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1

Enhancing microstructural and thermal properties of TiNiPd shape memory alloys through copper addition

Hussain Abid, Khan Afzal, Khan Muhammad Imran, Ur Rehman Saif

Advances in Materials Science

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2025

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Vol. 25, nr 1(83)

66--81

EN

This study explores how the addition of copper (Cu) addition impacts the microstructural and thermal properties of shape memory alloys (SMAs), specifically TiNiPd alloys. Two compositions, 0Cu and 10Cu, were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), Optical Microscopy (OM) and differential scanning calorimetry (DSC). SEM revealed second-phase precipitates distributed along grain boundaries in both alloys, with sizes ranging from 0.9 to 2.9 μm; however, Cu addition reduced precipitate density without affecting size. The grain size increased significantly from 12.5 μm in 0Cu to 17.5 μm in 10Cu, attributed to decreased nickel content and reduced pinning effects of precipitates. Aging at 600°C and 700°C further influenced precipitate behavior and transformation temperatures, with Cu-containing alloys demonstrating enhanced thermal characteristics. DSC analysis indicated significant increases in transformation temperatures and decreased thermal hysteresis with Cu addition. These results highlight the promise of Cu as a viable substitute for Ni in enhancing the properties of TiNiPd SMAs.

2

Structure and Properties of the Nitrided Layer with Sulfides

Kazimierski Grzegorz, Stodolny Jerzy, Lewandowski Albert, Wróbel Rafał J.

Tribologia

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2024

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nr 1

57--66

EN

This study contains a brief overview of sulfur nitriding methods, i.e. a modified version of nitriding. This information is accompanied by the results of our own tests of nitrided and sulfur-nitrided coatings with the addition of MoS2 in the scope of structure assessment by means of a scanning microscope – SEM/EDS and the results of tribological tests performed under dry friction conditions on the T-05 apparatus for four variants of thermo-chemical treatment. In tribological tests, the degree of wear was observed by measuring the weight loss of both samples and counter-samples, and the beneficial effect of sulfides on reducing wear was indicated, with the sulfur nitriding variant with MoS2 added being the most advantageous. In this case, the lowest degree of wear was found for the friction pair with a sulfur-nitrogen coating reinforced with MoS2, which may lead to extending the operating time.

PL

Opracowanie zawiera krótki przegląd metod azotonasiarczania tj. zmodyfikowanej wersji azotowania. Do tych informacji dołączono wyniki własnych badań powłok azotowanych i azotonasiarczanych z dodatkiem MoS2 w zakresie obejmującym ocenę struktury za pomocą mikroskopu skaningowego – SEM/EDS i wyniki testów tribologicznych wykonanych w warunkach tarcia suchego na aparacie T-05 dla czterech wariantów obróbki cieplno-chemicznej. W testach tribologicznych obserwowano stopień zużycia przez pomiar ubytku wagi zarówno próbek, jak i przeciwpróbek, a także wskazano na korzystny wpływ siarczków na zmniejszenie zużycia, przy czym najkorzystniejszy okazał się wariant azotonasiarczania z dodatkiem MoS2. W tym przypadku stwierdzono najmniejszy stopień zużycia, co dla pary ciernej z powłoką azotonasiarczaną wzmocnioną dodatkiem MoS2 oznacza możliwość wydłużenia czasu eksploatacji.

3

Effect of Heat Treatment on Abrasion Wear Resistance of Steel with Micro-Additives of Boron and Vanadium

Białobrzeska Beata, Konat Łukasz

Tribologia

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2024

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nr 1

7--19

EN

This paper presents the results of own research regarding the role of microstructure and mechanical properties in the abrasive wear of metallic materials, demonstrated on the example of low-alloyed steel with microadditives of boron and vanadium. The first section discusses the current knowledge relating to the influence of microstructure and hardness on tribological conditions of materials. Further sections present the results of microstructure observations performed with light microscopy as well as with scanning electron microscopy and transmission electron microscopy. This research has focused on the material both in the as-delivered condition (directly after casting) and after heat treatment, which involved quenching and tempering at three temperatures: 200, 400, and 600°C. The tribological tests were performed with the use of the T-07 tribometer, in the presence of loose #90 electro corundum abrasive particles. The test results have been discussed and an attempt has been made to correlate them with the microstructure and selected mechanical properties. In order to identify wear mechanisms, the surfaces were visually inspected after the abrasion process. The inspection results indicate that the main wear mechanisms were microcutting and microploughing.

