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1

Effect of Iron Phases Crystallization on the Durability of the Bimetallic Connection Between Ring Inserts and the Piston Casting

Szucki Michał, Piątkowski Jarosław, Czerepak M.

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 2

112--118

EN

The article presents the most important causes of the unstable connection between cast iron ring inserts and the silumin casting of an engine piston. It is shown that manufacturing defects are mainly related to the alfin processing of inserts in Al-Si alloy (the so-called AS9 alloy). Exceeding the permissible iron content in AS9 alloy causes the crystallization of brittle -Al5FeSi phases. Their unfavorable morphology and large size are the main reasons for the weakening of the diffusion connection between the inserts and the piston, causing an unacceptable proportion of defective products. The study presented in this work was conducted under industrial conditions on a population of 10.000 pistons. Quality control data, production parameters, as well as the micro- and macro-structures of the cast iron inserts, and the interface area between the inserts and the silumin piston, were analyzed. Material and technological solutions have been proposed to reduce the occurrence of casting defects at the insert-piston joint. This includes the introduction of so-called "morphological correctors" of the -Al5FeSi phases, reducing the possibility of gaseous impurities in the AS9 alloy and optimizing the temperature of the alfin alloy.

2

Role of Si on machined surfaces of Al-based automotive alloys under varying machining parameters

Razin Ahmed Asif, Ahammed Dewan Salsabil, Nur Maglub Al, Kaiser Mohammad Salim

Journal of Mechanical and Energy Engineering

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2022

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Vol. 6, No 1

43--52

EN

A morphological change due to Si contend into Al-based automotive alloys has been conducted on the characterization of machined surfaces in terms of roughness, temperature, chips formation as well as microstructure evaluation under different machining conditions. For this experiment, a shaper machine with HSS single point V-shaped cutting tool is used at different cutting speeds and depths of cut. The experimental results show that the surface roughness of the alloys decreases with the cutting speed and depth of cut but it is more prominent in the case of the cutting speed. This is because of a high cutting speed, which is more associated with the higher temperature and softening the work material leading to better surface finish. Higher Si added alloys also exhibit a better surface finish because the sample content is different fine and hard intermetallic due to ageing treatment, which also makes the alloys more brittle. For brittle and higher hardness, it produces a higher temperature during machining. During machining, relatively curly and short chips are formed by the high Si added alloy because of its low elongation properties. The fracture surfaces of higher Si added alloy display more crack propagation obtained by plate-like Si rich intermetallic.

3

Mechanical properties the Al-7%SiMg alloy with CuAl10Fe3Mn2 used in machine building and civil engineering

Lipiński Tomasz

Quality Production Improvement - QPI

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2020

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Vol. 2, Iss. 1

247--258

EN

Silumins are one of the most popular group among aluminum casting alloys. They are characterized by good mechanical and casting properties, low density, good electric and thermal conductivity, a low degree of contraction, good corrosion resistance and a relatively low melting temperature. The mechanical properties of hypoeutectic silumins can be improved through chemical modification as well as traditional or technological processing. Modification improves the mechanical properties of alloys through grain refinement. The effect of treatment has been given a lot of information first of all about microstructure and mechanical properties. This study presents the results of treatment of an Al-7%SiMg alloy with composition CuAl10Fe3Mn2 (as a powder) + (Al-7%SiMg + CuAl10Fe3Mn2) (as a powder) + (Al-7%SiMg + CuAl10Fe3Mn2) (in the form of a rod) in three different ranges. The experiments were conducted following a factor design 23 for 3 independent variables. The main addition was aluminum bronze, as well as clear or melted with raw alloy. The influence of the analyzed modifiers on the microstructure and mechanical properties of the processed alloy was presented in graphs. The modification of a hypoeutectic Al-7%SiMg alloy improved the alloy's properties. The results of the tests indicate that the mechanical properties of the modified alloy are determined by the components introduced to the alloy.

