Enhanced ductility and thermal stability of TZM alloys via nanoscale second phase

Abstract

In this study, molybdenum alloy with the nanoscale second phase dispersion distribution (NM-TZM) was prepared by powder metallurgy. Despite maintaining a high yield strength of 893 MPa, the elongation of the as-forged MN-TZM alloy has been increased to 25.3 %. In addition, the recrystallization start temperature of NM-TZM alloy was increased by 100 °C, reaching 1400 °C. The nanoindentation results indicate that the NM-TZM alloy still exhibits a high hardness of 4.40 GPa following annealing at 1400 °C. The addition of nanoscale second phase can improve the ductility and high temperature stability of the alloy by coupling with dislocations and grain boundaries. A new model for the synergistic effect of grain boundaries and intragrains to improve ductility is proposed, which provides insight into the reason behind the high ductility of NM-TZM.