Biblioteka Nauki

1

Kompleksowa analiza mikrostrukturalna i krystalograficzna stopów metali z wykorzystaniem elektronów rozproszonych wstecznie

100%

Śmieszek Z. , Woch M. , Kubica L.

Zeszyty Naukowe Politechniki Świętokrzyskiej. Mechanika

|

2000

|

tom Z. 72

165-170

PL

Przedstawiono wyniki badań mikrostrukturalnych trudno przerabialnego plastycznie stopu Cu Mn38Ni9,5 przeznaczonego do wytwarzania spoiw twardych, stosowanych do połączeń metali z częścią roboczą narzędzi (węglik spiekany, cermet). Badania mikrostrukturalne i krystalograficzne wykonano za pomocą mikroanalizatora rentegenowskiego wyposażonego w spektrometr elektronów wstecznie rozproszonych. Wyniki badań potraktowano jako przykład możliwości, które stwarza analiza widm dyfrakcyjnych elektronów wstecznie rozproszonych (tzw. metoda EBSD- Electron Backscatter Diffraction). Na przykładzie opisanych wyników badań wykazano podstawowe mozliwości spektrometru EBSD, typu OPAL, który - wraz z odpowiednim oprogramowaniem - zainstalowany jest w mikroanalizatorze rengenowskim JCXA 733, w Instytucie Metali Nieżelaznych.

EN

The results of microstructural investigations of Cu Mn38Ni9,5 alloy used for manufacturing of hard solders destined for metal/cermet (or metal/sintered carbide) binding, were performed. The investigations had been carried out by using the electron probe microanalyzer, equiped with electron backscatter diffraction system (EBSD). The results were treated as the example of possibilities which gives the analysis of electron backscatter diffraction patterns. On the basis of performed results the main options offered by OPAL spectrometer were revealed. This spectrometer and suitable software for EBSD patterns (Kikuchi patterns) analysis is installed in JCXA 733 microprobe in the Non-Ferrous Institute.

2

Statistical analysis using multiple regression of stereological parameters for skeleton castings microstructure

84%

Cholewa M. , Dziuba-Kałuża M.

Archives of Foundry Engineering

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2011

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tom Vol. 11, iss. 3 spec.

43--48

EN

In this article authors showed influence of technological parameters and modification treatment on structural properties for closed skeleton castings. Approach obtained maximal refinement of structure and minimal structure diversification. Skeleton castings were manufactured in accordance with elaborated production technology. Experimental castings were manufactured in variables technological conditions: range of pouring temperature 953÷1013 K , temperature of mould 293÷373 K and height of gating system above casting level 105÷175 mm. Analysis of metallographic specimens and quantitative analysis of silicon crystals and secondary dendrite-arm spacing analysis of solution α were performed. Average values of stereological parameters for all castings were determined. (B/L) and (P/A) factors were determined. On basis results of microstructural analysis authors compares research of samples. The aim of analysis was selected samples on least diversification of refinement degree of structure and least silicon crystals. On basis microstructural analysis authors state that samples 5 (AlSi11, Tpour 1013K, Tmould 333K, h – 265 mm) has the best structural properties (least diversification of refinement degree of structure and the least refinement of silicon crystals). Then statistical analysis results of structural analysis was obtained. On basis statistical analysis autors state that the best structural properties for technological parameters: Tpour = 1013 K, Tmould = 373 K and h = 230 mm [4]. The results of statistical analysis are the prerequisite for optimization studies.

3

Analysis of the Austenite Grain Growth in Low-Alloy Boron Steel with High Resistance to Abrasive Wear

84%

Białobrzeska B. , Dudziński W.

Archives of Metallurgy and Materials

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2015

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tom Vol. 60, iss. 3A

1649--1655

EN

Today low-alloy steels with boron achieve high resistance to abrasive wear and high strength. These features are obtained by using advanced technology of manufacturing. This makes boron steels increasingly popular and their application more diverse. Application of these steels can extend the lifetime of very expensive machine construction in many industries such as mining, the automotive, and agriculture industries. An interesting subgroup of these materials is steel with boron intended for heat treatment. These steels are supplied by the manufacturer after cold or hot rolling so that it is possible for them to be heat treated in a suitable manner by the purchaser for its specific application. Very important factor that determines the mechanical properties of final product is austenite grain growth occurring during hot working process such us quenching or hot rolling. Investigation of the effect of heating temperature and holding time on the austenite grain size is necessary to understand the growth behavior under different conditions. This article presents the result of investigation of austenite grain growth in selected low-allow boron steel with high resistance to abrasive wear and attempts to describe the influence of chemical composition on this process.

