Adhesion of voids to bimetal interfaces with non-uniform energies.
Interface engineering has become an important strategy for designing radiation-resistant materials. Critical to its success is fundamental understanding of the interactions between interfaces and radiation-induced defects, such as voids. Using transmission electron microscopy, here we report an interesting phenomenon in their interaction, wherein voids adhere to only one side of the bimetal interfaces rather than overlapping them. We show that this asymmetrical void-interface interaction is a consequence of differing surface energies of the two metals and non-uniformity in their interface formation energy. Specifically, voids grow within the phase of lower surface energy and wet only the high-interface energy regions. Furthermore, because this outcome cannot be accounted for by wetting of interfaces with uniform internal energy, our report provides experimental evidence that bimetal interfaces contain non-uniform internal energy distributions. This work also indicates that to design irradiation-resistant materials, we can avoid void-interface overlap via tuning the configurations of interfaces.
Los Alamos National Laboratory, Los Alamos, NM 87545, USA.|Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences.
Shijian
S
Zheng
Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
Shuai
S
Shao
Los Alamos National Laboratory, Los Alamos, NM 87545, USA.|School of Energy Research, Xiamen University, Xiamen 361005, China.
Jian
J
Zhang
Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
Yongqiang
Y
Wang
Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Michael J
MJ
Demkowicz
Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
Irene J
IJ
Beyerlein
Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
Nathan A
NA
Mara