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Study of Si morphology in AlSi21CuNiMg cast alloy using col our and deep etching

Tillová Eva, Chalupová Mária, Kuchariková Lenka, Bonek Mirosław, Uhríčik Milan, Pastierovičová Lucia

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2023

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Vol. 71, nr 2

art. no. e144618

EN

The effect of possible modification and refining effect of Al-Cu-P-based pre-alloy combined with Fe on the microstructure and the silicon morphology change in hypereutectic Al-Si cast alloy was studied. The samples in the as-cast state were observed by optical and scanning electron microscopy with energy-dispersive X-ray spectroscopy. The 3D morphology of both primary and eutectic silicon was observed by using colour and deep etching in detail. The results showed that the AlCu19P1.4 pre-alloy (1.07 wt.%) combined with the addition of Fe (0.02 wt.%) has a significant effect on the change of the amount, size and morphology of primary Si. This is significantly refined and changes the shape from a coarse irregular star-shaped, polyhedral, or plate-like shape to a fine polyhedral shape. The average size of the primary Si is reduced by about of 78 % from 135 μm to 28 μm and the number of primary Si particles increased from 7.4 to 237. No change in the morphology of the eutectic Si was observed; a refinement of the structure from a coarse needle/plate-like to a fine plate-like structure was seen. The depth etching method using HCl was very effective in the study of the 3D silicon morphology observed, which could be observed in detail without the presence of artefacts.

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Evaluation of the Effect of External Conditions During Crystallization and Solidification on the Final Structure of AlSi7Mg

Radkovský Filip, Gawronová Martina, Kroupová Ivana

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 1

118--123

EN

Abstract The paper deals with the possibilities of influencing the final microstructure of aluminium alloy castings by changing the external conditions of crystallization and solidification. Aluminum alloys, especially Al-Si alloys, are nowadays one of the most used non-ferrous metal alloys, especially due to their mass application in the automotive field. It is in this industry that extreme emphasis is placed on the quality of cast parts with regard to safety. For this reason, a key production parameter is the mastery of the control of the resulting microstructure of the castings and the associated internal quality, which is subject to high demands defined by international standards. The aim of the experiment of this paper is to evaluate the effect of different preheating of the metal mould on the resulting structure and hardness of test castings made of AlSi7Mg0.3 material. The hardness measurement will be evaluated on a hardness tester. The parameter SDAS, Microporosity, Content of excluded eutectic will be evaluated. Dependencies will be found and plotted.

3

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.

4

Influence of grain refinement on the structure of silumin AlSi7

Romankiewicz F., Romankiewicz R., Reif W.

International Journal of Applied Mechanics and Engineering

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2010

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Vol. 15, no 2

451-455

EN

The results of grain refinement of silumin AlSi74 with additives of AlB4 and AlTi6 are shown. It is found that grain refinement has a favorable influence on the structure and mechanical properties of the alloy tested.

5

New high materials for machinery and foundry devices

Pietrowski S.

Archives of Metallurgy and Materials

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2010

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Vol. 55, iss. 3

905-914

EN

This paper presents the details rules of material selection predicted for machine parts. Hardness of most applied materials and layers manufactured by PVD method were given. The basic characteristics of new materials selected from alloys group: iron, cooper, aluminum were presented. Revealed its high wear resistance, corrosion resistance and significant mechanical properties.

PL

W pracy przedstawiono uszczegółowione zasady wyboru materiału na części maszyn, podano twardość najczęściej stosowanych materiałów i powłok osadzanych metodami PVD. Przedstawiono podstawową charakterystykę nowych materiałów z grupy stopów: żelaza, miedzi i aluminium. Wykazano ich wysoka odporność na zużycie, korozje oraz znaczne własności wytrzymałościowe.