Wyniki wyszukiwania - BazTech

1

FEM simulation of a novel medical device for TMJ therapy

Kwieciński K., Żmudzki Jarosław, Chladek G., Popielski P., Kowalczyk M., Duraj E., Sołtysiak-Niedziela M.

Archives of Materials Science and Engineering

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2023

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Vol. 122, nr 1

34--41

EN

Purpose: Temporomandibular disorders (TMD) are one of the leading health problems in dentistry. The work aimed to evaluate, using FEM, the influence of the material elastic properties of the flexible obstacle of the tongue trainer on the range of deflection and strength. Design/methodology/approach: In prototyping the trainer tongue, the starting point was real models with different extents of the tongue obstacle. moulded from dental wax on a dental stone model. Then versions were tested intraorally for the perception of the space occupied by the tongue. The models were scanned on a 3D scanner, and then a parametric CAD model (NX Siemens) was made on their basis. Finally, in order to take into account, the anatomical aspects, the two extreme ranges of the tongue obstacle, named "Long " and " Short ", were developed. Simulation deflection and material strength tests were made using FEM in the linear range (NX Siemens). Calculations were made for materials with Young's modulus equal to 8 MPa, 80 MPa and 800 MPa. The interaction of the tongue with the force of 5N was assumed. The support was provided by the retention surface on the teeth, with the support of the posterior edge of the obstacle on the palate (palatal variant) or lack of support, i.e., the obstacle freely bending in this area (free variant), was additionally tested. In order to assess the drop or retention of the trainer on the teeth, the second type of simulation was performed with the assumption of horizontal (anteriorly directed) tongue pressure with the force of 10N for the condition of rigid support in the area of the teeth and the periodontal zone from the lingual side. In this variant, a simulation was adopted for a material with a modulus of elasticity E=80 MPa. Findings: The stress values of the flexible obstacle of the trainer were obtained, allowing for the selection of potentially valuable materials for the trainer's construction. The results obtained in the simulations indicate the possibility of using ethylene vinyl acetate (EVA) and its blends. The accumulation of saliva inside the sealed obstacle was found, which indicated the need to look for an area to perforate without losing the load capacity of the obstacle. The structural feasibility of solving the problem of saliva accumulation without a significant change in the load capacity and stiffness of the obstacle was confirmed by simulation. Research limitations/implications: Simplifying the model to a linear range does not allow buckling analysis. In addition, the assumption of a linear material further limits the possibility of analysing materials with softening and plateau characteristics, where the compliance of the structure leads to elastic buckling. Practical implications: The range of deflections and stresses for different stiffness of the elastic element of the trainer was determined in order to select the appropriate material for the medical device (MD). Polyurethanes or silicones provide the range of deflection and strength, but in the case of manufacturing prefabricated trainers thermoformed in the patient's mouth (maximum temperature 75°C), the material that can be used is ethylene vinyl acetate (EVA). Originality/value: Simulation tests made it possible to determine the range of deflections and stress for different stiffness of the flexible obstacle of the trainer in order to select the appropriate material for the medical device.

2

Fabrication of a high wear resistance AA7075/AL2O3 composites via liquid metallurgy process

Sivaraman R., Jalil Abduladheem Turki, Aravindhan Surendar, Nan Zhao, Vini M. Heydari, Daneshmand S.

International Journal of Applied Mechanics and Engineering

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2022

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Vol. 27, no. 4

205--210

EN

In the present study, AA7075/Al2O3 composites have been fabricated via liquid metallurgy process. AA7075 alloy and Al2O3 particles were taken as the base matrix and reinforcements, respectively. Then, contents of 3 and 6 wt. % of Al2O3 subdivisions were added into the AA7075 matrix. To improve wettability and distribution, reinforcement particles were pre-heated to a temperature of 550°C for each composite sample. A hardened EN32 steel disc as the counter face was used to evaluate the wear rate pin-on-disc. The results showed that the wear rate of the AA/Al2O3 composites was smaller than that of the monolithic AA7075 samples. Finally, the worn surfaces of samples were investigated by SEM.