PL

W pracy zreferowano wyniki badań własnych w zakresie roli mikrostruktury i właściwości mechanicznych w zużywaniu ściernym materiałów metalicznych na przykładzie niskostopowego staliwa z mikrododatkami boru i wanadu. W początkowej części omówiono stan wiedzy dotyczący wpływu mikrostruktury i twardości na właściwości tribologiczne materiałów. Następnie przedstawiono wyniki obserwacji mikrostrukturalnych przeprowadzonych za pomocą mikroskopii świetlnej oraz elektronowej mikroskopii skaningowej. W referowanych badaniach skupiono się na materiale w stanie dostarczenia (bezpośrednio po odlewaniu) oraz na stanie obrobionym cieplnie, obejmującym hartowanie i odpuszczanie w trzech temperaturach, tj. 200, 400 i 600°C. Badania tribologiczne zostały przeprowadzone za pomocą testera T-07 w obecności luźnego ścierniwa, które stanowił elektrokorund #90. Wyniki badań zostały dodatkowe poszerzone o dyskusję oraz próbę ich korelacji z mikrostrukturą i wybranymi własnościami mechanicznymi. W celu ustalenia mechanizmów zużywania, dokonano obserwacji powierzchni po ścieraniu. Na tej podstawie stwierdzono, że głównymi mechanizmami zużycia były mikroskrawanie i mikrobruzdowanie.

4

Abrasion Wear Resistance of Welded Joints Between Hardox Steel 400 and Grade A Ship Steel

Konat Łukasz, Białobrzeska Beata

Tribologia

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2024

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nr 4

23--42

EN

This paper presents the technological and microstructural aspects of the formation and heat treatment of a welded joint between two types of steel having significantly different chemical and mechanical properties, i.e. between low-alloy high-strength, abrasion wear resistant Hardox 400 steel and grade A marine construction steel. The test results indicate that connecting the two types of steel by welding leads to the formation of a heat-affected zone in the entire welded joint area with hardness levels reduced to approximately 170–180 HV. This zone shows various microstructural changes which prevent a reliable evaluation of the abrasion wear resistance of the welded joint. Therefore, the article proposes an optimal technology of welding the two steel types, and welding technological parameters of the thermal post-treatment that allow the formation of microstructures having an increased–in comparison to the pre-welding condition–resistance to abrasion wear processes, as measured with the electro corundum #90 abrasive particles. Heat treatment optimized the microstructure, improving the abrasion wear resistance by 16% compared to the as-welded condition.

PL

W pracy przedstawiono technologiczne i mikrostrukturalne aspekty wykonywania i obróbki cieplnej połączenia spawanego dwóch stali o bardzo odmiennych właściwościach chemicznych i mechanicznych, tj. niskostopowej, wysokowytrzymałej stali odpornej na zużywanie ścierne Hardox 400 ze stalą konstrukcyjną, predefiniowaną do zastosowań w przemyśle okrętowym kategorii A. W wyniku przeprowadzonych badań stwierdzono, że zastosowanie do łączenia tych stali procesów spawalniczych prowadzi do powstawania w obrębie całego połączenia spawanego szerokiej strefy wpływu ciepła o twardości 170-180 HV, charakteryzującej się zróżnicowanymi zmianami mikrostrukturalnymi, uniemożliwiającymi miarodajną ocenę odporności na zużywanie ścierne wykonanego połączenia. W związku z tym zaproponowano optymalną technologię spawania obu stali oraz warunki i parametry postobróbki cieplnej, prowadzących do uzyskania w strefie połączenia spawanego mikrostruktur odznaczających się podwyższoną – w stosunku do stanu bezpośrednio po spawaniu – odpornością na procesy zużycia ściernego, wyznaczoną odziaływaniem luźnego ścierniwa, tj. elektrokorundu 90. Przeprowadzona obróbka cieplna spowodowała zmiany właściwości mikrostrukturalnych, co przełożyło się na wzrost odporności na zużywanie ścierne o 16% w porównaniu ze stanem po spawaniu.

