ISSUE 2/2010

/// 02
Franke, M. M.; Hilbinger, R. M.; Heckl, A.; Singer, F.
Effect of thermo physical properties and processing conditions on primary dendrite arm spacing of nickel-base superalloys – numerical approach

This paper presents the results of an investigation on the interrelationship between thermo physical properties, processing conditions and primary dendrite arm spacing for a nickel-base superalloy. The research was realized for CMSX-4, directionally solidified in a Bridgman furnace. For a systematic, fast and cost-efficient investigation numerical methods were applied. The numerical model, composed of thermo physical material data, geometric data and boundary conditions, was calibrated and experimentally validated. Microstructural parameters of the castings are determined for a broad range of processing conditions and varying thermo physical properties to study general influences. The withdrawal speed, the furnace temperature, the enthalpy of fusion, the solidification range, the conductivity and the specific heat were varied accordingly. The primary dendrite arm spacing shows a weak dependency on thermo physical properties; withdrawal speed and furnace temperature have a predominant influence on the dendrite arm spacing.

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