3

Influence of gradient structure on wear characteristics of centrifugally cast functionally graded magnesium matrix composites for automotive applications

Saleh Bassiouny, Jiang Jinghua, Fathi Reham, Xu Qiong, Li Yuhua, Ma Aibin

Archives of Civil and Mechanical Engineering

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2021

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Vol. 21, no. 1

196--218

EN

In the past few years, the functionally graded materials (FGMs) have proved useful in many industrial applications such as aerospace, automotive, transportation and infrastructure because of their advantages like the ability to control mechanical properties, residual stresses, wear, and corrosion behavior through a smooth gradation of the elements in a particular direction of the products. In this current work, the microstructural and wear properties of AZ91 alloy reinforced with silicon carbide particles (SiCp) produced through the centrifugal casting method were investigated. Four weight fractions of SiCp with 10 µm average size were used to fabricate functionally graded (FG) tubes in the two mold rotational speeds of 1200 and 1500 rpm. Microstructural, microhardness, and wear tests were used for characterizing the developed FG tubes. From the results obtained, the gradient distribution of SiC particles inside the AZ91 matrix alloy substantially improved hardness and wear resistance for the FG tubes comparing to unreinforced alloy. Moreover, the mold rotational speed is the main factor in controlling the distribution of particles, thus determining the gradient properties of the manufactured FG tubes. These findings suggest that FG tubes are useful for aerospace and automotive applications that require more excellent surface resistance.

4

Innowacyjna stal wysokokrzemowa z regulowaną niską zawartością zanieczyszczeń i wtrąceń niemetalicznych o kontrolowanej morfologii oraz odpowiednim poziomie inhibitora AlN z przeznaczeniem na wysokojakościowe blachy transformatorowe

Różański Piotr, Radwański Krzysztof, Niesler Marian, Woźniak Dariusz, Zdonek Bogdan, Mazur Artur, Pidvysots’kyy Valeriy, Kuziak Roman, Maracha Grzegorz, Fraś Wojciech

Journal of Metallic Materials

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2020

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Vol. 72, no. 2

63--82

PL

W artykule przedstawiono przebieg i wyniki badań przemysłowych wykonanych w ramach 1 Etapu projektu, którego końcowym celem jest opracowanie innowacyjnej stali elektrotechnicznej nowej generacji, przeznaczonej na blachy transformatorowe o wysokiej przenikalności magnetycznej (wysokiej indukcji 1,9 T i małej stratności 0,8 W/kg) z ziarnem zorientowanym (typ HGO) wraz z technologią jej wytwarzania w zakresie: wytapiania w konwertorze z obróbką pozapiecową uwzględniającą próżniowe odgazowanie stali w demonstracyjnej instalacji, ciągłego odlewania wlewków płaskich i walcowania ich na gorąco na półwyrób do dalszego przerobu. Pozostałe etapy wytwarzania blach transformatorowych obejmujące walcowanie na zimno, międzyoperacyjną obróbkę cieplną i cieplno-chemiczną oraz obróbkę powierzchniową stanowią tajemnicą przedsiębiorstwa. W ramach 1 Etapu projektu wykonano symulacje numeryczne i fizyczne wytapiania, odlewania i walcowania na gorąco stali o założonych parametrach jakościowych, celem uzyskania materiału do dalszych badań. Określono parametry wytapiania i odlewania zapewniające uzyskanie odpowiedniej jakości stali o maksymalnej zawartość tlenu całkowitego 12 ppm i udziale powierzchniowym wtrąceń niemetalicznych max. 0,05%, oraz wymagania techniczno-technologiczne urządzenia do obróbki ciekłej stali w próżni, stanowiącego instalację demonstracyjną, a także opracowano model reologiczny stali transformatorowej dla procesu walcowania blach na gorąco, z użyciem którego przeprowadzono wstępne symulacje w celu uzyskania rozkładów temperatury, odkształcenia i prędkości odkształcenia w walcowanym paśmie.

EN

The article presents the process and results of industrial tests carried out as part of the 1st Stage of the project, the final goal of which is to develop an innovative new-generation electrical steel designed for the manufacture of transformer plates with high magnetic permeability (high inductance of 1.9 T and low lossiness of 0.8 W/ kg) and with oriented grain (HGO type) together with the technology of its production in the scope of: melting of steel in a converter with ladle treatment taking into account vacuum degassing of steel in a demonstration installation, continuous casting of flat ingots and their hot rolling for further processing. The remaining stages of transformer plate production, including cold rolling, inter-operational heat and thermo-chemical treatment, as well as surface treatment operations, are a trade secret. As part of the 1st Stage of the project, numerical and physical simulations of melting, casting and hot rolling of steel with assumed quality parameters were carried out in order to obtain material for further research. The melting and casting processes parameters were determined to ensure obtaining the appropriate quality of steel with a maximum total oxygen content of 12 ppm and the surface fraction of non-metallic inclusions of max. 0.05%, technical and technological requirements for the device for liquid steel processing in vacuum constituting the demonstration installation were determined, and a rheological model of transformer steel for the sheet hot-rolling process was developed, with the use of which preliminary simulations were carried out to obtain temperature, deformation and strain rates in the rolled strip.