4

Tool wear characteristics in machining of hypereutectic Al-Si alloys by cemented carbide tool

Kobaru Yuya, Nagaoka Ryo, Shimana Kenji, Yoshimitsu Shinichi, Kondo Eiji

Journal of Machine Engineering

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2020

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Vol. 20, No. 2

94--103

EN

During of hypereutectic Al-Si alloys, tool wear increases owing to the presence of silicon particles. Therefore, polycrystalline diamond tools are typically used, but they are very expensive. The purpose of this study is to examine the tool wear characteristics during the end milling of hypereutectic Al-Si alloy (A390–T6) by using comparatively inexpensive diamond-like carbon coated cemented carbide tools. Al-Si alloy was end-milled by changing the cutting speed. Our results revealed that the width of flank wear land increased monotonously with increasing of the cutting force regardless of the cutting speed. In addition, the experimental equation of the width of flank wear land was derived as a function of cutting speed and time, and it was clarified that width of flank wear land could be approximated.

5

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.

6

Effect of Solution Treatment on Age-Hardening Behavior of Al-12Si-1Mg-1Cu Piston Alloy with Trace-Zr Addition

Kaiser M. S.

Journal of Casting & Materials Engineering

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2018

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Vol. 2, no. 2

30--37

EN

The influence of a solution treatment with a trace zirconium addition on the precipitation behavior of a cast Al-12%Si-1%Mg1%Cu piston alloy has been reported. The alloys were prepared by controlled melting and casting. The cast alloys were given an age-hardening treatment having a sequence of homogenization, T6 solutionizing, quenching, and aging. Both the cast and solutionized samples were naturally aged for 58 days, isochronally aged for 60 minutes at different temperatures (up to 350°C), and isothermally aged at various temperatures (up to 225°C) for different periods of time (ranging from 15 to 360 minutes). The hardness values of the differently processed alloys were measured to understand the aging behavior of the alloys. Electrical resistivity changes with aging time and temperature were measured to understand the precipitation behavior of the alloys. It is observed that significant hardening takes place in the aged alloys due to the formation of GP zones as well as the formation of metastable phases. The solutionizing treatment improves the hardness because some alloying elements are re-dissolved during solution treatment to produce a solute-rich solid solution. The trace-added Zr hinders the softening due to the precipitation of Al3Zr, which is very stable against coarsening and the re-dissolution of precipitates. Electrical resistivity decreases due to stress relieving, the dissolution of the metastable phase, and precipitation coarsening. The resistivity of the solutionized alloys decreases more due to the higher concentration of elements in the solid solution. A microstructural study of the alloys reveals that the solution treatment improves the distribution of the silicon grains. It is also observed that the alloys attained an almost fully re-crystallized state after aging at 350°C for 90 minutes.

7

Production of Melt-Spun Al-20Si-5Fe Alloy and Boron Carbide (B4C) Composite Material

Kilicaslan M. F., Uzun A., Karakose E.

Archives of Metallurgy and Materials

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2018

|

Vol. 63, iss. 2

597--600

EN

In this study, metal matrix composite materials containing melt-spun Al-20Si-5Fe alloys and boron carbide was produced by high energy ball milling and then hot pressing at 200 MPa pressure and 450°C. Mechanical and microstructural characterizations were performed by using an optical microscopy, X-Ray diffractometer, and dynamic microhardness tester. It was observed that boron carbide particles were homogenously distributed in the microstructure and values of microhardness and elastic modules were averagely 830 MPa and 42 GPa, respectively.

8

Influence of Modifications on Fatigue Strength of AlSi17Cu5Mg(Fe) Alloy Used for Pistons for Internal Combustion Engines

Piątkowski J., Wieszała R.

