Published online by Cambridge University Press: 01 February 2011
In this work were evaluated the microestructural characteristics by Optical Microscopy (OM) and Scanning Electron Microscopy (SEM) of the intermetallic γ'(liquation, coarsening and decomposition) in the Inconel 939 alloy after 40000 hours and 850–900°C aging operation conditions. The alloy was vacuum conventional cast. The results show that the liquation phenomena take place in eutectics γ-γ' which are present mainly in the core of the dendritic arms and in the coarse films of carbides along the grain boundaries (GB), the γ' particles change their original morphology of ordered cuboids of 320nm to disordered and coarse cuboids of 1.2μm, carbides show a morphology change from the original dispersed particles into a coarse continuous films and particles Chinese script type, this affects adversely the mechanical properties such as creep. The results of this evaluation allow to determine the main microestructural damage mechanisms which experiment some components such as blades at high temperatures in industrial conditions.