniej ściany Wielkiego Refektarza na Zamku Średnim. Obecnie zarysowania ścian i sklepień występują w południowo-wschodniej części Pałacu Wielkich Mistrzów. Wystąpienie uszkodzeń w tak unikatowym obiekcie należy traktować bardzo poważnie. W artykule opisano wyniki wstępnych nieniszczących badań posadzek piwnicznych i ścian wykonanych w rejonie uszkodzeń. Na podstawie analizy uzyskanych wyników wskazano dalsze kierunki koniecznych prac diagnostycznych.

EN

Malbork Castle is the largest castle in medieval Europe. Its extraordinary historical and artistic values were appreciated in 1997, when the castle was entered on the UNESCO World Heritage List. Unfortunately, such an old building is still vulnerable to damage. Thirty years ago, it was necessary to comprehensively strengthen the foundation of the north-western wall of the Great Refectory in the Middle Castle. Currently, the walls and vaults are scratched in the south-eastern part of the Palace of the Grand Masters. The occurrence of damage in such a unique object should be treated very seriously. The article describes the results of preliminary non-destructive tests of basements floor and wall coatings made in the area of damage. On the basis of the analysis of the obtained results, further directions of necessary diagnostic work were indicated.

2

Scanning Electron Microscopy as a Tool for Castings Quality Analysis

Jezierski Jan, Dojka M., Stawarz M., Dojka R.

Archives of Foundry Engineering

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2022

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Vol. 22, iss. 1

53--61

EN

Nowadays, the best castings’ manufacturers have to meet very demanding requirements and specifications applicable to mechanical properties and other characteristics. To fulfill those requirements, more and more sophisticated methods are being used to analyze the internal quality of castings. In many cases, the commonly used Non-Destructive Methods, like X-ray or ultrasonic testing, are not enough to ensure precise and unequivocal evaluation. Especially, when the properties of the casting only slightly fail the specification and the reasons for such failures are very subtle, thus difficult to find without the modern techniques. The paper presents some aspects of such an approach with the use of Scanning Electron Microscopy (SEM) to analyze internal defects that can critically decrease the performance of castings. The paper presents the so-called bifilm defects in ductile and chromium cast iron, near-surface corrosion caused by sulfur, micro-shrinkage located under the risers, lustrous carbon precipitates, and other microstructure features. The method used to find them, the results of their analysis, and the possible causes of the defects are presented. The conclusions prove the SEM is now a powerful tool not only for scientists but it is more and more often present in the R&D departments of the foundries.

3

Identification of Lack of Fusion and Incomplete Penetration in Butt Weld Joint by Ultrasonic Phased Array Method and X-Ray Method

Koňár R., Mičian M., Boháčik M., Gucwa M.

Archives of Metallurgy and Materials

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2019

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Vol. 64, iss. 3

1117--1124

EN

The main goal of the article is to identify artificially created defects like lack of fusion and incomplete penetration in buttweld joint using non-destructive volumetric methods. These defects are the most serious defects in welds of steel constructionsfrom the safety point of view. For identification, an ultrasonic phased array technique and a conventional X-ray using digital imaging were used. The theoretical part of the article describes the current state of the given issue and provides basic theoretical knowledge about ultrasonic and X-ray welding tests. In the experimental part, the procedure and results of testing butt weld joint are described by both non-destructive methods. The butt weld joint was made from steel S420MC. Each indication obtained by the ultrasonic and x-ray technique is supplemented by the macrostructure of the weld taken from the indication position. The results of the experimental work mentioned in the article point to the possibility and reliability of the identification of melting defects by selected nondestructive methods in terms of their character and orientation.

4

An analytical approach to prediction of internal defects during the flat rolling process of strain-hardening materials

Amjadian P., Haghighat H.

Journal of Theoretical and Applied Mechanics

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2017

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Vol. 55 nr 4

1341--1353

EN

In this paper, the upper bound method has been used in analysis of the flat rolling process and prediction of internal defects for a strain-hardening material. The arc of contact has been replaced by a chord. The inlet shear boundary of the deformation zone has been assumed as an exponential curve and the boundary at the exit has been assumed as a cylindrical surface. A kinematically admissible velocity field has been proposed and internal, shear and frictional power terms have been derived. By minimizing the total power with respect to the neutral point position and the shape of the inlet shear boundary, the rolling torque has been determined. A criterion has been presented to predict the occurrence of the internal defects for given rolling conditions. Comparison of the analytically developed approach for rolling torque and internal defects with published theoretical and experimental data shows generally good agreement.

5

Koncentracja naprężeń w jednokierunkowych materiałach kompozytowych przy jednoosiowym rozciąganiu i obecności wad wewnętrznych wypełniacza

Larin A. A., Rezniczenko W.I.

Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika

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2012

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z. 84[284], nr 2

31--37

EN

The increasing use of composite materials (CM) in the industry requires improving the quality of manufacture of products from the CM and the improvement of their control. The use of modern nondestructive testing (NDT) methods reveals defects in the internal structure of units made by the CM. To assess the influence of defects on the product properties required the development of appropriate methodologies. The theme of this paper is to analyze the increasing stresses in unidirectional composites in a state of uniaxial tension-compression in the presence of the filler.

6

Strefy nanokrystaliczne uzyskiwane w wysokoenergetycznej obróbce materiałów.

Babul T.

Inżynieria Materiałowa

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1999

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R. XX, nr 5

450-453

PL

Celem niniejszej pracy jest przedstawienie danych doświadczalnych uzyskanych podczas obróbki materiałów, w których uzyskuje się pasma amorficzne bez doprowadzenia materiału do stanu ciekłego lub gazowego. Pasma takie otrzymuje się jednak pod warunkiem doprowadzenia materiału do specyficznego stanu, nazwanego umownie wysoko wzbudzonym energetycznie. Charakteryzuje się on niestabilnym i nieuporządkowanym rozmieszczeniem atomów w przestrzeni. Powstaje w przypadku wprowadzenia energii zewnętrznej przewyższającej energię wewnętrzną w ograniczony obszar zderzających się materiałów. Stan wysoko wzbudzony energetycznie najłatwiej uzyskuje się gdy suma obciążeń powoduje jednocześnie powstanie wysokiego ciśnienia i dużego odkształcenia poślizgowego. Zgodnie z założeniem niniejszej publikacji przedstawienie problemu powstawania pasm o strukturze amorficznej na skutek działania dużych ciśnień i odkształceń poślizgowych. Odkształcenie plastyczne powoduje wzrost energii nasycenia materiału kosztem podwyższenia gęstości wewnętrznych defektów. Proces taki prowadzi do powstania nowych metastabilnych stanów, w tym struktury amorficznej, równolegle z rozdrobnieniem ziaren do ultradrobnych rozmiarów. Przytoczono prace doświadczalne opisujące powstanie tego rodzaju struktury.

EN

The aim of this work is to present the literature experimental data on amorphous bands obtained in materials that were subjected to the treatment in which there is no change in material state into liquid or gaseous one. However, such bands can be obtained only when material is brought to the specific state, so called, highly energetic one. This state is characterised by unstable and disordered configuration of atoms in space. Such a configuration occurs when external energy, exceeding internal energy, is introduced into some limited region of impacting materials. Highly energetic state is easy to obtain when the load simultaneously produces high pressure and slip deformation. Plastic deformation causes increase in saturation energy of material due to increase in density of internal defects. Such a process leads to appearance of new metastable states, including amorphous structure with simultaneous reduction of grain sizes to ultra-fine ones. The results of experimental investigations confirmed of such a structure.