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Research of the New Laboratory Methodology for Measuring the Disintegration of Mixtures with Inorganic Binders Hardened by Dehydration

Bruna Marek, Vasková Iveta, Mednanský Martin, Delimanová Petra

Archives of Foundry Engineering

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2024

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Vol. 24, iss. 1

80--87

EN

The paper deals with the possibilities of using alkali silicate based inorganic binders for automotive industry aluminium castings production. In recent years, inorganic binders are coming back to the foreground and their manufacturers are developing new processes, which are starting to progressively supersede organic binder systems. Paper describes known knowledge about classic alkali silicate binders with focus on hardening processes and on improving their technological properties. Trends from the area of development and the use new alkali silicate based inorganic binders are also shortly described. As part of the experimental work, specific methods of producing samples were developed, with the help of which properties such as disintegration were subsequently evaluated by measuring abrasion and residual strengths. Characteristics such as residual compressive strength or shear strength at different thermal loads were also evaluated. When comparing the laboratory results with the results of de-coring in real conditions, a high degree of correlation was achieved, which makes it possible to determine the optimal recipe/procedure for the production of geometrically complex cores.

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Influence the Composition of the Core Mixture to the Occurrence of Veinings on Castings of Cores Produced by Cold-Box-Amine Technology

Delimanová Petra, Vasková Iveta, Bartošová Marianna, Hrubovčáková Martina

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 3

947--953

EN

The main problem in the cores production by cold-box method is the occurence of surface defects due to the tension generated by thermal expansion of the silica sand. One of the possibilities of eliminination is exchange of silica sand from another location. Another interesting factor is the type of used binder and its amount. However, even these measures donʹt guarantee sufficient quality. Foundries most often solve this problem by adding expensive additives to the core mixture. Foundries may have a dilemma in choosing the right additive. The aim of this paper was to investigate the effect of silica sand from two different locations, the effect of dosing the amount of binder and the addition of several types of commonly available additives on the quality of casting cavities. For this purpose, a total of 11 differently composed core sand mixtures were prepared, but only one of these mixtures was successful.

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Optimization of a Gating System by Means of Simulation Software to Eliminate Cold Shut Defects in Casting

Šabík Vladimír, Futáš Peter, Pribulová Alena, Delimanová Petra

Journal of Casting & Materials Engineering

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2021

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Vol. 5, no. 1

1--4

EN

The current trend in foundries is to achieve the production of high quality and competitive cast components. The innovation and optimization of current processes is a necessary element to achieve this goal. With the help of numerical simulations, it is possible to replace financially demanding and time-consuming experiments in real conditions with simulations that can reliably represent foundry process using computer technology. By a detailed analysis of the simulation results, we can predict various risks that could negatively affect the production process. This article monitors the influence of changes in the design of the gating system on the surface quality of a clutch wheel casting made of ductile iron, in the production of which two models of the gating system for casting were constructed in CAD software. Verification of gating systems was performed using the simulation software NovaFlow & Solid. The aim of the design change of the gating system is to reduce the amount of liquid metal used per casting, which can have a significant economic impact on industrial production. For this purpose, several simulations of the gating system of the casting were performed, while 2 which are the most representative for the mentioned problem were selected for the needs of the article. The main task of the simulation was to set the cellular network and conditions as close as possible to the reality of casting and the subsequent design and modification of the gating system.