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Influence of Remelting AlSi9Cu3 Alloy with Higher Iron Content on Mechanical Properties

Matejka M., Bolibruchova D.

Archives of Foundry Engineering

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2018

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Vol. 18, iss. 3

25--30

EN

The paper deals with influence of multiple remelting on AlSi9Cu3 alloy with higher iron content on chosen mechanical properties. Multiple remelting may in various ways influence mechanical, foundry properties, gas saturation, shrinkage cavity, fluidity etc. of alloy. Higher presence of iron in Al-Si cast alloys is common problem mainly in secondary (recycled) aluminium alloys. In Al-Si alloy the iron is the most common impurity and with presence of other elements in alloy creates the intermetallic compounds, which decreases mechanical properties. Iron in the used alloy was increased to about 1.4 wt. %, so that the influence of increased iron content can be investigated. In the paper, the effect of multiple remelting is evaluated with respect to the resulting mechanical properties in cast state, after the heat treatment (T5) and after natural aging. From the obtained results it can be concluded that the multiple remelting leads to change of chemical composition and affect the mechanical properties.

2

Experimental and Simulation Tests on the Impact of the Conditions of Casting Solidification from AlSi9Cu3 Alloy on their Structure and Mechanical Properties

Hajkowski J., Ignaszak Z.

Archives of Foundry Engineering

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2018

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Vol. 18, iss. 1

167--175

EN

The impact of casting conditions on microstructure a and mechanical properties was described, especially for cast products from AlSi9Cu3 alloy. Particular attention was paid to the parameters of dendritic structure: DAS 1 and DAS 2. Selected mechanical properties (by static tension test) of test castings made using basic technologies of casting: GSC - gravity sand casting, GDC - gravity die-casting and HPDC - high-pressure die-casting, are presented for cast-on test bars and cast separately. Casts were made of the same alloy AlSi9Cu3. Fractures and the zone near the fracture (after static tension test) was subjected to VT - visual tests, PT - penetration tests and metallographic tests. The condition of porosity (fracture zone) was also assessed. The analysis of virtual results was performed using the NovaFlow & Solid system together with the database and they were compared to experimental tests. This way of validation was applied in order to assess the correlation between the local rate of cooling and the size of DAS for GSC, GDC and HPDC technologies. Finally, the correlation between the parameters of structure and mechanical properties with regard to the impact of porosity was signalized.

3

The Microstructure of AlSi9Cu3 Alloy after Different Stages of Liquid Metal Preparation

Poloczek Ł., Dybowski B., Łuszczak M., Kiełbus A.

Archives of Foundry Engineering

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2015

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Vol. 15, iss. 1 spec.

89--92

EN

Aluminium alloys are one of the most important casting alloys. Among them, the Al-Si alloys comprise perhaps the most important group – about 80% of the aluminium casts are made of them. These materials are characterized by a very good technological properties, good corrosion resistance and tribological properties. Their main disadvantage is, however, presence of the massive, brittle silicon crystals. They significantly affect alloys mechanical properties. Liquid metal treatment is essential for modification of Al-Si eutectic structure. The following work presents results of the research on the microstructure of the AlSi9Cu3 alloy after different stages of liquid metal preparation. Three casting processes have been conducted, chemical composition of the material in each case was in agreement with EN 1706 specification. During each casting process, three specimens were gravity cast: first, made from pure ingots; second, after the scrap addition and third one after the liquid metal treatment. Qualitative and quantitative evaluation of the microstructure was done on each specimen. Specimens cast from pure ingots are characterized by a refined Al-Si eutectic microstructure. After scrap addition, the silicon crystals became morphology of the massive platelets. What is more, intermetallic phases observed within the structure posses different morphologies after different stages of liquid metal preparation. After scrap addition, increased gas porosity was observed. Liquid metal treatment reduced slightly the formation of gas pores.