|About this Abstract
||2020 TMS Annual Meeting & Exhibition
||Refractory Metals 2020
||Performance of Niobium and Molybdenum Alloys for High Temperature Sensing Applications
||Scott Riley, Beck Perrine, Ember Sikorski, Lan Li, Richard Skifton, Brian Jaques
|On-Site Speaker (Planned)
Niobium, molybdenum, and their alloys are often considered for applications in extreme environments where corrosion resistance and high temperatures are required. The Idaho National Laboratory has developed thermocouples comprised of phosphorous-doped niobium and lanthana-doped molybdenum thermoelements, an alumina insulation, and a niobium sheath. Prior to operation, the thermocouples undergo a preliminary heat treatment (above the maximum service temperature) in order to stabilize the emf signal. Herein, a study was conducted to evaluate the effects of the stabilization heat treatment (time, temperature, and process gas) on the mechanical properties, microstructure, and chemical stability of the system. A design of experiments was performed to determine the impact of the process variables on thermocouple performance. The grain size of the sheath increased with increasing temperature and time while the ductility decreased with increasing oxygen concentration in the process gas. The chemical stability of each component was studied and will be discussed in detail.
||Planned: Supplemental Proceedings volume