PL

Obecnie stale z dodatkiem boru osiągają dużą odporność na zużycie ścierne w połączeniu z wysokimi parametrami wytrzymałościowymi. Te właściwości uzyskiwane są drogą zaawansowanej technologii wytwarzania. To sprawia, że stale z borem zyskują coraz większą popularność, a ich zastosowanie jest coraz szersze. Zastosowanie tego typu stali może wydłużyć trwałość często drogich maszyn przemysłu górniczego, motoryzacyjnego, czy rolniczego. Interesującą podgrupę tych materiałów stanowią stale z dodatkiem boru przeznaczone do obróbki cieplnej. Producenci dostarczają je w stanie po walcowaniu na gorąco do ewentualnie przeprowadzenia obróbki cieplnej przez kupującego odpowiedniej do konkretnego zastosowania. Ważnym czynnikiem, który istotnie wpływa na właściwości mechaniczne gotowego wyrobu, jest wielkość ziarna austenitu podczas przeprowadzania procesów obróbki cieplnej lub cieplno-plastycznej takich jak hartowanie, czy walcowanie na gorąco. A zatem określenie wpływu temperatury i czasu austenityzowania na wielkość ziarna austenitu jest bardzo istotne. W artykule przedstawiono wyniki badań rozrostu ziarna austenitu przy różnych temperaturach i czasach austenityzowania w wybranej niskostopowej stali z borem o podwyższonej odporności na ścieranie oraz podjęto próbę opisania wpływu składu chemicznego na ten proces.

4

Improving crack resistivity in Al alloy pressure vessels by FSW

84%

Lenin A. W. A. , Nagaraj P. , Lincy G.

Journal of Achievements in Materials and Manufacturing Engineering

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2016

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tom Vol. 79, nr 2

54--58

EN

Purpose: Fuel or oil transmission pipelines are made with light metal alloys to prevent corrosion and to provide a better safety record. This is achieved by the combination of perfect design, selection of materials and functioning practices. However, like any engineering structure, these lines also fail occasionally. Major cases of such failure it induces due to external interference or corrosion or due to manufacturing defects; so such of defects if they were detected before failure and that can be treated to avoid failure or the life time can be improved. Design/methodology/approach: In this study an aluminum alloy sample with micro crack was treated with FSW process with ZN powder. And studies were carried out against both treated and untreated samples with cracks. Findings: From the studies it is clear that FSW treatment over surfaces will reduces the crack initiation in light metal alloy structures. The process can be done before or after installation. Research limitations/implications: The results were recorded and suggested FSW as a best process for crack treatment in Al alloys. Especially in pressure lines or pressure vessels. Originality/value: Friction stir welding (FSW) is a solid-state metal joining process. This is energy efficient, ecofriendly, and versatile light metal joining technique. In particular, high-strength aerospace aluminum alloys can be welded by using this technique. This will produces high harden joints in light metals as just like conventional arc welding techniques. It is considered as the most significant research development in light metal joining.

5

Analysis of the OCHN3MFA steel in terms of cutting forces and cutting material flank wear mechanisms in hard turning processes

84%

Majerík J. , Barényi I. , Pokorný Z. , Sedlák J. , Neumann V. , David D. , Jaroš A. , Krbata M. , Jambor J. , Kusenda R. , Sagan M. , Procházka J.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2021

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tom Vol. 69, nr 6

art. no. e139203

EN

This article deals with the effect of selected machining parameter values in hard turning of tested OCHN3MFA steel in terms of SEM microstructural analysis of workpiece material, cutting forces, long-term tests, and SEM observations of flank wear VB and crater wear KT of used changeable coated cemented carbide cutting inserts in the processes of performed experiments. OCHN3MFA steel was selected as an experimental (workpiece) material. The selected experimental steel was analyzed prior to hard turning tests to check the initial microstructure of bulk material and subsurface microstructure after hard turning and chemical composition. Study of workpiece material’s microstructure and worn cemented carbide cutting inserts was performed with Tescan Vega TS 5135 scanning electron microscope (SEM) with the X-Ray microanalyzer Noran Six/300. The chemical composition of workpiece material was analyzed with Tasman Q4 surface analyzer. All hard turning experiments of the used specimens were performed under the selected machining parameters in the SU 50A machine tool with the 8th selected individual geometry of coated cementite carbide cutting inserts clamped in the appropriate DCLNR 2525M12-M type of cutting tool holder. During the hard turning technological process of the individual tested samples made of OCHN3MFA steel, cutting forces were measured with a Kistler 9257B piezoelectric dynamometer, with their subsequent evaluation using Dynoware software. After the long-term testing, other experiments and results were also realized, evaluating the influence of selected machining parameters with different cutting insert geometry on the achieved surface quality.