5

Making glass flatness a standard

Lohrer Diana, Martinez Juan Pablo

Świat Szkła

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2024

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R. 29, nr 1

1--4

6

The study of porosity in a356 secondary aluminium alloys with higher iron content

Šurdová Zuzana, Tillová Eva, Kuchariková Lenka, Mikolajčík Martin

System Safety : Human - Technical Facility - Environment

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2024

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Vol. 6, iss. 1

430--438

EN

The production of secondary (recycled) aluminium has gained significant importance in recent years, driven by the need to reduce electricity consumption and waste associated with primary aluminium production. Secondary aluminium alloys thus play a vital role in sustainable industrial practices, particularly within sectors such as automotive, aerospace and marine. Recently, these alloys have gained traction in electric vehicle components manufacturing, where lightweight and sustainable materials are critical to enhancing energy efficiency and extending vehicle range. However, secondary aluminium alloys are prone to impurities and casting defects, notably porosity, which presents challenges in achieving optimal mechanical properties and surface quality. Porosity reduces corrosion resistance, fatigue, and tensile strength, thus impacting overall material performance. This porosity can be categorised by size (microporosity and macroporosity) and origin, with gas and shrinkage porosity being the primary types. This study examined experimental A356 secondary aluminium alloys with varying iron contents in as-cast and T6 heat-treated conditions. The analysis focused on the quantitative assessment of casting defects within the microstructure, specifically, the types of pores present, the area percentage of pores, and average pore size. These insights contribute to a deeper understanding of how casting defects impact the performance of recycled aluminium alloys in sustainable applications, particularly in the context of nextgeneration electric vehicles.

7

Mechanical properties of chromium steel drills in the context of durability and safety of use

Bałaga Zbigniew, Opydo Michał, Dudek Agata, Lisiecka Barbara

System Safety : Human - Technical Facility - Environment

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2024

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Vol. 6, iss. 1

311--319

EN

This article presents the research results on the influence of heat treatment of chromium steel, used in the production of drill bits, on their mechanical properties and operational safety. The analyses revealed that the steel used in manufacturing the studied drill bit underwent hardening and tempering processes, which affected its structure and hardness. The presence of tempered martensite and manganese sulfides was observed, which, although not having a destructive impact on the steel's properties, may limit the formation of undesirable iron sulfides. Additionally, a layer with reduced hardness was identified on the working surface of the drill bit, suggesting the possibility of tool overheating during operation. During the tool's use, complex mechanical stresses, such as torsional, compressive, and bending stresses, may accumulate in areas prone to damage, especially at the interface between the tooth and the drill bit shank. The article emphasizes the importance of proper tool usage, including adjusting pressure and drilling angle and maintaining optimal operational conditions to ensure safety and durability. The research findings aim to enhance workplace safety and improve the performance of cutting tools in materials engineering.

8

Analiza możliwości stosowania uzdatnionego pyłu z recyklingu betonu jako składnika głównego cementu

Dobiszewska Magdalena, Lasek Bogusław

Przegląd Budowlany

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2024

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R. 95, nr 6

113--116

PL

Podczas produkcji kruszywa recyklingowego z gruzu betonowego powstają duże ilości odpadu w postaci drobnej frakcji (Recycled Concrete Fines – RCF). Materiał ten stosowany może być jako dodatek mineralny do cementu lub betonu. Jednak z uwagi na małą reaktywność i dużą porowatość może wpływać negatywnie na właściwości technologiczne mieszanki betonowej oraz parametry stwardniałego betonu. Uzdatnienie RCF w wyniku obróbki termicznej (kalcynacji) i mineralnej karbonatyzacji wpływa na poprawę właściwości chemicznych i fizycznych odpadu oraz zwiększenie jego reaktywności. Pozwala to na bardziej efektywne wykorzystanie tego materiału w produkcji kompozytów cementowych.

EN

During the production of recycled aggregate from demolition concrete, large amounts of waste are generated in the form of Recycled Concrete Fines (RCF). This material can be used as a mineral additive to cement or concrete. However, due to its low reactivity and high porosity, it may have a negative impact on the technological properties of the mixture and the parameters of the hardened concrete. RCF pre-treatment as a result of thermal activation (calcination) and mineral carbonation improves the chemical and physical properties of the waste and increases its reactivity. This allows for more effective use of this material in the production of cement composites.

