Grain size threshold for enhanced irradiation resistance in nanocrystalline and ultrafine tungsten

El-Atwani, Osman; Hinks, John; Greaves, Graeme; Allain, Jean Paul; Maloy, S.A.

doi:10.1080/21663831.2017.1292326

Cited by 99 publications

(37 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Here, we present a detailed study investigating the radiation tolerance to bubble formation under low energy (2 keV). Implantation of He + at a high temperature (1223 K) (similar conditions to previous SPD work [15]) of the equiaxial nanocrystalline tungsten with an average grain-size 85 nm (referred to as NCW herein) was formed by magnetron deposition, and the tungsten-TiC (1.1%) (labelled as W-TiC (1.1%)) formed by hot iso-static pressing of tungsten powders with TiC dispersoids. The experiments were performed in-situ within the transmission electron microscope (TEM) in the MIAMI-2 system (Microscope and Ion Accelerators for Materials Investigations) at the University of Huddersfield [16].…”

Section: Introductionmentioning

confidence: 76%

“…In summary, He bubble damage evolution was studied using in-situ TEM as a function of He + implantation fluence for two strong fusion material candidates (NCW and ultrafine W-TiC alloy). The results have been compared to previously studied SPD nanocrystalline and ultrafine tungsten [15]. Grain boundaries were shown to be decorated with large bubbles, indicating efficient He trapping.…”

Section: Resultsmentioning

confidence: 96%

“…In the current work, the bubble sizes at the grain boundaries in the NCW (~8-10 nm as shown in inset in Figure 2h) were smaller than those in the W-TiC grade (~20-25 nm as shown in the inset in Figure 3h). They were also smaller than the bubbles (~10 nm) at the grain boundaries in the SPD material at the same He + fluence [15]. This represents lower overall bubble damage, which is indicative of a lower He-vacancy complex (with low migration energies) and vacancy transport to the grain boundaries (presumably due to higher levels of recombination).…”

Section: He Bubble Evolution As a Function Of He + Fluencementioning

confidence: 86%

“…The same W-TiC material has previously been demonstrated, under heavy ion irradiation, to have higher irradiation resistance to cavity and loop formation (in the grain matrices) compared to commercial coarse-grained tungsten [14]. In previous work [15], nanocrystalline and ultrafine tungsten (where both elongated nanocrystalline and ultrafine grains coexist-SPD material) was implanted under the same conditions used in the current work. Bubble density in the grain matrices of the W-TiC was five times higher than in the SPD material but the average bubble area was~2.5 times lower in the former.…”

Section: Damage Evolution Comparisonmentioning

confidence: 92%

“…The response of these materials, however, due to low energy He + implantation is still unknown. The testing of severe plastically deformed (SPD) nanocrystalline and ultrafine tungsten, where both elongated ultrafine (<500 nm) and nanocrystalline (<100 nm) grains coexist under low energy He + implantation and high temperatures (1223 K), showed a trend in both damage and He bubble formation as a function of grain size [15]. Grains of less than 60 nm (in elongated grains, size was defined to be the distance across the middle in the narrower direction) demonstrated a high irradiation tolerance to bubble formation and grains of~35 nm were shown to possess minimum damage.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

In-Situ Helium Implantation and TEM Investigation of Radiation Tolerance to Helium Bubble Damage in Equiaxed Nanocrystalline Tungsten and Ultrafine Tungsten-TiC Alloy

et al. 2020

Self Cite

View full text Add to dashboard Cite

The use of ultrafine and nanocrystalline materials is a proposed pathway to mitigate irradiation damage in nuclear fusion components. Here, we examine the radiation tolerance of helium bubble formation in 85 nm (average grain size) nanocrystalline-equiaxed-grained tungsten and an ultrafine tungsten-TiC alloy under extreme low energy helium implantation at 1223 K via in-situ transmission electron microscope (TEM). Helium bubble damage evolution in terms of number density, size, and total volume contribution to grain matrices has been determined as a function of He + implantation fluence. The outputs were compared to previously published results on severe plastically deformed (SPD) tungsten implanted under the same conditions. Large helium bubbles were formed on the grain boundaries and helium bubble damage evolution profiles are shown to differ among the different materials with less overall damage in the nanocrystalline tungsten. Compared to previous works, the results in this work indicate that the nanocrystalline tungsten should possess a fuzz formation threshold more than one order of magnitude higher than coarse-grained tungsten.

