Elastic moduli and load partitioning in a single-crystal nickel superalloy

The constrained moduli of the gamma and gamma' phases of the Ni superalloy CMSX-4 have been determined using in situ neutron diffraction. The elastic moduli of the isolated phases fitted using a model are found to be E([100]) = 103 GPa in the gamma and 134 GPa in the gamma' at room temperature, while at 900 degrees C they are 96 and 90 GPa. Therefore load partitions markedly to the gamma' phase at room temperature but there is little load partitioning at elevated temperatures. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.