9

Transformations of diatomite components and changes in its technical properties caused by calcination at different temperatures - a case study of the Jawornik deposit, Poland

Figarska-Warchoł Beata, Rembiś Marek

Gospodarka Surowcami Mineralnymi

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2024

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T. 40, z. 4

21--46

EN

Diatomite rocks from the eastern part of the Polish outer Carpathians come in several varieties with different colour, compactness, amount of clay and sandy substance as well as the degree of silicification. One of them is dark grey blocky diatomite, present in the Jawornik deposit and characterised by average quality. During the tests, it was thermally calcined at temperatures from 300°C to 1,200°C in order to improve its functional properties. The results of observations regarding the changes that the rock and its components underwent under conditions of increasing temperature were presented. The results of thermal analysis, X-ray diffraction and tests of physical properties (i.e. density, water absorption and Vickers microhardness) of the rock were presented. Detailed observations of the rock’s mineral components were made using a scanning microscope. Their physical changes (e.g. cracks or signs of melting) and chemical transformations were described. It has been shown that during calcination, irreversible changes occur in the mineral composition and structure of diatomite. It was proven that for the discussed diatomite the optimal calcination temperature is 900°C, as it ensures the greatest increase in its open porosity by 11% and an almost threefold increase in its hardness. The chemical composition of diatomite also changes due to the combustion of the organic matter present in it and the resulting relative increase in the 1,200 content. Calcination improves the technological features of this variety of diatomite, making it similar to the best quality varieties found in this deposit.

PL

Skały diatomitowe pochodzące ze wschodniej części polskich Karpat zewnętrznych występują w kilku odmianach o różnej barwie, zwięzłości, stopniu zailenia, zapiaszczenia i skrzemionkowania. Jedną z nich jest ciemnoszary diatomit o blocznym rozpadzie, powszechnie występujący w złożu Jawornik i reprezentujący tu surowiec o przeciętnej jakości. W trakcie badań został on poddany termicznej kalcynacji w temperaturach od 300 do 1200°C w celu poprawy jego właściwości użytkowych. Przedstawiono wyniki obserwacji i badań dotyczących zmian, jakim ulegała skała i jej składniki w warunkach wzrastającej temperatury. Zaprezentowano wyniki analizy termicznej, dyfrakcji rentgenowskiej i badań właściwości fizycznych (tj. gęstość, nasiąkliwość wodna czy mikrotwardość Vickersa) skały. Przeprowadzono szczegółowe obserwacje w mikroskopie skaningowym składników mineralnych skały. Opisano ich fizyczne zmiany (np. spękania czy oznaki nadtopienie) oraz chemiczne przeobrażenia. Wykazano, że podczas kalcynacji doszło do nieodwracalnych zmian w składzie mineralnym i strukturze diatomitu. Dowiedziono, że dla omawianego diatomitu optymalna temperatura kalcynacji wynosi 900°C, gdyż zapewnia ona największy wzrost jego porowatości o 11% i prawie trzykrotny wzrost jego twardości. Zmianie ulega także skład chemiczny diatomitu na skutek spalenia występującej w nim materii organicznej i wynikającego stąd względnego wzrostu zawartości 1200. Kalcynacja doprowadza do poprawy cech technologicznych tej odmiany diatomitu, upodabniając go do najlepszych jakościowo odmian występujących w złożu.

10

Obróbka cieplna w procesie kwalifikowania technologii spawania łukowego stali

Makówka Arkadiusz

Fastener : rynek elementów złącznych

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2024

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nr 1

21--27

PL

Artykuł opisuje jedno ze szczególnych zagadnień związanych z kwalifikowaniem technologii - obróbkę cieplną po spawaniu, w szczególności w aspekcie wymagań dodatkowych opisanych w normach dotyczących różnych zastosowań (normach wyrobów), uznanych specyfikacjach technicznych oraz raporcie technicznym ISO/TR 14745.

