PT  - JOURNAL ARTICLE
AU  - Chen, Di
AU  - Li, Nan
AU  - Yuryev, Dina
AU  - Baldwin, J. Kevin
AU  - Wang, Yongqiang
AU  - Demkowicz, Michael J.
TI  - Self-organization of helium precipitates into elongated channels within metal nanolayers
AID  - 10.1126/sciadv.aao2710
DP  - 2017 Nov 01
TA  - Science Advances
PG  - eaao2710
VI  - 3
IP  - 11
4099  - http://advances.sciencemag.org/content/3/11/eaao2710.short
4100  - http://advances.sciencemag.org/content/3/11/eaao2710.full
SO  - Sci Adv2017 Nov 01; 3
AB  - Material degradation due to precipitation of implanted helium (He) is a key concern in nuclear energy. Decades of research have mapped out the fate of He precipitates in metals, from nucleation and growth of equiaxed bubbles and voids to formation and bursting of surface blisters. By contrast, we show that He precipitates confined within nanoscale metal layers depart from their classical growth trajectories: They self-organize into elongated channels. These channels form via templated nucleation of He precipitates along layer surfaces followed by their growth and spontaneous coalescence into stable precipitate lines. The total line length and connectivity increases with the amount of implanted He, indicating that these channels ultimately interconnect into percolating “vascular” networks. Vascularized metal composites promise a transformative solution to He-induced damage by enabling in operando outgassing of He and other impurities while maintaining material integrity.