A phase field modeling based study of microstructure evolution and its influence on thermal conductivity in polycrystalline tungsten under irradiation

作者：Wang Hao; Biswas Sudipta; Han Yousung; Tomar Vikas^*

来源：Computational Materials Science, 2018, 150: 169-179.

DOI：10.1016/j.commatsci.2018.03.070

• Phase field modeling
• Microstructure
• Irradiation
• Void evolution
• Thermal conductivity

In this work, we study effects of neutron irradiation and elastic tensile loading on microstructure evolution in polycrystalline tungsten by using a phase field modeling based approach. The proposed model involves the interaction of point defects with grain boundaries (GBs), thermal resistance of GBs, and voids. The void evolution analysis shows that the elastic energy field affects the shape and growth rate of voids. The overall trend of porosity evolution during irradiation follows the Johnson-Mehl-Avrami-Kolmogorov (JMAK) equation. Voids nucleation and growth can reduce both elastic strain energy and chemical free energy in the system. In addition, increase of porosity could significantly degrade the effective thermal conductivity of analyzed tungsten polycrystalline microstructures. The observations comply with the predictions from the theoretical models.

• 出版日期2018-7