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1

Influence of Rare Earth Sm Addition on Microstructure and Tensile Properties of Al-Si-Cu 319 Alloy

Patel D. N., Sutaria Mayur P.

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 1

25--33

EN

In the present investigation, the influence of addition of the rare earth element samarium (Sm) in different concentrations (0, 0.1, 0.3, 0.5, 0.7 and 0.9wt.%) on the microstructure and tensile properties of the Al-Si-Cu 319 alloy have been evaluated. Microstructural constituents such as SDAS of α-Al and characteristics of eutectic silicon particles were observed by optical microscopy. It was concluded from the findings that Sm addition reduces the size of secondary dendrite arm spacings (SDAS) and altered the morphology of the eutectic silicon particles from needle-like to lamellar and smaller segments. The tensile properties of the Al-Si-Cu 319 alloy improved with the concentration of Sm. It was found that the highest tensile properties were obtained at 0.7wt.% addition of Sm, i.e., 55.5% higher than unmodified 319 alloy. With the further addition of the Sm above 0.7wt.%, it does not improve the tensile properties of the alloy. This can be attributed to the precipitation of the brittle and needle like quaternary Sm-rich intermetallic compounds observed through Scanning electron microscopy.

2

Effect of Zirconium on the Solidification Path and Structural Properties of Commercial AlSi10MgCu Alloys

Hajduch P., Djurdjevic M. B., Bolibruchová D., Simicevic Z.

Archives of Metallurgy and Materials

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2020

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Vol. 65, iss. 2

549--554

EN

Comprehensive understanding of the melt quality is of vital importance for foundry man. The effect of each particular element need to be properly analysed. Therefore, the aim of this paper was to analyse the impact of various content of zirconium on the solidification path and structural characteristics (SDAS, grain size, porosity) of as cast commercial AlSi10MgCu alloys. It has been found that addition of zirconium up to 0.24 wt.% reduce significantly the grains size (from 3.5 mm to 1.2 mm), SDAS (from 57.3 μm to 50.4 μm) and porosity (from 19% to 5%), leading to production of sound cast parts.

3

Effect of Titanium Addition on the Pro-Eutectic and Eutectic Phases of AlSi9 Cast Alloy

Ait El Haj Badiâ, Bouayad Aboubakr, Alami Mohammed

Archives of Metallurgy and Materials

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2020

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Vol. 65, iss. 1

385--391

EN

In this study, the effects of grain size refiner addition and various pre-heating mold temperatures on AlSi9 cast alloy microstructure and solidification have been evaluated. For different process conditions, thermal analysis was performed for all samples and cooling curves were established. Important parameters in liquidus and eutectic Si-phase regions have been calculated usingthe first derivative cooling curves. Secondary Dendrite Arm Spacing (SDAS) variation was also determined. Experimental results question the effectiveness of cooling curve parameters in providing the microstructure data as a function of refinement. The present work shows that the effect of grain refiner addition on the value of SDAS was higher when the solidification time was lower. It indicated that the solidification parameters such as nucleation temperatures of α-Al phase, undercooling temperature and total solidification time were affected by grain refinement. It has been found that the addition of grain refiner affect the eutectic phase formation time. However, it has no effect on the eutectic phase morphology.

4

Analysis of material flow in semisolid state during backward extrusion

Martinkovic Maros

Hutnik, Wiadomości Hutnicze

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2019

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Vol. 86, nr 8

257--259

EN

During of backward extrusion, a cup shape formed piece was created. The flow of material in the wall and bottom is well mathematically described. There is space in the corner of the body where the material flow is not mathematically described. Using the methods of quantitative metallography, the flow of material of eutectic SiAl alloy (silumin) in semisolid state in this area was determined. In a metallographic cut secondary dendritic arm spacings (SDAS) were measured. The junction of the same values for this parameter represented the material flow path.

PL

Wytworzono element o kształcie kubka w procesie przeciwbieżnego wyciskania. Przepływ materiału w ścianie i dnie jest dobrze opisany matematycznie. W rogu ciała jest przestrzeń, w której przepływ materiału nie jest opisany matematycznie. Przy użyciu metod metalografii ilościowej określono płynięcie eutektycznego stopu SiAl (silumin) w stanie półstałym. W badaniach metalograficznych zmierzono odległości wtórnych ramion dendrytytów (SDAS). Połączenie tych samych wartości dla tego parametru reprezentuje drogę płynięcia materiału.

5

The Effect of Nickel on Shaping the Structure of Al-Cu-Mn Alloys

Górny M., Sikora G., Tyrała E.

