Correlation between mechanism of ordering transformation and microstructure of interfaces in Ni-Cr-W superalloys

It is found that the microstructure of interfaces between superlattices and matrix correlates perfectly with the mechanism of ordering transformation. The mechanism of continuous ordering makes the ordering degree from the center of the superlattice to interface to surrounding disordered matrix become increasingly weaker, leading to an obscure interface which can be regarded as a transition region. In contrast, the mechanism of nucleation and growth makes the whole region of the superlattice completely ordered superstructure, resulting in a sharp interface between superlattice and matrix. The mechanism of ordering transformation can be identified by the microstructure of interface.