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1

The influence of graphite particles on supercooling of composite suspension

Łągiewka M., Konopka Z., Zyska A.

Archives of Foundry Engineering

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2007

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Vol. 7, iss. 2

139-142

EN

The work presents the solidification kinetics of a composite suspension with graphite particles dispersed in AlMg10 alloy matrix during its flow along a runner. The temperature field for investigated materials has been determined by measuring the suspension temperature values during flow and solidification in the elongated runner-like mould cavity. The influence of the quantity of ceramic particles on the temperature of the solidification beginning has been shown, and by the same its influence on the supercooling of the flowing composite suspension. Differences between the supercooling values for matrix alloy and for composites have been revealed. The obtained results have been interpreted pointing to the influence of graphite particles on activating the nucleation and change of the heat exchange conditions between the flowing suspension and the mould wall.

2

The influence of graphite particles on solidification of composite suspension during flow

Konopka Z., Łągiewka M., Zyska A.

Archives of Foundry Engineering

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2007

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Vol. 7, iss. 2

135-138

EN

The measurements concerning the temperature field of the composite suspension with AlMg10 alloy matrix reinforced with graphite particles during its flow in a runner-like mould cavity have been performed for the purpose of investigating the influence of the graphite particles on the solidification kinetics. Applying the derivative differential thermal analysis method, the kinetics of solidification heat release has been calculated for examined composites. The time-dependent quantity of solid phase crystallized over the period of flow has been determined on this basis. The dependence of the solid phase quantity upon the momentary length of the experimental casting has apportioned the length of the solidification zone in the casting and the critical fraction of solid phase at which the flow stops. The solidification zone is longer and the critical fraction of solid phase at the stream front is lower for composite containing 10% of graphite particles than for the one with 20% of graphite. The composite reinforced with 20% of graphite particles flows at a significantly lower rate and exhibits reduced castability as compared with the composite with 10% of graphite. It is caused by the higher solidification rate in the initial stage of the process. The obtained results allow for supposing that graphite particles intensify composite solidification by changing the kinetics of the process.

3

The distinction of the fine suspension flow from the coarse mixture flow by measuring of the pressure loss on a horizontal pipe

Tarjan I., Faitli J.

Gospodarka Surowcami Mineralnymi

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1998

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T. 14, z. 3

61-69

EN

The paper present the method of characterisation of suspension flow on a pipe (fine or coarse grained) based on the measured pressure loss as a function of flow velocity on a horizontal pipe. The characteristic of this function is dependent on grain-size suspension which is transported. For coarse grained and mixed suspension that function is featured by its hyperbolic character, whereas for fine grained it is a horizontal linear curve parallel to velocity axis. It was evidenced by experimental correlation between distinction of pressure loss and flow velocity for both mixed and fine grained suspension.

PL

W pracy przedstawiono, poprzez pomiar względnej różnicy strat ciśnienia cieczy nośnej i zawiesiny, sposób określenia rodzaju zawiesiny przepływającej w rurze (drobno- czy gruboziarnista) w funkcji prędkości przepływu w poziomej rurze. Charakter tej funkcji jest zależny od uziarnienia transportowej zawiesiny. Dla zawiesin gruboziarnistych i mieszanych jest to zależność hiperboliczna, dla zawiesin drobnoziarnistych jest to natomiast linia prosta równoległa do osi prędkości. Dla poparcia tej tezy podano doświadczalną zależność względnej różnicy strat ciśnienia od prędkości przepływu dla zawiesiny mieszanej oraz zawiesiny drobnoziarnistej.