Archives of Metallurgy and Materials

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2018

|

Vol. 63, iss. 1

135--141

EN

Technological progress in construction of automotive vehicles, particularly in construction of engines, enforces simultaneous changes in foundry properties of aluminum alloys used in automotive industry. Until recently, abrasion resistance was the main usability criterion of a material used for pistons for internal combustion engines. At present however, because of the complexity of the process of the fuel mixture combustion, more restrictive standards of limited hydrocarbon emission, and the pursuit of reduction of the vehicle’s mass, fatigue strength of silumins enjoys a continuously increasing interest. The paper presents results of a computer simulation using the finite element method (FEM) and a real fatigue test of AlSi17Cu5Mg(0.5Fe) (A390.0) alloy with unilateral variable bending. The tests aimed to simulate a deflection of a combustion engine piston in a cylinder barrel were carried out in two variants: for a non-modified alloy and an alloy modified with CuP10 master alloy. Based on the distribution of stresses according to the Huber-Mises-Hencky theory (for a given range of the deflection from 0.1 to 0.3 mm), Wöhler curve was determined for the studied alloy. Based on on microstructural investigations, cracks of primary Si crystals were found, caused by fatigue changes resulting from unilateral pulsating vibrations.

9

Modification of Aluminium-Silicon Near-Eutectic Alloy with Use of Electrolysis of Sodium Salt

Białobrzeski A., Pezda J., Jarco A.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 4

2371--2374

EN

The present work discusses results of preliminary tests concerning the technology of continuous dosage of sodium to a metallic bath from the aspect of modification of EN AC-44200 alloy, through the use of a multiple compound (salt) of sodium. The technology consists in continuous electrolysis of sodium salts occurring directly in a crucible with liquid alloy. As a measure of the degree of alloy modification over the course of testing, the ultimate tensile strength (UTS or Rm) and analysis of microstructure are taken, which confirm the obtained effects of the modification on the investigated alloy. Assurance of stable parameters during the process of continuous modification with sodium, taking into consideration the fact of complex physical-chemical phenomena, requires additional tests aimed at their optimization and determination of a possibility of implementation of such technology in metallurgical processes.

10

Improved Mechanical Properties of Al-Si Alloys by Adding an Extrusion Process to Conventional Processing Method

Han J. Y., Femi O. E., Kilicaslan F., Jeong C. U., Baeg C. H., Hong S. J., Koo J. M.

Archives of Metallurgy and Materials

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2017

|

Vol. 62, iss. 2B

1179--1183

EN

In this study, the mechanical properties of Al-Si alloys was improved by selecting higher Si content and avoiding distortion in Al-Si matrix by adding an extrusion process such that the fabrication processes casting and extrusion were in sequence. Cast billets were extruded at ratios 4:1 and 10:1 to obtained two extruded bars with different processing parameters. The as-extruded samples were characterized and investigated for microstructure and mechanical properties. Optical Microscope was used to examined phase morphologies and microstructures of the extruded Al-Si bars. Mechanical properties were conducted on each sample to study the effectiveness of the additional extrusion process in high Si content Al-Si alloys. The result shows that by increasing the extrusion ratio, the size of the primary Si particle reduces leading to a higher density, better tensile and yield strength compared to the cast billet.

11

Optymalizacja zabiegów rozdrobnienia ziarna i modyfikacji eutektyki w pod- i okołoeutektycznych stopach Al-Si

Saja K.