11

Rework and repair of steam turbine components subject to flexible operation

Biesinger Frank, Huáscar Lorini, Banaszkiewicz Mariusz

Energetyka

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2024

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nr 12

520--524

EN

The increase in renewable energy penetration on the grid has accelerated the need to transition conventional fossil-based energy sources from their traditional base load operation to more flexible operational regimes. The mode of operation changed dramatically in terms of number of starts, operating hours per annum, and variation in load level. This results in greater thermal transients on operational equipment leading to an increase in low cycle fatigue damage. To ensure the continued integrity of the steam turbine components, it is essential to assess the lifetime status by applying residual lifetime analysis methods. Depending on the amount of lifetime consumption and the extent of potential crack findings, different component repair options are possible. The rework or repair options can be divided into two main groups, namely cold and hot rework. These two options can also be carried out consecutively. All rework or repair options provide the opportunity to improve the application of a component by applying profiling with improved stress fields and even superior materials, in the case of hot rework. The aim of the rework/reconditioning is to ensure that the steam turbine component is suitable for future operation. This ensures that plants are well placed to deliver more flexible operation in the energy industry through careful tailored refurbishments and reworks.

PL

Wzrost znaczenia energii odnawialnych w sieciach energetycznych przyspieszył potrzebę przejścia konwencjonalnych źródeł energii bazujących na paliw kopalnych z tradycyjnej pracy w podstawie na bardziej elastyczne reżimy pracy. Warunki eksploatacji uległy drastycznej zmianie w zakresie liczby uruchomi rocznych godzin pracy oraz zakresu zmian mocy. Skutkuje to występowaniem zwiększonych obciążeń termicznych elementów prowadzących do wzro zużycia z tytułu zmęczenia niskocyklowego. W celu zapewnienia dalszej wytrzymałości elementów turbin parowych podstawową kwestią staje się ocena sti żywotności z zastosowaniem metod analizy trwałości resztkowej. W zależności od poziomu wyczerpania żywotności i zakresu potencjalnego występowe pęknięć możliwe są różne opcje naprawy elementów. Obróbki i naprawy można generalnie podzielić na dwie grupy: naprawy na zimno i naprawy na gors, Te operacje mogą być również wykonywane kolejno jedna po drugiej. Obie opcje dają możliwość poprawy własności użytkowych elementów pope zastosowanie zoptymalizowanych kształtów poprawiających rozkład naprężeń, a nawet użycie lepszych materiałów w przypadku napraw na gorąco. Cel proponowanych obróbek i napraw jest zapewnienie przydatności elementów turbin parowych do dalszej eksploatacji. Umożliwia to elektrowniom oferowa rynkom energii bardziej elastycznej eksploatacji właśnie dzięki wykonaniu starannie dobranych obróbek i napraw.

12

Friction wear resistance of 42CrMo4 surface layer after low-pressure ferritic nitrocarburising (FNC)

Pawęta S., Pietrasik R., Wołowiec-Korecka E.

Archives of Materials Science and Engineering

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2024

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Vol. 129, nr 1

24--30

EN

Purpose: The work aimed to assess the performance properties of layers produced using the low-pressure ferritic nitrocarburising technology, in particular wear resistance under friction conditions. The assessment has been made in relation to analogous elements subjected only to heat treatment (hardening with tempering). Design/methodology/approach: The material for the tests consisted of two groups of friction pairs (5 friction pairs in each group) made of 42CrMo4 steel. The 42CrMo4 steel has been heat-treated (hardening at 880°C in oil, tempering at 570°C for 2 hours). Half of the samples have been subjected to low-pressure ferritic nitrocarburising at 560°C for 6 hours. The friction test has been conducted according to the PN-75/M-04308 standard for 2 minutes at a load of 445 N. Findings: The test results showed that the elements after ferritic nitrocarburising had almost twice the surface hardness (662 HV1) than the control group (339 HV1). The average weight wear of the heat-treated and ferritic nitrocarburised elements has been 0.011 g, with an average wear in the control group of 1.022 g. The average friction coefficient in the heat-treated and ferritic nitrocarburised friction pairs was 0.188, while in the heat-treated only pairs, it was 0.358. The Man-Whitney U test has shown that the differences between the average weight wear and the average friction coefficient values are significant (p<0.05). Research limitations/implications: The paper investigates the effect of low-pressure ferritic nitrocarburising technology on the surface layer of steel materials. Practical implications: Low-pressure ferritic nitrocarburising technology shows the potential for practical applications in industrial reality at a level at least equivalent to those currently used worldwide. Originality/value: It is the first known publication on the effect of low-pressure ferritic nitrocarburising technology on the performance properties of the surface layer of elements improved by this method.