6

Preliminary Investigations of Structure and Properties of TIG Welded Ti-6Al-4V Alloy

84%

Dewangan S. , Ranjan R. , Chattopadhyaya S. , Gope D. , Bogdan-Chudy M.

Advances in Science and Technology. Research Journal

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2021

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tom Vol. 15, no 1

156--165

EN

The titanium (Ti) and its alloys are taken into interest for commercial purpose due to its low density, high yield strength and high corrosion resistance properties. The present work deals with microstructural observation and mechanical property analysis of tungsten inert gas (TIG) welded Ti-6Al-4V alloy joints. For the purpose, two different set of plates were welded at same current and voltage, i.e., 190 A and 24 V, by the TIG welding technique. A critical analysis of the microstructure and mechanical properties like tensile strength and hardness of the welded Ti-6Al-4V plates was carried out in this work. It was found that both plates showed different behavior during the tension test. Plate 1 had 464.54 MPa of tensile stress and it broke at the welded joint. Plate 2 was unaffected at the welded zone but was broken at the base metal zone. The second plate had tensile strength of 501.83 MPa. According to the hardness test, both the welded plates possessed the highest hardness at the welded zone. However, plate 2 showed approximately 10% higher hardness than that of plate 2. A proper inter-relationship was observed between the mechanical behavior and microstructural appearance. The microscopic view of the welded joints revealed the presence of α, β and martensitic-α phases.

7

Mikrostrukturalna analiza przetopionych plazmowo warstw: Cr3C2 + AlNi + Stal.

84%

Skura M. , Iwaszko J.

Rudy i Metale Nieżelazne

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1998

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tom R. 43, nr 10

522-526

PL

Prezentowana praca dotyczy wpływu przetapiania plazmowego na strukturę i własności stali 45, natryskiwanej plazmowo warstwą węglików Cr3C2 z podkładową warstwą AlNi. Analizowano morfologię i dyspersję faz warstwy wierzchniej po szybkiej krystalizacji.

EN

The paper deals with structural effects of the plasma fusion welding of plasma-sprayed carbide layer Cr3C2 with a base layer of AINi on steel 45. The morphology and dispersion of the upper layer phases after fast crystalization were analysed.

8

Toughness of HSLA-100 copper treated steels.

84%

Pytel S. M. , Garcia C. I. , DeArdo A. J.

Inżynieria Materiałowa

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1998

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tom R. XIX, nr 3

179-184

EN

The mechanical properties of a series of HSLA-100 copper treated steels with different carbon and rare earth metals (REM) contents were evaluated. The steels used in this study were heat treated to exhibit yield strengths (YS) in the range 670 to 860 MPa. Of particular interest in this study were the effect of C and REM contents on the CTOD fracture toughness, upper shelf energy(USE) and fracture appearance transition temperature (FATT) of the steels. The results obtained clearly showed the deterioration of the impact and fracture toughness properties of the steels tested as the carbon content increased. Similar effect was observed with the total inclusion projected lengh per unit area.

9

Płyty azbestowo-cementowe - badania mikrostrukturalne włókien azbestu

84%

Iwaszko J.

Prace Naukowe Akademii im. Jana Długosza w Częstochowie. Technika, Informatyka, Inżynieria Bezpieczeństwa

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2016

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tom T. 4

215--224

PL

W pracy podjęto się analizy materiałoznawczej włókien azbestu występujących w płytach azbestowo-cementowych. Do zobrazowania mikrostruktury włókien wykorzystano mikroskopię optyczną i skaningową mikroskopię elektronową. W oparciu o badania mikrostrukturalne dokonano oceny zagrożeń dla życia i zdrowia człowieka, wynikających z eksploatacji eternitu. Badaniom mikrostrukturalnym poddano ponadto płyty azbestowo-cementowe po obróbce termicznej. Badania te miały na celu zobrazowanie ewentualnych zmian w strukturze płyty oraz występujących w nich włókien azbestu, jakie mogą wystąpić w wyniku oddziaływania wysokiej temperatury, w tym także otwartego ognia np. w trakcie pożaru. Naświetlono ponadto aktualną sytuację w zakresie eliminowania zagrożeń, wynikających z użytkowania wyrobów zawierających azbest i przedstawiono metody utylizacji tego typu wyrobów.

EN

In this study, the material science analysis of asbestos fibres present in asbestos-cement panels was undertaken. To illustrate the microstructure of asbestos fibres, both optical and scanning electron microscopy was used. Based on the microstructural analysis, the risk to human life and health resulting from the use of eternit was assessed. In addition, structural investigations were carried out for asbestos-cement panels, subjected to thermal treatment. These investigations were aimed at illustrating the possible changes in panel microstructure and the asbestos fibres present within, which can come about as the result of the effect of a high temperature, including from a naked flame, e.g. during a fire. In addition, the current situation in the removal of risk resulting from the use of products containing asbestos fibres was made clear and methods of recycling such products were presented.

