Characterizing the effects of hot isostatic pressing on IN713C superalloy blade microstructure by electron backscatter diffraction

The integrity of turbine blades is essential for the safe operation of jet engines. Thus, the mechanical properties, especially creep resistance and fatigue strength at high temperatures, must be thoroughly optimized. In particular, it has previously been observed that the mechanical properties of blades depend on the microstructure and porosity resulting from the casting process. To decrease the internal porosity generated by investment casting, hot isostatic pressing can be applied. This paper aims to evaluate the effects of hot isostatic pressing on the microstructure of IN713C alloy blades. Two variants of hot isostatic pressing treatment, differing in pressure, were carried out, and each resulted in lowered porosity. Microstructural investigations, performed using scanning electron microscopy and electron backscatter diffraction revealed significant changes of γ′ particles and high strain intensity in the surface layer of the blades after hot isostatic pressing treatment.