Prace Instytutu Odlewnictwa

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2016

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Vol. 56, no. 4

351--361

PL

Zabiegi rozdrobnienia ziarna i modyfikacji eutektyki krzemowej w siluminach pod- i okołoeutektycznych należą do ważnych czynników kształtujących ich mikrostrukturę oraz właściwości fizyko-mechaniczne i technologiczne. Z uwagi na ten fakt w publikacji zostały podjęte zadania odpowiedniego, optymalnego doboru dodatków rozdrabniających αAl − roztwór stały oraz modyfikujących eutektykę krzemową (αAl + βSi), w zależności od stopnia eutektyczności układu Al-Si. Wytopy realizowane były w Zakładzie Stopów Metali Nieżelaznych Instytutu Odlewnictwa w Krakowie zgodnie z planem doświadczeń. Otrzymane wyniki badania właściwości mechanicznych (Rm, Rp0,2, A5, Z i HB) poddane zostały obróbce statystycznej. Wyniki te, na podstawie opracowanej interpretacji graficznej, pozwalają w łatwy sposób na właściwy dobór ilości rozdrabniacza (Ti5B1) i modyfikatora krzemu eutektycznego (AlSr10), w zależności od zawartości krzemu (w % wag.) w układzie Al-Si.

EN

The procedures of grain refinement and modification of a silicon eutectic in hypo- and transeutectic silumins belong to important factors shaping their microstructure as well as physico-mechanical and technological properties. Due to this fact, the study attempts to address a proper, optimal, selection of refining additions αAl − a solid solution as well as additions modifying the silicon eutectic (αAl + βSi), depending on the eutecticity degree of the Al-Si system. The melts were realized at the Department of Non-Ferrous Metal Alloys of the Foundry Research Institute in Kraków. according to the experiment schedule. The obtained results of the examinations of the mechanical properties (Rm, Rp0.2, A5, Z and HB) underwent statistical treatment. The results, based on elaborate graphic interpretation, enable an easy selection of the amount of refiner (Ti5B1) and modifier of the eutectic silicon (AlSr10), depending on the silicon content (at wt. %) in the Al-Si system.

12

Charakterystyka tribologiczna stopów Al-Si wykorzystywanych w przemyśle motoryzacyjnym

Walczak M., Pasierbiewicz K.

Autobusy : technika, eksploatacja, systemy transportowe

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2016

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R. 17, nr 11

152--155

PL

Artykuł dotyczy analizy charakterystyki zużycia tribologicznego odlewniczych stopów Al-Si stosowanych w przemyśle motoryzacyjnym. Przedmiot badań stanowiły: AlSi6Cu, AlSi7Mg, AlSi12CuNiMg i AlSi20CuNi. Testy tribologiczne prowadzono w warunkach tarcia technicznie suchego. Badania zrealizowano na tribotesterze typu „ball-on-disc”. Badano współczynnik zużycia i współczynnik tarcia stopów, a ślady zużycia poddano obserwacjom SEM. Ocenę istotności zmian współczynnika zużycia przeprowadzono testem Kruskala-Wallisa. Największą odporność na zużycie w teście odnotowano kolejno dla: AlSi20CuNi > AlSi12CuNiMg > AlSi7Mg > AlSi6Cu.

EN

The paper examines the characteristics of tribological wear of casting Al-Si alloys used in the automotive industry. Tests are performed on the following materials:. AlSi6Cu, AlSi7Mg, AlSi12CuNiMg and AlSi20CuNi. The tribological tests are performed under dry friction conditions. Measurements were performed on „ball-on-disc” tribotester. Were tested wear rate and coefficient of friction of the alloys, the tracks of wear was SEM observation. The evaluation of the significance of changes in wear factor was conducted by Kruskal-Wallis test. The highest resistance to wear in the ball-on-disc test was observed for the tested materials in the following order: AlSi20CuNi > AlSi12CuNiMg > AlSi7Mg > AlSi6Cu.

13

Charakterystyka tribologiczna kompozytu A390/Gr

Walczak M., Bieniaś J., Pasierbiewicz K.