10

Experimental and analytical study of steel–PVA hybrid fiber-reinforced mortar containing CaCO3 whiskers subjected to freeze–thaw cycles

84%

Liu Z. , Cao M. , Xie C.

Archives of Civil and Mechanical Engineering

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2022

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tom Vol. 22, no. 4

art. no. e190, 2022

EN

In high latitude and altitude areas, cement-based composite is subject to freeze–thaw cycles. The uniaxial compressive properties and microstructure of steel–PVA fiber reinforced cement mortar incorporating CaCO3 whiskers (SPFRC-CW) before and after freeze–thaw cycles were studied in this paper. The relative mass loss (RML), relative ultrasonic pulse velocity (RUPV), and the stress–strain relationship of frost–damaged SPFRC-CW was measured for a study of the durability and mechanical property degradation rules. A damage model was established considering the freeze–thaw cycles and CW volume fraction for SPFRC-CW, which demonstrated decent consistency between theoretical and experimental curves. The microstructure was analyzed using an optical microscope (OM), scanning electron microscope (SEM), vacuum epoxy impregnation (VEI), and mercury intrusion porosimetry (MIP). The results suggest that the physical and mechanical properties of SPFRC-CW decreased with prolonged freeze–thaw cycles. The better frost resistance of SPFRC was related to the improved pore structure because of the presence of CW, as per the results of VEI and MIP.

11

Wpływ domieszki zawierającej nanometryczne zarodki fazy C-S-H na właściwości betonów popiołowych poddanych obciążeniom w pierwszych 7 dniach dojrzewania

67%

Szostak B. , Golewski G. L.

Przegląd Budowlany

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2020

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tom R. 91, nr 6

44--47

PL

Ze względu na aspekt ekologiczny oraz ekonomiczny do betonów coraz częściej stosuje się dodatki optymalizujące użycie cementu, np. w postaci popiołów lotnych (FA). Problemem takiego rozwiązania jest negatywny wpływ FA na wczesne właściwości kompozytu. Autorzy publikacji przeprowadzili badania betonów popiołowych z nanodmieszką C-S-H przyspieszającą przyrost wczesnej wytrzymałości betonu. Dodatkowo przeprowadzono badania mikrostruktury analizowanych materiałów.

EN

According to the ecological and economic aspects, more and more often cement in concrete is replaced with fly ash (FA). The problem with such a solution is the negative impact of FA on the strength properties of early age concrete. The authors of the publication have carried out tests of fly ash concrete with C-S-H nano admixture accelerating early concrete strength.

12

Wpływ łącznego dodatku mikrokrzemionki zagęszczonej i krzemionkowych popiołów lotnych na wielkość uszkodzeń w warstwie stykowej kruszywo-zaczyn

67%

Gil D. M. , Golewski G. L.

Przegląd Budowlany

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2019

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tom R. 90, nr 7-8

61--65

PL

Celem artykułu jest wykazanie, na podstawie badań własnych, czy zastosowanie do produkcji betonu odpadów przemysłowych, tj. krzemionkowych popiołów lotnych (FA ) i mikrokrzemionki zagęszczonej (SF), wpływa korzystnie na szerokość rozwarcia mikrorys przy styku kruszywa grubego i zaczynu cementowego. W pracy przedstawiono rezultaty analizy mikrostrukturalnej, przy użyciu skaningowego mikroskopu elektronowego (SEM), betonu z hybrydowymi dodatkami w postaci FA oraz SF. Na podstawie wyników badań eksperymentalnych dowiedziono, że synergia oddziaływania obu dodatków mineralnych na strukturę kompozytu betonowego pozwala na zmniejszenie rozwarcia mikrorys pomiędzy kruszywem grubym a matrycą cementową. Dodatkowo zmniejszenie szerokości mikrorys w warstwie stykowej, poprzez zastosowanie dodatków mineralnych, zwiększa trwałość betonu.

EN

The aim of the article is to prove, on the basis of own research, whether the use of industrial waste for the production of concrete, ie: siliceous fly ash (FA ) and compacted silica fume (SF), is justified in terms of economics and ecology. The paper presents the results of microstructural analysis with Scanning Electron Microscope (SEM) of concrete with the use of hybrid additives FA and SF. Based on the results from a wide range of experimental studies, it has been proved that synergy of interaction of both mineral additives on the structure of a concrete composite allows to reduce the microcracks between the coarse aggregate and the cement matrix. The reduction of the microcraks in the contact layer, by using mineral additives, effects the increase of concrete durability.