5

Influence of alloying elements on the microstructure of new cobalt matrix superalloys reinforced with phase - L12

Jung Tymoteusz, Kierat Milena

Journal of Metallic Materials

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2020

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Vol. 72, no. 4

27--30

EN

The article presents selected results of research on the primary structure of a new generation of cobalt-based Co-20Ni-10Al-5Mo-2Nb superalloys. Research on this group of materials was started in 2006 by J. Sato. These materials are anticipated to be able to replace nickel-based superalloys in the future due to their superior elevated temperature properties compared to the nickel-based superalloys. Today, γ’ nickel-based superalloys are still unrivalled in aerospace applications, however, cobalt-based superalloys are a response to their existing limitations, which do not allow the current pace of aircraft engine development to be maintained.

PL

W pracy przedstawiono wybrane wyniki badań nad pierwotną strukturą nowej generacji nadstopów na osnowie kobaltu typu Co-20Ni-10Al-5Mo-2Nb. Badania nad tą grupą materiałów rozpoczął w 2006 roku J. Sato. Przewiduje się, że materiały te w przyszłości mogą zastąpić nadstopy na osnowie niklu ze względu na ich doskonałe właściwości w podwyższonej temperaturze w porównaniu z nadstopami na osnowie niklu. Obecnie nadstopy na osnowie niklu wzmacniane fazą γ’ są nadal bezkonkurencyjne w zastosowaniach lotniczych, jednak nadstopy na bazie kobaltu są odpowiedzią na ich istniejące ograniczenia, które nie pozwalają na utrzymanie obecnego tempa rozwoju silników lotniczych.

6

An Evaluation of the Effect of Ultrasonic Degassing on Components Produced by High Pressure Die Casting

Silva da Manel, Bajusz Attila, Pabel Thomas, Petkov Tose, Plantà Xavier

Journal of Casting & Materials Engineering

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2020

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Vol. 4, no. 4

58--64

EN

Ultrasonic treatment is known to be efficient for aluminium melt degassing with the additional benefits of being both economical and environment friendly. This paper describes the effect of ultrasonic degassing on the preparation of an AlSi9Cu3(Fe) alloy for High Pressure Die Casting (HPDC). The degassing efficiency was assessed in terms of the indirect evaluation of the melt, by means of the reduced pressure test and the porosity evaluation of the cast parts. Additionally, the corresponding hydrogen content was estimated with an experimental equation reported in the literature. Ultrasonic degassing shows greater efficiency in terms of hydrogen removal from the melt than conventional N2 + Ar lance bubbling. Components produced by HPDC without degassing, with ultrasonic degassing and with lance degassing, were analysed by computed tomography and by metallography. The results show that the components produced by HPDC after ultrasonic degassing have a similar porosity level to components degassed with conventional lance bubbling, both showing an important improvement over components produced without degassing treatment. Hardness values were similar for all different treatment conditions and well over the minimum value established for the alloy by the corresponding standard.

7

Study of the microstructure and mechanical characteristics of AZ91–SiCp composites fabricated by stir casting

Saleh Bassiouny, Jiang Jinghua, Fathi Reham, Xu Qiong, Wang Lisha, Ma Aibin

Archives of Civil and Mechanical Engineering

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2020

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Vol. 20, no. 3

102--115

EN

In recent years, the composite materials have been very desirable by researchers for many engineering applications such as aviation and biomedical because of the tremendous characteristics of magnesium matrix metal composite. This current investigation aims to develop the AZ91/SiCp composites with various weight fractions (0, 2.5, 5 and 10 wt%) of silicon carbide particles via the stir casting method. The effect of SiC particles content on microstructure, mechanical and wear behaviour was investigated. The optical microscope, scanning electron microscopy and EDX analyses were utilized to detect the distribution of hard particles as well as the interface between the alloy and particles. Based on the findings, the homogeneous distribution of particles, refinement of grains in addition to good bonding between AZ91 alloy and particles have been achieved in produced composites. Therefore, the mechanical characteristics and wear performance are improved in composites compared with the unreinforced alloy. Moreover, these results suggest that for applications demanding high mechanical properties and wear resistance the AZ91/SiCp will be effective composites.