show abstract

Section: Introductionmentioning

confidence: 76%

Section: Resultsmentioning

confidence: 96%

Section: He Bubble Evolution As a Function Of He + Fluencementioning

confidence: 86%

Section: Damage Evolution Comparisonmentioning

confidence: 92%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

In-Situ Helium Implantation and TEM Investigation of Radiation Tolerance to Helium Bubble Damage in Equiaxed Nanocrystalline Tungsten and Ultrafine Tungsten-TiC Alloy

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

Irradiation‐Induced Extremes Create Hierarchical Face‐/Body‐Centered‐Cubic Phases in Nanostructured High Entropy Alloys

Jiang

Sun

et al. 2020

Advanced Materials

View full text Add to dashboard Cite

A nanoscale hierarchical dual-phase structure is reported to form in a nanocrystalline NiFeCoCrCu high-entropy-alloy (HEA) film via ion irradiation. Under the extreme energy deposition and consequent thermal energy dissipation induced by energetic particles, a fundamentally new phenomenon is revealed, in which the original single-phase face-centered-cubic (FCC) structure partially transforms into alternating nanometer layers of a body-centered-cubic (BCC) structure. The orientation relationship follows the Nishiyama-Wasserman relationship, that is, (011) BCC || (111) FCC and [100] BCC || [ 110] FCC. Simulation results indicate that Cr, as a BCC stabilizing element, exhibits a tendency to segregate to the stacking faults (SFs). Furthermore, the high densities of SFs and twin boundaries in each nanocrystalline grain serve to accelerate the nucleation and growth of the BCC phase during irradiation. By adjusting the irradiation parameters, desired thicknesses of the FCC and BCC phases in the laminates can be achieved. This work demonstrates the controlled formation of an attractive dual-phase nanolaminate structure under ion irradiation and provides a strategy for designing new derivate structures of HEAs.

show abstract

Prototypic Lightweight Alloy Design for Stellar‐Radiation Environments

et al. 2020

Self Cite

View full text Add to dashboard Cite

The existing literature data shows that conventional aluminium alloys may not be suitable for use in stellar-radiation environments as their hardening phases are prone to dissolve upon exposure to energetic irradiation, resulting in alloy softening which may reduce the lifetime of such materials impairing future human-based space missions. The innovative methodology of crossover alloying is herein used to synthesize an aluminium alloy with a radiation resistant hardening phase. This alloy-a crossover of 5xxx and 7xxx series Al-alloys-is subjected to extreme heavy ion irradiations in situ within a TEM up to a dose of 1 dpa and major experimental observations are made: the Mg 32 (Zn,Al) 49 hardening precipitates (denoted as T-phase) for this alloy system surprisingly survive the extreme irradiation conditions, no cavities are found to nucleate and displacement damage is observed to develop in the form of black-spots. This discovery indicates that a high phase fraction of hardening precipitates is a crucial parameter for achieving superior radiation tolerance. Based on such observations, this current work sets new guidelines for the design of metallic alloys for space exploration.

show abstract

Grain size threshold for enhanced irradiation resistance in nanocrystalline and ultrafine tungsten

Cited by 99 publications

References 33 publications

In-Situ Helium Implantation and TEM Investigation of Radiation Tolerance to Helium Bubble Damage in Equiaxed Nanocrystalline Tungsten and Ultrafine Tungsten-TiC Alloy

In-Situ Helium Implantation and TEM Investigation of Radiation Tolerance to Helium Bubble Damage in Equiaxed Nanocrystalline Tungsten and Ultrafine Tungsten-TiC Alloy

Irradiation‐Induced Extremes Create Hierarchical Face‐/Body‐Centered‐Cubic Phases in Nanostructured High Entropy Alloys

Prototypic Lightweight Alloy Design for Stellar‐Radiation Environments

Contact Info

Product

Resources

About