Irradiation Damage Independent Deuterium Retention in WMoTaNbV

Area of Science:

• Materials Science
• Nuclear Engineering
• Surface Science

Background:

• High entropy alloys (HEAs) offer excellent radiation resistance and thermal stability.
• Hydrogen interaction with materials is critical for applications like hydrogen storage and fusion energy, posing risks like embrittlement and tritium retention.

Purpose of the Study:

• To investigate deuterium (D) retention and irradiation-induced trapping sites in the high entropy alloy WMoTaNbV compared to bulk tungsten (W).
• To assess the potential of HEAs for hydrogen management in extreme environments.

Main Methods:

• Thermal desorption spectrometry (TDS)
• Secondary ion mass spectrometry (SIMS)
• Elastic recoil detection analysis (ERDA)
• SRIM simulations for damage assessment

Main Results:

• WMoTaNbV retained 90% of implanted deuterium, significantly higher than tungsten's 35%.
• Unlike tungsten, deuterium implantation did not create additional hydrogen traps in WMoTaNbV.
• Calculated damage in WMoTaNbV was 0.24 dpa with maximum damage at 90 nm depth.
• An effective trapping energy for deuterium in WMoTaNbV was determined to be approximately 1.7 eV, with emission near 700 °C.

Conclusions:

• High entropy alloy WMoTaNbV exhibits substantial deuterium retention capacity without forming new traps upon irradiation.
• The findings highlight WMoTaNbV's potential for hydrogen storage and underscore the need to understand its deuterium behavior in fusion reactor applications.