8

The impact of the melting and pouring process on the quality of the biggest rocking bell called Vox Patris

Bartocha Dariusz, Baron Czesław

Quality Production Improvement - QPI

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2019

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Vol. 1, Iss. 1

230--237

EN

The paper describes the process of melting, metalworking and pouring the form of the world's largest 55-ton rocking bell called Vox Patris. The project was carried out by Pracownia Ludwisarska of Jan Felczyński from Przemyśl in cooperation with Rduch Bells & Clocks from Czernica and Metalodlew SA from Kraków. Comprehensive scientific and technical support of the project was provided by the Department of Foundry of the Silesian University of Technology. The bell is made of bronze, which is an alloy of copper and tin with a content of tin at the level of 20%. The foundry, where the melting and pouring process took place, had two 14 ton electric furnaces, 15 ton transport pouring ladle and a 60 ton collection ladle. Therefore, it was necessary to determine the minimum temperature of the pouring and the conditions for holding the liquid metal so that the metal from the first cast would not solidify before accumulating its total amount (four melts) (Bartocha and Baron, 2015; Bartocha and Baron, 2016). The study presents the tests of alloy properties and a series of computer simulations. Thanks to them the maximum and minimum permissible temperature of metal overheating has been determined (Bartocha, 2017). The final stage of the cast was the mold pouring process. The filling system was responsible for the correct performance of this process. This system comprised a tank (collector) under a doublestopper 60-ton main ladle, an elevenmeter tapping spout, an infusion tank and a downgate. The task of the gating system is uniform and continuous supply of liquid metal to the mold until it is completely filled. The unusual layout, that was used, required checking many factors. Various configurations of the system parameters have been tested based on the series of computer simulations (Czochlarski and Bukowski, 1935; Ignaszak, 1999).

9

The Influence of the Proportion of Charge from Waste Materials on the Quality of High Pressure Castings

Schlafka P., Bydałek A. W.

Archives of Foundry Engineering

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2019

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iss. 2

21--24

EN

Nowadays, the most popular production method for manufacturing high quality casts of aluminium alloys is the hot and cold chamber die casting. Die casts made of hypereutectoid silumin Silafont 36 AlSi9Mg are used for construction elements in the automotive industry. The influence of the metal input and circulating scrap proportion on porosity and mechanical properties of the cast has been examined and the results have been shown in this article. A little porosity in samples has not influenced the details strength and the addition of the circulating scrap has contributed to the growth of the maximum tensile force. Introducing 80% of the circulating scrap has caused great porosity which led to reduce the strength of the detail. The proportion of 40% of the metal input and 60% of the circulating scrap is a configuration safe for the details quality in terms of porosity and mechanical strength.

10

Microwave-Hardened Moulding Sands with Hydrated Sodium Silicate for Modified Ablation Casting

Puzio S., Kamińska J., Major-Gabryś K., Angrecki M., Hosadyna-Kondracka M.

Archives of Foundry Engineering

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2019

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iss. 2

91--96

EN

The aim of this study is to demonstrate the possibility of using moulds made from the environmentally friendly sands with hydrated sodium silicate in modified ablation casting. The ablation casting technology is primarily intended for castings with diversified wall thickness and complex shapes made in sand moulds. The article presents the effect of binder content and hardening time on the bending strength Rgu of moulding sands with binders based on hydrated sodium silicate hardened by microwave technology. The aim of the research was to develop an optimal sand composition that would provide the strength necessary to make a mould capable of withstanding the modified ablation casting process. At the same time, the sand composition should guarantee the susceptibility of the mould to the destructive action of the ablation medium, which in this case is water. Tests have shown that microwave hardening provides satisfactory moulds’ strength properties even at a low binder content in the sand mixture.

11

Introducing Advanced Data Analytics in Perspective of Industry 4.0 in a Die Casting Foundry

Perzyk M., Dybowski B., Kozłowski J.

