Abstract
L12-structure Pt3Hf alloy has potential application in the high temperature field due to its higher melting point and superior strength. As a candidate strengthening phase for designing Pt-based superalloys, the improvement of stability and mechanical properties of L12-Pt3Hf is crucial for its application. In this work, the alloying effect on the elastic properties, stacking fault energy, yield behavior and ductility of L12-Pt3Hf are investigated by using the first-principles methods. The results indicate that the dislocation dissociation bounding with a superlattice intrinsic stacking fault (SISF) is energetically favored, thus the yield stress anomaly (YSA) is absence in L12-Pt3Hf. V, Mo and W may change the deformation mode of L12-Pt3Hf, and they have a positive effect on improving the ductility. The analysis of electronic structure reveals that adding alloying elements close to or belonging to half-filled d-orbital is beneficial to improve the ductility of L12-Pt3Hf.
NSTL
Elsevier