Anisotropic creep modelling of the single crystal superalloy SRR99

The starting point is a uniaxial non-linear rheological model, which performs the essential properties of the uniaxial behaviour under different loadings, such as monotonous and cyclic creep and LCF. A tensorial generalization of the uniaxial differential equations is derived by a projection method, which gives a general three-dimensional model obeying the crystal symmetries, An identification for the single crystal superalloy SRR99 at 760 degrees C has been made for tensile creep tests in different orientations. The model can be used to determine the creep behaviour of structural elements such as bars, torsional shafts or turbine blades.