Archives of Foundry Engineering

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2019

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iss. 1

53--57

EN

The paper presents some aspects of a development project related to Industry 4.0 that was executed at Nemak, a leading manufacturer of the aluminium castings for the automotive industry, in its high pressure die casting foundry in Poland. The developed data analytics system aims at predicting the casting quality basing on the production data. The objective is to use these data for optimizing process parameters to raise the products’ quality as well as to improve the productivity. Characterization of the production data including the recorded process parameters and the role of mechanical properties of the castings as the process outputs is presented. The system incorporates advanced data analytics and computation tools based on the analysis of variance (ANOVA) and applying an MS Excel platform. It enables the foundry engineers and operators finding the most efficient process variables to ensure high mechanical properties of the aluminium engine block castings. The main features of the system are explained and illustrated by appropriate graphs. Chances and threats connected with applications of the data-driven modelling in die casting are discussed.

12

Comparison of Molding Sand Technology Between Alphaset (APNB) and Furan (FNB)

Ghosh Dipak K.

Archives of Foundry Engineering

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2019

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iss. 4

11--20

EN

The paper focuses on investigation of properties of two most widely used self-set sand binder systems APNB and FNB across the Globe, for making molds and cores in foundries to produce castings of different sizes involving wide range of metals and alloys, ferrous and nonferrous. This includes study of compression strength values of samples made out of molding sand at different binder addition level using new, mechanically reclaimed (MR) and thermally reclaimed (TR) sand. Strength values studied include dry strength (at room temperature) at specified intervals simulating different stages of mold handling, namely stripping and pre heating, followed by degraded strength after application of thinner based zircon wash by brush, subsequent lighting of, then checking strength both in warm (degraded strength) & cold (recovered strength) conditions. Throughout the cycle of mold movement from stripping to knock out, strength requirements can be divided into two broad classifications, one from stripping to closing (dry strength) and another from pouring to knock out (hot & retained strength). Although the process for checking of dry strength are well documented, no method using simple equipments for checking hot & retained strength are documented in literature. Attempts have been made in this paper to use some simple methods to standardize process for checking high strength properties using ordinary laboratory equipments. Temperature of 450°C has been chosen by trial & error method to study high temperature properties to get consistent & amplified values. Volume of gases generated for both binders in laboratory at 850°C have also been measured. Nature of gases including harmful BTEX and PAH generated on pyrolysis of FNB and APNB bonded sands are already documented in a publication [1]. This exercise has once again been repeated in same laboratory, AGH University, Poland with latest binder formulations in use in two foundries in India.

13

The influence of additive technology on the quality of the surface layer and the strength structure of prosthetic crowns

Bojko Ł., Ryniewicz W., Ryniewicz A. M., Kot M., Pałka P.

Tribologia

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2018

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nr 4

13--22

EN

Prosthetic crowns reproduce the damaged hard structures of the patient’s own teeth and take over their natural functions, thus securing the correct reconstruction of the stomatognathic system. The aim is to evaluate the crowns for premolars and molars produced by casting, milling, and Selective Laser Melting technologies, in terms of the accuracy of reproducing the degree against the prosthetic pillar, the analysis of the surface layer structure of the step, and the micromechanical parameters of the alloy. The study material included CoCrMo alloy crowns. The conducted study allowed finding that the tightness of prosthetic crowns made using traditional casting technology as well as in SLM milling and technology is comparable and meets clinical requirements. Structural crown analyses confirmed the very good quality of the surface layer obtained with milling technology and SLM technology using the CAD/CAM method. SLM and digital milling allow the formation of precise and durable structures constituting the foundation of crowns in a time much shorter than the casting process.

PL

Korony protetyczne odtwarzają uszkodzone twarde struktury zębów własnych pacjenta, przejmują ich naturalne funkcje i w ten sposób zabezpieczają prawidłową odbudowę układu stomatognatycznego. Celem jest ocena koron na zęby przedtrzonowe i trzonowe wytwarzane technologią odlewania, frezowania oraz Selective Laser Melting, w zakresie: dokładności odwzorowania stopnia względem filara protetycznego, analizy struktury warstwy wierzchniej stopnia, parametrów mikromechanicznych stopu. Materiałem badań były korony ze stopu CoCrMo. Przeprowadzone badania pozwoliły stwierdzić, że szczelność koron protetycznych wykonanych w technologii tradycyjnego odlewania oraz w technologii frezowania i technologii SLM jest porównywalna i spełnia wymogi kliniczne. Analizy strukturalne koron potwierdziły bardzo dobrą jakość warstwy wierzchniej uzyskiwanej w technologii frezowania oraz w technologii SLM metodą CAD/CAM. SLM i frezowanie metodą cyfrową pozwalają na wytworzenie precyzyjnych i wytrzymałych konstrukcji stanowiących podbudowy koron w czasie znacznie krótszym niż proces odlewniczy.

