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

The constrained moduli of the γ and γ′ 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 γ and 134 GPa in the γ′ at room temperature, while at 900 °C they are 96 and 90 GPa. Therefore load partitions markedly to the γ′ phase at room temperature but there is little load partitioning at elevated temperatures.