13

Study on Preparation Technology and Heat Conduction Mechanism of High-Purity & Ultra-Fine Alumina Powder from Scrap Aluminum Cans

Wang Chengmin, Politov Anatoly, Wang Xiuhui, Yang Jinlong

Archives of Foundry Engineering

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2024

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Vol. 24, iss. 1

158--164

EN

In view of the increasing scarcity of bauxite resources in China, the high energy consumption and high pollution of electrolytic aluminum, and the requirements for energy conservation and environmental protection, aluminum recycling and high-value utilization of its derivatives have evolved into a crucial development requirement for the aluminum industry in the future. As an important part of the development of recycled aluminum resources, the high-value application of scrap aluminum cans has always been a hot research topic in various recycled aluminum processing enterprises and scientific research units. The traditional regeneration system of waste cans includes a series of complex technological processes such as pretreatment, paint removal, smelting system and casting system, which is difficult to control in the middle of the process. Most of the recycled scrap aluminum cans are cast and downgraded for later use, except for a part of them used as alloy materials for new cans. In this paper, combined with the research on the preparation of metal aluminum alkoxide, combined with recrystallization heat conduction to further study the effective dissolution or adsorption how to remove impurity elements to obtain high-purity aluminum alcohol salt mechanism research, and thermal effect of alcohols with different carbon chains on the synthesis of high-purity aluminum alkoxide was further investigated. Moreover, the changes in morphology and pore size distribution of hydrolyzed alumina precursor materials under different hydrothermal temperature conditions were discussed by means of the alkoxide hydrolysis-sol-gel process. Eventually, the aluminum alkoxide was obtained by the reaction of waste cans with isopropanol and heavy crystal thermal conductivity, and the high-purity aluminum alkoxide was purified by vacuum distillation. Under the hydrothermal condition of 160°C, the high-purity alumina material with a purity of 99.99% and an original crystal size of 200nm was prepared.

14

Structure of ADI Cast Iron as a Cast “in situ” Composite Reinforced with TiC Ceramic Particles

Marosz J., Kawalec M., Górny M.

Archives of Foundry Engineering

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2024

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Vol. 24, iss. 4

95--102

EN

This paper presents a novel technology for the production of a casting material, which is an “in situ” composite on an ADI iron matrix reinforced with titanium carbide particles. As a result of the initiated Self-propagating High-temperature Synethesis reaction in Bath (liquid metal) of the type “solid Ti” – “solid C” type, led to the formation of ceramic phases in the form of titanium carbides. This method, allowed the synthesis of a cast composite based on ductile cast iron and, after subsequent heat treatment, the transformation of this material into ADI cast iron. The greatest advantage of “in situ” composites is that they are produced in a one-step metallurgical process, which is characterised, among other things, by: high thermodynamic stability, synthesis of a reinforcing phase in a metal bath, small size of ceramic particles with the possibility of controlling their dimensions by reaction kinetics parameters during the synthesis process. In this study, metallographic analysis of the composite obtained, both in the initial state and after heat treatment, was carried out using optical and scanning electron microscopy. An analysis of the chemical composition in the micro-area was carried out using the EDS method, the chemical composition was studied using the XRF spark X-ray fluorescence method, and the proportion of graphite and the carbide phase, i.e. titanium carbide TiC, was determined. The results obtained confirmed the possibility of obtaining the composite material via the SHSB reaction route. The heat treatment results showed that the carbides are thermodynamically stable and do not dissolve at temperatures designed for the production of ADI cast iron. The SHSB reaction guarantees a uniform distribution of titanium carbides on the ADI cast iron matrix.

15

Effect of Heat Treatment T6 on Selected Properties and Structure of AlSi5Cu2Mg Alloy with Addition of Mo, Zr, and S

Sýkorová M., Bolibruchová D., Brůna M., Hradečný K.