Autobusy : technika, eksploatacja, systemy transportowe

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2016

|

R. 17, nr 11

149--151

PL

Artykuł przedstawia wyniki badań tribologicznych kompozytu A390/Gr (zawierającego cząsteczki grafitu w ilości 5,7% wag.) i jego osnowy AlSi20CuNi. Kompozyt ten znajduje zastosowanie, jako nowoczesny materiał konstrukcyjny w przemyśle motoryzacyjnym, szczególnie na tłoki, tuleje cylindrowe i łożyska ślizgowe. Pomiary współczynnika tarcia wykonano na tribotesterze typu „ball-on-disc” z przeciwpróbkami (ball) w postaci kulek wykonanych ze stali 100Cr6. Badano współczynnik zużycia i współczynnik tarcia próbki, a ślady zużycia poddano obserwacjom SEM. Ocenę istotności zmian współczynnika zużycia przeprowadzono testem U Manna-Whitneya. Odporność na zużycie stopu osnowy i kompozytu zostały poddane analizie porównawczej. Wykazano, że kompozyt zbrojony grafitem charakteryzuje się mniejszym współczynnikiem tarcia i mniejszym zużyciem w porównaniu do osnowy.

EN

The paper presents the results of tribological research on A390/Gr composite (containing graphite particles in the amount of 5.7% wt.%) and on AlSi20CuNi its matrix. This composite is used in automotive industry, particularly for pistons, cylinder liners and slide bearings. Friction coefficient measurements were performed on „ball-on-disc” tribotester with counter-specimen (ball) made of steel 100Cr6. Were tested wear rate and coefficient of friction of the sample, the tracks of wear was SEM observation. The evaluation of the significance of changes in wear factor was conducted by Manna-Whitney U test. It was demonstrated that the composite reinforced with graphite is characterized by lower friction coefficient and lower wear in comparison to the matrix.

14

Effect of silicon content on machinability of AL-SI alloys

Akyüz B.

Advances in Science and Technology. Research Journal

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2016

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Vol. 10, nr 31

51--57

EN

In this study the effect of the change in the amount of Silicon (Si) occuring in Al-Si alloys on mechanical and machinability properties of the alloy was investigated. The change in mechanical properties and microstructure, which depends on the increase in Si percentage, and the effects of this change on Flank Build-up (FBU), wear on the cutting edge, surface roughness, and machinability were also studied. Alloys in different ratios of Si (i.e. 2 to 12 wt %), were employed in the study. The specimens for tests were obtained by casting into metal moulds. The results obtained from experimental studies indicate improved mechanical properties and machinability, depending on the rise in Si percentage in Al-Si alloys. It is also observed that the increase in Si percentage enhanced surface quality.

15

Morphology of intermetallic phases in Al-Si cast alloys and their fracture behaviour

Hurtalova L., Tillova E., Chalupova M., Belan J.

Production Engineering Archives

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2015

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Vol. 6, No. 1

2--5

EN

Applications of Al-Si cast alloys in recent years have increased especially in the automotive industry (dynamic exposed cast, engine parts, cylinder heads, pistons and so on). Controlling the microstructure of secondary aluminium cast alloys is very important, because these alloys contain more additional elements that form various intermetallic phases in the structure. Therefore, the contribution is dealing with the valuation type of intermetallic phases and their identification with using optical and scanning microscopy. Some of the intermetallic phases could be identified on the basis of morphology but some of them must be identified according EDX analysis. The properties of aluminium alloy are affected by morphology of intermetallic phases and therefore it is necessary to study morphology and its fracture behaviour. The present work shows morphology and typical fracture behaviour as the most common intermetallic phases forming in Al-Si alloys.

16

Własności rezystancyjne powłok PVD ze stopów AlSi

Kucharska B., Kowalczyk J.