Journal of Casting & Materials Engineering

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2017

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Vol. 1, no. 1

20--26

EN

This study investigated the effect of nickel on shaping the structure of aluminum alloys of the Al-Cu-Mn type in the “as-cast” condition and after heat treatment according to the T6 procedure. The aluminum alloys of type Al-5%Cu-1%Mn, containing nickel in a range of up to 1.9%, were taken into consideration in this work. Experiments were carried out for thin-walled thickness casting (g = 5 mm) and for reference casting with a wall thickness of g = 35 mm. Metallographic investigations of both the macro- and micro-structure were conducted to estimate the secondary dendrite arm spacing (SDAS), average diameter (dav) of the primary α (Al) grains, and surface fraction of the interdendritic phases (f). Moreover, the degree of dissolution of these interdendritic phases during the solution treatment process was determined. An SEM-EDS analysis was conducted, from which it follows that the addition of nickel at the level of 0.5% changes the un-dissolved particles from a needle-like β-Fe shape to blocky and coagulated. Higher additions of nickel starting from 0.88%) give rise to as many as four phases with higher copper content, the deficit of which results in the smaller strengthening effect of α (Al) dendrites.

6

The fixed-effects analysis of the relation between SDAS and carbides for the airfoil blade traces

Pietraszek J., Szczotok A., Radek N.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 1

235--239

EN

The primary objective was to test a usefulness of the specific fixed-effect model for the analysis of quantitative relationships gathered from the image analysis of the material microstructures. The dataset was obtained from the investigation of turbine blades made from superalloy IN713C. The analysis based on the general linear model resulted in informative plots revealing mutual relationships between secondary dendrite arm spacing and the mean plane section area of carbides in the material. Directions for further research also were obtained.

7

Effect of Alloy Additions on the Structure and Mechanical Properties of the AlSi7Mg0.3 Alloy

Pisarek B. P., Rapiejko C., Szymczak T., Pacyniak T.

Archives of Foundry Engineering

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2017

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Vol. 17, iss. 1

137--142

EN

The study presents the results of the investigations of the effect of Cu, Ni, Cr, V, Mo and W alloy additions on the microstructure and mechanical properties of the AlSi7Mg0.3 alloy. The examinations were performed within a project the aim of which is to elaborate an experimental and industrial technology of producing elements of machines and devices complex in their construction, made of aluminium alloys by the method of precision investment casting. It was demonstrated that a proper combination of alloy additions causes the crystallization of complex intermetallic phases in the silumin, shortens the SDAS and improves the strength properties: Rm, Rp0.2,HB hardness. Elevating these properties reduces At, which, in consequence, lowers the quality index Q of the alloy of the obtained casts. Experimental casts were made in ceramic moulds preliminarily heated to 160 °C, into which the AlSi7Mg0.3 alloy with the additions was cast, followed by its cooling at ambient temperature. With the purpose of increasing the value of the quality index Q, it is recommended that the process of alloy cooling in the ceramic mould be intensified and/or a thermal treatment of the casts be performed (ageing) (T6).

8

Influence of the crystallization condition on Al-Si-Cu casting alloys structure

Dobrzański L. A., Borek W., Maniara R.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 18, nr 1-2

211--214

EN

Purpose: The purpose of this paper is to show the effect of solidification rate on microstructural features, hardness and microhardness of Al-Si-Cu alloys in as cast state. Design/methodology/approach: The main base of the paper is to compare the properties of aluminium cast alloys of ACAlSi7Cu, ACAlSi7Cu2 and ACAlSi7Cu4. Microstructural features were characterised using light optical microscopy. For rapid determination of the parameters: grains size and Secondary Dendrite Arm Spacing - SDAS were used Leica Q-WinTM computer image analyzer. Findings: Increasing the solidification rate increases refines all microstructural features grain size and SDAS. Increasing the solidification rate have an impact on the hardness and microhardness of investigated aluminium cast alloys. Research limitations/implications: In this paper influence of solidification rate on mechanical properties was described. Further investigations should be concentrate on assessment an influence of silicon contents and solidification rate on microstructural features and mechanical properties. Practical implications: The aim of this work is describe the effect of different solidification conditions on changes of microstructure and mechanical properties of ACAlSi7Cu, ACAlSi7Cu2, ACAlSi7Cu4 alloys used to produce the car engine block. Originality/value: The paper contributes to better understanding and recognition an influence of different solidification condition on microstructure and mechanical properties of aluminium alloys.