Archives of Foundry Engineering

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2024

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Vol. 24, iss. 4

5--14

EN

The hypoeutectic aluminum alloy AlSi5Cu2Mg is used for the production of high-strength automotive components such as cylinder head castings. AlSi5Cu2Mg alloy is characterized by a specific chemical composition (low permitted Si and Ti content) determined by the supplier. Due to the low permitted Ti content it is impossible to refine the grain structure of this aluminum alloy using standard grain refiners based on Al-Ti-B. Al-Si-Cu-Mg alloys are thermal stable up to the temperature 200°C, due to the presence of strengthening precipitates. Due to the downsizing, the operating temperature exceeds the temperature of 200°C, which leads to a decrease in the mechanical and physical properties of Al-Si-Cu-Mg alloys. The aim of this study is to analyse influence the alloying elements and heat treatment on the selected properties of AlSi5Cu2Mg alloys that are crucial for cylinder head castings. The paper focuces on the evaluation of the influence of selected alloying elements Sr, Zr and Mo on mechanical and physical properties. The present work also analysis the effect of heat treatment T6 on selected properties and structure of AlSi5Cu2Mg alloy modified by Sr, Zr or Mo. Sr, Zr and Mo were added into the AlSi5Cu2Mg alloy in the form of master alloys AlMo10, AlSr10 or AlZr20. According to the findings, the incorporation of the chosen alloying elements did not result in a substantial improvement in the mechanical and physical characteristics of AlSi5Cu2Mg alloy, which would be critical for its practical application. Physical and mechanical properties noted positive increase due to the effect of thermal processing T6.

16

Effect of Addition of Ti on Selected Properties of AlSi5Cu2Mg Alloy

Sýkorová Martina, Bolibruchová D., Brůna M., Chalupová M.

Archives of Foundry Engineering

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2024

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Vol. 24, iss. 3

10--17

EN

The paper focuses on the investigation of the influence of Ti on selected properties of the hypoeutectic aluminium alloy AlSi5Cu2Mg. AlSi5Cu2Mg alloy finds application in the field of production of high-strength cylinder head castings intended for the automotive industry due to the optimal combination of mechanical, physical and foundry properties. In commercial production, the maximum Ti content is limited by the manufacturer (Ti max. = 0.03 wt.%), which significantly limits the possibilities of refinement the alloy with Ti-based grain refiners. Therefore, the possibility of increasing the Ti content beyond the manufacturer's recommendation is considered in this work. The main aim of the work is to evaluate the influence of graded Ti addition (0.1; 0.2; 0.3 wt.% Ti) on the resulting mechanical and physical properties of the AlSi5Cu2Mg alloy. Simultaneously, the influence of increased Ti content on the microstructure of AlSi5Cu2Mg alloy is evaluated. The alloying element was introduced into the melt in the form of AlTi5B1 master alloy. The effect of T6 heat treatment on the resulting mechanical and physical properties and microstructure of the hypoeutectic AlSi5Cu2Mg alloy with graded Ti addition was also investigated in the experimental work.

17

Characteristics of High-Strength Cast Steel Micro-Alloyed with Vanadium

Białobrzeska Beata

Archives of Foundry Engineering

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2024

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Vol. 24, iss. 1

66--79

EN

This article presents the results of research into the characteristics of cast steel alloyed with chromium and vanadium, subjected to heat treatment for increased strength parameters. In the first part, it discusses the state-of-the-art knowledge regarding technological developments in the field of cast-steel alloys and the influence of individual alloying additives on the microstructure and the properties of the steel alloy. Further sections present the results of microstructure observations performed with light microscopy, scanning electron microscopy, and transmission electron microscopy. This research focuses on the material in the state directly after casting and after heat treatment, which involved quenching and tempering at 200 °C. The microstructural analysis performed as part of this research has informed the discussion of the results obtained from tensile and impact strength tests. The article also includes the results of a fractography analysis performed as the final part of the tests and offers a general summary and conclusions.

18

Application of SiC Based Moulding Sand in Technology of Layered Castings

Przyszlak Natalia, Wróbel T.

Archives of Foundry Engineering

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2024

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Vol. 24, iss. 3

115--122

EN

The article concerns the technology of layered castings made with a system where the base part is made of gray cast iron with flake graphite and the working part is made of high-chromium steel X46Cr13. The castings were produced using mould cavity preparation method utilizing a molding sand based on SiC. The idea of the research was to perform heat treatment of X46Cr13 steel directly in the casting mould, with the success of this approach guaranteed by selecting molding sand with appropriate physicochemical parameters. During the pouring and cooling of the mould, the temperature on the outer surface of the steel insert was recorded to check if it reached the required austenitization temperature. The castings were then examined for the quality of the bond between the gray cast iron base part and the steel working part, microstructure studies were conducted using light and scanning microscopes, and hardness was measured on the surface of X46Cr13 steel. Based on the conducted research, it was found that the high thermal conductivity of the molding sand made with a silicon carbide base disqualifies it for use in the analyzed technology of integrating heat treatment of X46Cr13 steel with the process of producing a bimetal system with gray cast iron. In the microstructure of the steel, in addition to martensite, pearlite and ferrite were present. Therefore, a satisfactory increase in the hardness of the working surface compared to the annealed state of X46Cr13 steel was not achieved, which ultimately confirmed that the hardening of the steel insert was unsuccessful.