Elektronika : konstrukcje, technologie, zastosowania

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2015

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Vol. 56, nr 8

48-50

PL

Nowoczesne metody modyfikacji własności i ochrony powierzchni materiałów, do których należy metoda fizycznego osadzania z fazy gazowej (PVD) znalazły zastosowanie w różnych gałęziach przemysłu, w tym w elektronice. Ze względu na silne rozdrobnienie struktury, powłoki metaliczne wytworzone tą metodą posiadają znacznie lepsze własności mechaniczne i odporność korozyjną w porównaniu do stopów wytworzonych metodami konwencjonalnymi. W pracy przedstawiono badania własności elektrycznych powłok Al-Si wykonanych metodą PVD. W procesie magnetronowym rozpylano targety ze stopów pod-, około- i nadeutektycznego. Powłoki badano w różnej temperaturze indukowanej przepływem przez nie prądu elektrycznego. W oparciu o charakterystyki prądowo-napięciowe, wyznaczono rezystancję powłok w każdej z temperatur. Określono wpływ udziału krzemu w powłoce oraz przygotowania stopów na targety (homogenizacja, modyfikacja TiAlB) na rezystancję powłok i ich temperaturę podczas badania.

EN

Modern methods of modification of the properties and protection of material surface, which embrace gaseous phase physical deposition (PVD) methods, arouse the interest of many branches of industry, as well as of electronics. By virtue of their fine-grained structure, metallic coatings fabricated by these methods have superior mechanical properties and corrosion resistance compared to alloys made by traditional technologies. The paper presents a study of the electrical properties and structure of Al-Si coatings made by PVD method. Targets of hypo-, peri- and hyper-eutectic composition alloys, respectively, were sputtered in the magnetron process. The Al-Si coatings under various temperature conditions induced by the flow of electric current through the coatings was examined. Based on the current-voltage parameters, the coatings electrical resistance was determined at specified temperatures. The effects of silicon content in the coating and the preparation of target alloys (homogenization, modification TiAlB) on the electrical resistance of coatings and their temperature during the test was determined.

17

Double Modification Of AlSi9Mg Alloy With Boron, Titanium And Strontium

Lipiński T.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 3

2415--2419

EN

The microstructure of an unmodified AlSi9Mg alloy comprises large primary α phase dendrites, eutectic β phase crystals and eutectic α phase. This composition is responsible for the alloy’s low strength parameters, and it limits the extent of practical applications. The mechanical properties of hypoeutectic silumins can be improved through chemical modification as well as traditional or technological processing. Modification improves the mechanical properties of alloys through grain refinement. This study presents the results of double modification of an AlSi9Mg alloy with strontium, boron and titanium. The influence of the analyzed modifiers on the microstructure and mechanical properties of the processed alloy was presented in graphs. The modification of a hypoeutectic AlSi9Mg alloy improved the alloy’s properties. The results of the tests indicate that the mechanical properties of the modified alloy are determined by the sequence in which the components are introduced to the alloy.

PL

Mikrostruktura niemodyfikowanego stopu AlSi9Mg składa się z dużych dendrytów pierwotnej fazy α, eutektycznych kryształów fazy β i eutektycznej fazy α. Taki skład fazowy jest przyczyną niskiej wytrzymałości stopu, co ogranicza jego praktyczne zastosowanie w praktyce. Właściwości mechaniczne podeutektycznych siluminów można poprawić poddając stop modyfikacji chemicznej, jak również poprzez zastosowanie procesów technologicznych. Modyfikacja poprawia właściwości mechaniczne stopów poprzez rozdrabnianie ziarna. W pracy przedstawiono wyniki podwójnej modyfikacji stopu AlSi9Mg przy użyciu strontu, boru i tytanu. Wpływ badanych modyfikatorów na mikrostrukturę i właściwości mechaniczne obrabianego stopu przedstawiono na wykresach. Modyfikacja podeutektycznego stopu AlSi9Mg poprawiła jego właściwości. Wyniki badań wskazują, że właściwości mechaniczne modyfikowanego stopu zależą od kolejności, w jakiej składniki są wprowadzane do stopu.

18

Ocena własności technologicznych odlewniczych stopów aluminium przy wykorzystaniu Metal Health System

Augustyn B., Stuczyński T.

