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| Reference Number | UKRI663 | |
| Title | Explaining ductility in body-centred cubic metals through advanced atomic-scale characterisation | |
| Status | Started | |
| Energy Categories | Nuclear Fission and Fusion (Nuclear Fusion) 100%; | |
| Research Types | Basic and strategic applied research 100% | |
| Science and Technology Fields | PHYSICAL SCIENCES AND MATHEMATICS (Physics) 30%; PHYSICAL SCIENCES AND MATHEMATICS (Metallurgy and Materials) 70%; |
|
| UKERC Cross Cutting Characterisation | Not Cross-cutting 100% | |
| Principal Investigator |
Peter Nellist University of Oxford |
|
| Award Type | Standard | |
| Funding Source | EPSRC | |
| Start Date | 01 February 2025 | |
| End Date | 01 February 2028 | |
| Duration | 36 months | |
| Total Grant Value | £314,313 | |
| Industrial Sectors | Unknown | |
| Region | South East | |
| Programme | ISPF Japan Advanced Materials | |
| Investigators | Principal Investigator | Peter Nellist , University of Oxford |
| Other Investigator | David Armstrong , University of Oxford Laura Clark , University of York |
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| Web Site | ||
| Objectives | ||
| Abstract | Fusion reactors have the promise to provide high quantities of power with zero carbon and greenhouse gas emission during generation. In addition to major, international initiatives such as ITER, recent years have seen a proliferation of small and mid-size enterprises presenting innovative approaches to fusion generation. Unlocking the capabilities of fusion power can form a key component of addressing the UN’s Sustainable Development Goal Number 7 “Ensure access to affordable, reliable, sustainable and modern energy for all” and Goal Number 9 “Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation”. The research proposed here seeks to address a question of key importance in developing fusion reactors: What controls plasticity in refractory metals? This understanding will unlock the development of rationally designed alloys that can form key components in a fusion reactor? A key component of a tokamak is the divertor, which is located near the base of the tokamak and extracts heat and ash produced by the fusion reaction, minimizes plasma contamination, and protects the surrounding walls from thermal and neutronic loads. As such the diverter must withstand extremely high temperatures of over 1000 C at steady state, power densities of ~20MW/m2 and substantial neutron irradiation while maintaining its shape and structural integrity. The materials that can withstand such conditions are based on refractory metals, with tungsten being the preferred candidate due to its low activation and excellent sputtering resistance. Most refractory metals, including tungsten, are brittle at low temperatures but can become more ductile at higher temperatures. The temperature associated with this activation is known as the brittle-ductile transition temperature (BDTT) which can be above room temperature and make such materials unusable as a structural component. Alloying can improve the ductility of refractory metals at low temperatures, but there is little rational understanding of why this occurs. The proposed work brings together capabilities at two UK universities (Oxford and York) and one Japanese (University of Tokyo) to finally unlock a rational explanation of refractory metal ductility by directly imaging dislocation core structures. The key new technology that has unlocked the ability to image the screw dislocation is a combination of aberration correctors in electron microscopy allowing a very high semi-angle of convergence in the probe forming optics combined with the emerging technique of 4D-scanning transmission electron microscopy (4D-STEM). The depth of field of an optical system varies inversely proportionately with the square of the numerical aperture, and so the high convergence angles allowed by the latest generation of aberration correctors leads to a very low depth of focus at nanometre scale. This reduced depth of field can be used to focus on features at specific depths in a sample – an approach known in light optics as optical sectioning. Samples produced and with initial characterisation at Oxford will then be examined at high resolution using unique instrumentation at Tokyo guided by simulations and data processing algorithms developed in work led by York. The aim is to develop a rational understanding of tungsten plasticity to guide the development of alloys to enable the formation of a key component in fusion energy | |
| Data | No related datasets |
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| Projects | No related projects |
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| Publications | No related publications |
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| Added to Database | 29/10/25 | |