19

Strong strain‑hardening capability in plain carbon steel through cold rolling and heat treatment of lamellar structure

Talebi Fatemeh, Jamaati Roohollah, Hosseinipour Seyed Jamal

Archives of Civil and Mechanical Engineering

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2024

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Vol. 24, no. 1

art. no. e44, 2024

EN

In the current research, strong strain-hardening capability in 1045 carbon steel was achieved by cold rolling and heat treatment of the lamellar structure. After 60% cold rolling, the proeutectoid ferrite and pearlite were severely elongated along the rolling direction. Cementite layers with brittle nature were fragmented under the action of stress and also by shear band formation during rolling. The lamellar heterogeneous microstructure of the heat-treated samples was formed by the proeutectoid ferrite as the soft domain and the pearlite as the hard domain. Increasing the heat treatment duration promoted the spheroidization transformation of cementite, and the spheroidization degree of cementite increased. With the increase in the time of heat treatment, the number of recrystallized grains is increased. Heat treatment led to weakening the deformation texture (⟨100⟩‖ND or θ fiber) and strengthening the recrystallization texture (⟨110⟩‖ND or ζ fiber). The heat-treated steels revealed an average microhardness value much higher than its macrohardness due to changes in the texture of ferrite grains. Heat treatment decreased the strength and hardness, and increased the ductility and toughness of steel compared to the cold-rolled sample owing to the annihilation of dislocations and the strengthening transition from strain hardening to grain refinement. The heat-treated samples exhibited a wider range of uniform plastic deformation and a larger strain hardening rate than the cold-rolled sample owing to the occurrence of the recovery of strain hardening rate phenomenon. The appropriate collocation of the fine spherical cementite and the soft/hard domains (with a large difference in mechanical properties) was beneficial to obtaining excellent strength-ductility balance in plain medium carbon steel. After heat treatment, the extent of ductile fracture considerably increased. With increasing the time of heat treatment from 1 to 3 h, the number of lamellar dimples decreased owing to the creation of more fine spherical cementite

20

Microstructure evolution and dynamic recrystallization mechanisms of 316L stainless steel during hot deformation

Zhao Guanghui, Tian Yinghao, Li Huaying, Ma Lifeng, Li Yugui, Li Juan

Archives of Civil and Mechanical Engineering

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2024

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Vol. 24, no. 1

art. no. e35, 2024

EN

Through isothermal compression testing at various temperatures and strain rates, the thermal deformation behavior of 316L stainless steel was investigated. Utilizing corrected true stress–strain data, an Arrhenius constitutive model with strain compensation was developed. Electron backscatter diffraction and transmission electron microscopy were employed to study the microstructure of the compressed specimens, revealing substantial impacts of temperature and strain rate. Higher temperatures boosted the transition from low-angle to high-angle grain boundaries (HAGB), while also increasing the volume percentage of dynamic recrystallization (DRX) and grain size. The impacts of Dynamic Grain Growth/Dynamic Abnormal Grain Growth restricted DRX at higher deformation temperatures and lower strain rates, but at lower temperatures, HAGB reduced with increasing strain rate. As a result, the proportion of HAGB and the volume fraction of recrystallization both decreased. The percentage of ∑3 n (1 ≤ n ≤ 3) twin boundaries also rose with temperature and followed a similar pattern to HAGB with strain rate. High temperature and high strain rate were the ideal formation conditions. Discontinuous dynamic recrystallization (DDRX) was the predominant DRX mechanism in the steel during thermal deformation, with continuous dynamic recrystallization (CDRX) acting as an auxiliary mechanism largely occurring in the low-temperature and high-strain-rate processing conditions like 1273–1323 K, 0.1–1 s −1 . Additionally, when the temperature rose, CDRX was suppressed while DDRX was encouraged.