Rudy i Metale Nieżelazne

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2010

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R. 55, nr 7

436-440

PL

W artykule opisano unikatowe narzędzie pomiarowe przeznaczone dla potrzeb odlewni. Na przykładzie stopu podeutektycznego oraz okołoeutektycznego przedstawiono możliwości wykorzystania zestawu kokil Metal Health System do oceny własności technologicznych odlewniczych stopów aluminium. W rezultacie przeprowadzonych pomiarów można stwierdzić, iż stop o wyższej zawartości krzemu miał lepszą lejność. Natomiast nie zaobserwowano istotnych zmian lejności w zakresie dodanych ilości rozdrabniacza i modyfikatora. Dodatek strontu jedynie ustabilizował te wskazania. Ocena czystości metalu przy wykorzystaniu formy K (K-test), nie ujawniła żadnych dużych wtrąceń, tlenków, pęcherzy gazowych, co może świadczyć o prawidłowym przygotowaniu metalu. Pomiar skłonności do pęknięć na gorąco wykazał, że jedynie stop podeutektyczny z Cu posiada tendencję do pękania. Dodatek Tibalu nie zredukował niekorzystnej skłonności. Wyniki dla poszczególnych próbek wytrzymałościowych otrzymanych w nowej kokili są jednorodne, a dzięki stabilizacji temperatury na poziomie 400 stopni Celsjusza zapewniają lepsze odzwierciedlenie warunków odpowiadających szybkością stygnięcia w stałych odlewach kokilowych. Przy pomocy tzw. Tatur testu określono skurcz dla poszczególnych stopów, oraz oceniono charakter skłonności do tworzenia porowatości.

EN

Paper presents practical usage of Metal Health System of Ingot Moulds in assessment of technological properties of aluminium alloys on example of under and near eutectic alloy. Measurement of castability confirmed that alloy with higher Silicon content shows better castabililty, addition of Strontium stabilizes fluidity index.There was no significant influence on castability after addition of refiner and modificator. Assessment of metal purity using K form (K-test) showed no major inclusions, oxides, gas cavities. Measurement of heat cracking tendency showed that only under eutectic alloy with Cu has tendency for cracking. TiBAl addition didn't reduce this damaging inclination. Results of particular strength samples received in new mould are homogeneous; thanks to temperature stabilization on a level of 400 degrees of Celsius comply with speed of cooling in stable mould casts. Tatur test described shrinkage of particular alloys.

19

Use of barbotage refining of aluminum-silicon alloy to improve mechanical properties of high pressure die castings

Orłowicz A. W., Mróz M., Tupaj M., Betlej J., Płoszaj F.

Archives of Foundry Engineering

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2009

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Vol. 9, iss. 2

41-44

EN

This study presents the research results of the influence that barbotage refining on the mechanical properties of high pressure die casting made of AlSi12S alloy. The operation of refining was conducted in a melting furnace, with the use of an FDU Mini Degasser. Mechanical properties (UTS, YS, Elongation, Brinell Hardness) were assessed on the samples taken from high pressure die castings. The influence of transferring molten metal and the influence of time of keeping molten metal undergoing the refining process on the alloy mechanical properties.

20

Influence of technological factors on eutectic silicon morphology in Al-Si alloys

Skočovsky P., Tillová E., Belan J.

Archives of Foundry Engineering

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2009

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Vol. 9, iss. 2

169-172

EN

From the background about Al-Si alloys modifying from eutectic silicon morphology and mechanical properties relation point of view is at solving of chosen technological problems used structural analysis and Si morphology quantification. There were solved two concrete problems: parameters of solution annealing AlSi9Cu3 alloy and confirming of laser treatment influence on AlSi7Mg0.3 alloy structure. In both cases have material heating caused spheroidization of eutectic silicon. Optimal regime of AlSi9Cu3 alloy (515 oC/4 hrs.) solution annealing was confirmed based on structural analysis, which have achieved fine globular silicon particles segregation and structural changes study at AlSi7Mg0,3 alloy after laser treatment showed improving of mechanical properties, proved also with metallography analysis. Modern methods of structure analysis application enable to spread present knowledge's in area of technological research.