14

Badania nad procesem odlewania taśm ze stopów aluminium serii 6xxx metodą TRC oraz ich walcowanie na zimno

Ściężor W., Kowal R., Kiesiewicz G., Kwaśniewski P., Mamala A., Franczak K.

Rudy i Metale Nieżelazne Recykling

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2018

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R. 63, nr 3

3--9

PL

Aktualnie obserwowany globalny wzrost konkurencyjności blach i taśm aluminiowych zarówno w przemyśle motoryzacyjnym, lotniczym, jak i budowlanym, przyczynia się do wzrostu zapotrzebowania na wyroby zimnowalcowane ze stopów aluminium. Proces rozwoju współczesnych przedsiębiorstw zajmujących się wytwarzaniem wyrobów płaskich zimnowalcowanych skupia się wokół zwiększania wydajności procesu produkcyjnego. W związku z powyższym, coraz większe uznanie zyskują innowacyjne technologie bazujące na zintegrowanych procesach ciągłego odlewania i walcowania, pozwalających na uzyskiwanie wysokiej jakości wyrobów płaskich walcowanych na zimno z pominięciem operacji walcowania na gorąco. W artykule zostały opisane obszerne badania procesu wytwarzania taśm metodą Twin Roll Casting, a także szczegółowe badania ich własności mechanicznych, twardości, przewodności elektrycznej oraz ewolucji tych własności po odkształceniu w wyniku walcowania na zimno.

EN

Global increase in the use of aluminum sheets and strips can be easily observed nowadays in automotive, aviation and construction industry which causes the increase of demand for production of cold-rolled aluminum alloys. The development of modern industry concerned with manufacturing of cold-rolled flat products is mainly focused on increasing of production efficiency. Taking that into consideration, these days more and more approval is given to the technologies based on integrated processes of continues casting and rolling which allow to achieve high quality cold-rolled products with the omission of the hot-rolled process. One of the cold-rolled production processes used more commonly every day is the Twin Roll Casting method (TRC). This method allows the omission of a very expensive stage which is hot-rolling process. The charge from the TRC production line may directly undergo the cold-rolling process. This article widely discusses not only laboratory tests during the production of strips from alloy EN AW-6060 using the TRC method but also its mechanical properties, hardness, electric conductivity taking into account variables of a process and evolution of these properties after the cold-rolled deformation.

15

Microstructure formation and grain refinement of Al-Mg-Si-Mn casting alloys

Boyko V., Czekaj E., Warmuzek M., Mykhalenkov K.

Prace Instytutu Odlewnictwa

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2018

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Vol. 58, no. 4

251--260

EN

Together with development of casting technology for Al-Si-Mg alloys, new groups of casting materials are undergoes its implementation into foundry practice. Al-Mg-Si casting alloys possessed several advantages such as good strength in as-cast state combined with high ductility, good corrosion resistance and castability. In both Al-Si-Mg and Al-Mg-Si systems, the range of the eutectic crystallization occurs: L → αAl + βSi and L → αAl + Mg2Si, respectively. In the hypoeutectic alloys of both system as a primary phase – dendrites of the solid solution αAl solidify. The transition elements – Ti, Zr, Sc, which provides efficient grain refinement can dissolve in this solid solution αAl causing precipitation strengthening effect. In the article the present state of the researches on the development of Al-Mg-Si casting alloys is considered together with the results of the examinations on the effect of Ti addition on the microstructure of the AlMg5Si2Mn alloy. These researches results were discussed at the annual conference on the casting of non-ferrous metals “Science and Technology” (2018) and initially presented in an shortened form in the article [1].

PL

Wraz z rozwojem technologii odlewniczych stopów Al-Si-Mg, także kolejne grupy materiałów znajdują zastosowanie w odlewnictwie. Stopy odlewnicze Al-Mg-Si charakteryzują się korzystnymi właściwościami nie tylko technologicznymi, jak np. dobra lejność, ale także odpowiednio wysoką wytrzymałością i plastycznością w stanie lanym czy też odpornością na korozję. W układach równowagi Al-Si-Mg i Al-Mg-Si występują odpowiednio obszary krystalizacji eutektycznej L → αAl + βSi oraz L → αAl + Mg2Si. W stopach podeutektycznych metale przejściowe, takie jak: Ti, Zr, Sc, dodawane przede wszystkim w celu rozdrobnienia pierwotnej struktury ziarn dendrytycznych, mogą rozpuszczać się w pierwotnej fazie αAl i powodować jej umocnienie wydzieleniowe. W pracy został omówiony aktualny stan badań nad odlewniczymi stopami Al-Mg-Si. Przedstawiono wyniki badań własnych dotyczących wpływu dodatku Ti na mikrostrukturę stopu AlMg5Si2Mn, które były dyskutowane w ramach konferencji „Science and Technology” (2018) oraz wstępnie omówione w publikacji [1].

