Evaluation of oxide dispersion strengthened (ODS) molybdenum and molybdenum–rhenium alloys

Abstract

Oxide dispersion strengthened (ODS) molybdenum alloys being developed for high temperature applications possess excellent high temperature strength and creep resistance. In addition they exhibit a ductile-to-brittle transition temperature (DBTT) in the worked and stress-relieved condition under longitudinal tensile load well below room temperature. However, in the recrystallized condition, the DBTT may be near or above room temperature, depending on the volume fraction of oxide dispersion and the amount of prior work. Dilute rhenium additions (7 and 14 wt%) to ODS molybdenum were evaluated to determine their effect on low temperature ductility. The addition of 7 wt% rhenium to the ODS molybdenum did not significantly enhance the mechanical properties. However, the addition of 14 wt% rhenium to the ODS molybdenum resulted in a DBTT well below room temperature in both the stress-relieved and recrystallized condition. Additionally, the tensile strength of ODS Mo-14 Re is greater than the base ODS molybdenum at 1000–1250°C.