Structural responses of metallic glasses under neutron irradiation

Abstract

Seeking nuclear materials that possess a high resistance to particle irradiation damage is a long-standing issue. Permanent defects, induced by irradiation, are primary structural changes, the accumulation of which will lead to structural damage and performance degradation in crystalline materials served in nuclear plants. In this work, structural responses of neutron irradiation in metallic glasses (MGs) have been investigated by making a series of experimental measurements, coupled with simulations in ZrCu amorphous alloys. It is found that, compared with crystalline alloys, MGs have some specific structural responses to neutron irradiation. Although neutron irradiation can induce transient vacancy-like defects in MGs, they are fully annihilated after structural relaxation by rearrangement of free volumes. In addition, the rearrangement of free volumes depends strongly on constituent elements. In particular, the change in free volumes occurs around the Zr atoms, rather than the Cu centers. This implies that there is a feasible strategy for identifying glassy materials with high structural stability against neutron irradiation by tailoring the microstructures, the systems, or the compositions in alloys. This work will shed light on the development of materials with high irradiation resistance.

Correlation between positron annihilation lifetime and photoluminescence measurements for calcined Hydroxyapatite

“…The positron lifetime spectra of the annealed hydroxyapatite samples can be separated into two components: an intermediate-lived component (τ 1 ) and a long-lived component (τ 2 ) with intensities I 1 and I 2 , respectively 57 , 58 . The τ 1 component is attributed to the annihilation of free positrons and para-positronium (p-Ps), while the τ 2 component is attributed to the annihilation of ortho-positronium (o-Ps) pick-off annihilation, which depends on the size of the free volume defect.…”

Structural characterization of newly-developed Al79Ni5Fe5Y11 and Al79Ni11Fe5Y5 alloys with amorphous matrixes

“… 29 , neutron radiation is useful for studying bulk materials. According to literature data 30 , 31 , the amorphous structure of metallic glasses should make them resistant to irradiation. Yang et al 30 studied the structural responses of ZrCu metallic glasses under neutron irradiation and did not observe the formation of any crystalline phase, even though they confirmed its presence by synchrotron-based high-energy X-ray diffraction.…”

“…According to literature data 30 , 31 , the amorphous structure of metallic glasses should make them resistant to irradiation. Yang et al 30 studied the structural responses of ZrCu metallic glasses under neutron irradiation and did not observe the formation of any crystalline phase, even though they confirmed its presence by synchrotron-based high-energy X-ray diffraction. However, in the same article 30 , the mechanisms of neutron irradiation that damaged the microstructure of amorphous alloys remained elusive.…”

“…Yang et al 30 studied the structural responses of ZrCu metallic glasses under neutron irradiation and did not observe the formation of any crystalline phase, even though they confirmed its presence by synchrotron-based high-energy X-ray diffraction. However, in the same article 30 , the mechanisms of neutron irradiation that damaged the microstructure of amorphous alloys remained elusive. In this study, the melt-spun ribbons likely had a heterogeneous structure.…”

A Review of Self-healing Metals: Fundamentals, Design Principles and Performance

“…Liang et al investigated the structural evolution of amorphous ZrCu binary alloys and found that the vacancy-like defects induced by neutron irradiation were fully annihilated after a structure relaxation by the rearrangement of free volume, demonstrating the self-healing effect. Moreover, the free volume rearrangement strongly depended on the constituent elements, which implied that the composition design was essential to realize the self-healing mechanism [70]. This group further discovered the self-healing of irradiation-induced vacancies in amorphous-nanocrystalline ZrCu alloy.…”