16

Konwersja materiałowo-technologiczna stopów niklu. Część 2. Problemy technologiczne procesu odlewania

Pirowski Z.

Prace Instytutu Odlewnictwa

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2018

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Vol. 58, no. 4

321--330

PL

Celem drugiej części podjętych prac było wykonanie odlewów użytkowych z żarowytrzymałych stopów niklu, tradycyjnie przerabianych plastycznie, przeznaczonych do eksploatacji w ekstremalnie trudnych warunkach. Omówiono związane z tym problemy technologiczne i uzyskane efekty, tak w zakresie właściwości odlanych stopów, jak i jakości otrzymanych odlewów. Przedmiotem badań były stopy Inconel 740 (IN740) i Haynes 282 (H282), które stosowane są dotychczas wyłącznie jako stopy przerabiane plastycznie. Podjęto próby topienia ich w otwartym piecu indukcyjnym i odlewania grawitacyjnego. Wykazano, że właściwości mechaniczne tak otrzymanych stopów są w wysokiej temperaturze porównywalne, a nawet przewyższają właściwości ich odpowiedników przerabianych plastycznie. Potwierdzono, że przy zachowaniu odpowiednio dobrze opracowanego reżimu technologicznego możliwe jest wykonywanie z tych stopów odlewów dobrej jakości, przeznaczonych do pracy w temperaturze znacznie przekraczającej 760°C.

EN

The aim of the second part of the study was to make utility castings of refractory nickel alloys, traditionally processed plastically, intended for use in extremely difficult conditions. The related technological problems and obtained effects were discussed, both in terms of the properties of cast alloys and the quality of the castings obtained. Inconel 740 (IN740) and Haynes 282 (H282) alloys were the subject of research, which so far have been used only as plastically processed alloys. Attempts were made to melt them in an open induction furnace and gravity casting. It has been shown that mechanical properties of such alloys are comparable at high temperature and even exceed those of their counterparts processed plastically. It has been confirmed that with a well-developed technological regime it is possible to produce from these alloys of good quality castings intended for operation at temperatures significantly exceeding 760°C.

17

Propozycja oceny skurczu odlewniczego hybrydowych kompozytów epoksydowych stosowanych w transporcie morskim i lądowym

Bryll K., Deja A., Kaszycki L.

Autobusy : technika, eksploatacja, systemy transportowe

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2018

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R. 19, nr 12

62--65

PL

W niniejszej pracy określano wpływ połączenia dwóch materiałów fazy umocnienia, o skrajnych właściwościach mechanicznych, na skurcz objętościowy kompozytów hybrydowych o osnowie epoksydowej. Do badań zastosowano jako materiał umocnienia tworzywo pochodzące z recyklingu materiałowego ze względu na rozwijający się przemysł stoczniowy, który dąży do poszukiwań nowoczesnych sposobów zagospodarowania odpadów, powstających przy demontażu małych jednostek pływających. Materiał badawczy wytworzono w wyniku odlewania grawitacyjnego do formy półotwartej. Powstały kompozyt to: osnowa - żywica epoksydowa oraz umocnienie - włókna szklanego w udziale masowym 1%, jak również pianka poliuretanowa w udziale 1% do 10% masowym.

EN

This work determines the effect of combining two reinforcement phase materials, with extreme mechanical properties, on volume shrinkage of hybrid epoxy based composites. The strenghtening material used for the research was material recycled due to the developing shipbuilding industry, which seeks to search for modern ways of waste management, arising during the dismantling of small vessels. The research material was created as a result of gravity casting into a semi-open form of epoxy resin matrix and reinforcement of fiber glass (in mass fraction of 1%), as well as polyurethane foam (in the proportion of 1% to 10% by mass).

18

Recent advance in appliances and materials enhancing therapy of disorders of the stomatognathic system

Sołtysiak-Niedziela M., Kwieciński K., Żmudzki J.

