Commercial nickel-base superalloys for aeroengine applications are often produced by directional solidification or are cast in single crystal form particularly, for use in the high temperature and high stress environment experienced by HP turbine blades. The impact of single crystal turbine blades in facilitating more efficient engine operation has resulted from significant increases in creep ductility and retention of creep strength to higher temperatures that have led to improved thermal fatigue behaviour and increased engine operating temperatures. However, the anisotropic characteristics of single crystal superalloys are not yet fully understood and it is unlikely that the full potential of these materials has yet been realised. It is unrealistic to compile a database of mechanical properties that encompasses all possible service conditions and crystal orientations; rather it is necessary to develop a rational basis for interpolation and some extrapolation of a limited database that both incorporates material anisotropy and can be interfaced with advanced design procedures.
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