During the manufacturing of investment casting of turbine blades from single crystal superalloys, recrystallisation can potentially occur during subsequent heat treatment. If it is the case, introduction of grain boundary can degrade the fatigue and creep life of the components. Therefore scrappage rate might be increased. In this work, thermo-mechanical modelling along with experimental validation is presented to predict the plastic strain level which proceeds the driving force of recrystallisation. The model indicated that the induced strain in the metal increases with the shell thickness, and in some geometries, with the solidifi cation height. Negligible plastic strains were predicted in a solid casting with no stress concentration features. However, as the geometry became more complex by reducing the casting cross-section, by the insertion of a core and introduction of stress concentration features, the induced plastic strains increased signifi cantly. According to the modelling a maximum plastic strain of 2.5 per cent was induced during casting of a cored analogue casting (1.5 mm wall thickness) that recrystallised after solution heat treatment. Experimental work is critically compared
with modelling.
