Paper Title:

Effect of Thermophysical Properties and Processing Conditions on Primary Dendrite Arm Spacing of Nickel-Base Superalloys – Numerical Approach

Periodical Advanced Materials Research (Volume 278)
Main Theme Euro Superalloys 2010
Edited by M. Heilmaier
Pages 156-161
DOI 10.4028/www.scientific.net/AMR.278.156
Citation Martin M. Franke et al., 2011, Advanced Materials Research, 278, 156
Online since July, 2011
Authors Martin M. Franke, Michael Hilbinger, Astrid Heckl, Robert F. Singer
Keywords Investment Casting, Numerical Modeling, Primary Dendrite Arm Spacing, Solidification Rate, Superalloy, Temperature Gradient
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Abstract

This paper presents the results of an investigation on the interrelationship between thermophysical 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 finite element models were applied. The numerical model, composed of thermophysical material data, geometric data and boundary conditions, was calibrated and experimentally validated. Microstructural parameters of the castings were determined for a broad range of processing conditions and varying thermophysical properties in order to study general influences. Withdrawal speed, furnace temperature, enthalpy of fusion, solidification range, heat conductivity and specific heat were varied accordingly. The primary dendrite arm spacing is predominantly influenced by withdrawal speed and furnace temperature, but shows only a weak dependency on thermophysical properties.