Archives of Materials Science and Engineering

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2018

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Vol. 90, nr 2

74--84

EN

Purpose: Dysfunctions of the stomatognathic system are treated with a lot of appliances. The aim of the work was to evaluate the current state in the field of diagnostic techniques and technological advance in appliances and materials enhancing therapy of occlusion disorders of the stomatognathic system. Design/methodology/approach: The principles of appliances functioning, manufacturing technology and materials were analysed. The analysis was made on the basis of the literature review and patent databases, conducting searches for a combination of keywords: dental material, occlusion, disorder, bruxism, clenching, grinding, appliance, therapy, tongue, oral, exerciser, trainer, mandible muscle, bite splint, dental plate. In the case of principles of functioning, devices that require insertion into the mouth are included in the tests. In technology and materials, attention has been paid to necessity of involving a dental technician or ability to perform appliance intra-orally ("chairside"), as well as mass production with possibility of custom fit. Findings: The most widespread in the treatment of disorders of the stomatognathic system are thermoformed materials and devices that are introduced between the dental arches to counteract occlusions of all teeth or selected teeth or force the position of the mandible in relation to the maxilla. Devices that function differently are those in which therapeutic effects result from toning of activity of the elevating mandibular muscles by provoking activity of the opposing muscles lowering the mandible or reducing intra-oral space, for example, by sublingual plates or tongue trainers. Appliances are mainly manufactured of: poly (ethylene- vinyl acetate) or polycarbonates, as also mouldable polymers such as: acrylics, polyesters and rubbers. Research limitations/implications: Electronic devices that are not intended to therapy but used only to track mandible mobility or muscle activity during sleep were not taken into account. Practical implications: Solutions activating the action of the opposing muscles to the muscles lifting the mandible are few, and among them one device is retained on teeth without interfering in occlusion. Originality/value: Dental materials for dev/ices for treatment of occlusion disorders are selected with no understanding tines influence of elastic and frictional material properties and structures stiffness on the distribution of occlusion forces between the teeth and reactions in temporo-mandibular joints.

19

The Design of a Cast Suspension Element, Determined by the Pressure Wave

Żuczek R., Maj M., Piekło J., Pysz S.

Archives of Foundry Engineering

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2018

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Vol. 18, iss. 3

59--64

EN

Based on the example of the development process of the cast suspension of a special-purpose vehicle the application of the integrated engineering design methodology (ICME – Integrated Computational Materials Engineering) and the development of construction has been presented. Identification of the operating and critical loads, which are guidelines for carrying out the structure strength shaping process, material and technological conversion, are due to the needs and requirements of the suspension system and the purpose and objectives of the special mobile platform. The developed cast suspension element construction includes the use of high-strength AlZnMgCu aluminum alloy. The properties of the used alloy and designed shape allows for the transfer of assumed operating loads in normal exploitation conditions and in the dynamic, critical loads to the susceptibility to damage in the assumed casting areas. For the proposed design, conducted numerical analyzes includes the impact of the shock wave pulse on the occurrence of the destructive stress fields. Based on their distribution, the areas of possible decomposition of the structure of the design element were estimated. The results allowed to devise an element with predicted destructions that allow to absorb a significant part of the impact energy of the shock wave front, which is also the buffer zone for the propagation of destruction for the critical kinematic nodes of the system.

20

Effect of Cooling Rate and Pouring Temperature on the Hardness and Wear Resistance of Bronze SAE660

Karimifer S., Vahdat S. E.

Archives of Foundry Engineering

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2018

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Vol. 18, iss. 3

144--151

EN

Metallic bearing alloys have different types, most of which are tin (Babbitt) or bronze based. Bronze bearings are used at heavy duty conditions. The goal of this research is an investigation on the effect of cooling rate and pouring temperature (two important factors in casting production) on the Brinell hardness and pin-on-disc wear resistance (two important properties in bearing applications) of bronze SAE660. The melt had prepared by induction furnace. Then, it had poured in sand mold in four different casting conditions, including pouring temperatures of 950 ºC and 1200 ºC, and cooling with water and air. Finally, the microstructure, hardness and wear resistance of the SAE660 had investigated. The results indicated that if the maximum hardness, along with the minimum weight loss due to wear (or maximum wear resistance) is required; the contents of intermetallic compounds, lead phase and the solid solution phase should be more. In this way, the samples which are cooled in air and poured at 950 ºC have the high hardness and the lowest weight loss.