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Investigation of selected thermo-physical properties in the Co-based superalloy: Experiment and application study

Kasala J., Mäsiar H., Pernis I.

Archives of Foundry Engineering

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2010

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Vol. 10, iss. 1 spec.

203--206

EN

Thermo-physical properties are the critical input parameters in computational models of solidification and casting simulations. In thermodynamics, the enthalpy is quotient of thermodynamic potential of a system, which can be used to calculate the useful work obtainable from a closed thermodynamic system under constant pressure. Differential thermal analysis has been used to study melting and solidification paths in the cobalt based superalloy FSX-414. The temperature enthalpy curve was determined from differential thermal analysis curves obtained from solidification curves. A solidification simulation of a cobalt base multi-component alloy casting was carried out to predict cooling and shrinkage porosity in the casting of a turbine engine vane segment. The effect of latent heat on the heat transfer calculation was considered by enthalpy method.

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Influence of gating system design on tensile properties of AlSi7Mg0.3 alloy

Kasala J., Pernis R., Čaplovič L'.

Archives of Foundry Engineering

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2010

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Vol. 10, iss. 1 spec.

117--120

EN

Aluminium-silicon castings are typically produced by gravity casting. Bottom gated systems are usually required if surface turbulence is to be eliminated. Latest research has demonstrated, that for every liquid metal there is critical velocity above which the surface will fold over and entrain itself in the bulk of the metal. Therefore the strength properties the aluminium castings are largely determined by microstructural defects, particularly pores and oxide films which are created by surface turbulence. The purpose of this paper is to investigate tensile properties and microstructure of aluminium alloy in a casted state two different designs of gating system. The first is the usual bottom gating system and the second is novel design of gating system named a vortex-gate introduced by Campbell [1]. The results of the mechanical tests revealed that there is a small improvement in ultimate tensile strength for vortex-gate design of pouring system. The oxide film defects were observed in microstructure of a sample taken from poured casting by using the bottom gated system.

3

Effect of polyethylene oxide on properties of bentonite foundry mixtures

Mäsiar H., Kasala J., Kaloforov N.

Archives of Foundry Engineering

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2007

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Vol. 7, iss. 1

69-72

EN

Very small quantities of polyethylene oxide (PEO) with molecular weight of 600,000 exhibit a non-additive effect of increased permeability that is higher in higher compaction energies (19.62 J). Increased permeability has been proven at such small PEO quantities as 0.0365 %-wt., 0.073 %-wt., and 0.1 %-wt. The above mentioned very small PEO quantities result in slightly increased bondability. It is estimated that PEO effect will find application in metal casting at lower melting temperatures.