Hard Materials Seminar - "Hydrogen effect on the kink-pair mechanism in tungsten"
- Sponsor
- Materials Science and Engineering Department
- Speaker
- Hyoungryul Park
- Contact
- Bailey Peters
- bnpeters@illinois.edu
- Originating Calendar
- MatSE Hard Materials Seminar Calendar
Tungsten (W) exhibits exceptional physical properties, including a high melting point, radiation resistance, and excellent thermal conductivity, making it a highly attractive plasma-facing material. However, concerns exist about the hydrogen-rich environments of fusion reactors that can cause material degradation. As the solute strengthening mechanism explains, hydrogen as a solute can hinder dislocation motion by dragging or pinning it. In contrast, hydrogen-induced softening can result from increased dislocation nucleation or enhanced kink-pair activation rates. This talk will focus on the kink-pair activation enthalpy barrier change in different hydrogen positions around a single screw dislocation, varying the applied stress. Molecular dynamics simulation is used to find the minimum energy path of each case. Notably, the results show that there are certain positions where the enthalpy barrier of kink-pair activation is reduced, while other spots show an increased enthalpy barrier.