Robotic Additive Manufacturing for Remote In-situ Repair of Vertical Tungsten Plasma-facing Tiles in Tokamaks PhD

Brief outline of area/discipline the project relates to and its relevance today: Fusion energy has the potential to transform the global energy landscape by offering a low-carbon, sustainable source of energy, with the prospect of abundant fuel and no greenhouse gas emissions during operation. Realising this potential requires breakthroughs in advanced materials, manufacturing and engineering to withstand the extreme conditions inside fusion reactors. In tokamak fusion reactors, tungsten plasma-facing tiles are exposed to intense heat and particle flux, making them susceptible to damage and erosion over time. Repairing these components presents significant technical challenges, creating a need for innovative in-situ repair solutions. Robotic additive manufacturing offers an exciting opportunity to repair damaged components remotely, potentially reducing maintenance complexity, cost and reactor downtime. This project integrates advanced additive manufacturing, thermal–mechanical modelling and intelligent robotic monitoring and control to address key engineering challenges and help accelerate the development of reliable fusion energy technologies. 

This PhD project aims to develop a robotic additive manufacturing approach for the remote, in-situ repair of damaged vertical tungsten plasma-facing tiles in tokamak fusion reactors. The research will investigate and optimise wire-based directed energy deposition processes, including arc, laser and hybrid approaches, to achieve crack-free, geometrically stable tungsten deposition on vertical and inclined surfaces. By combining experimental investigations with thermal–mechanical modelling, the project will explore heat transfer, residual stress development and cracking mechanisms to improve the understanding and reliability of the repair process. The research will also investigate the influences of deposition orientation and robotic flexibility on repair quality, followed by developing a sensor-integrated monitoring and real-time feedback control system to enhance process stability, minimise defects and enable reliable remote repair under challenging conditions.

Cranfield overview and Sponsor Information/Background: Cranfield University is a specialist postgraduate university with a strong focus on science, engineering, technology and innovation, delivering impactful research to address real-world industrial challenges. This PhD project is supported by EPSRC, Cranfield University and the UK Atomic Energy Authority (UKAEA). UKAEA will contribute expertise in robotics and manufacturing processes through the supervision of the student working on the fusion-related research. The collaboration will provide opportunities to access UKAEA’s associated robotics platforms and specialist materials for experimental investigations. The student will also undertake an industrial placement of up to three months at UKAEA, gaining valuable practical experience in advanced robotics, manufacturing technologies and fusion-related engineering. This partnership will strengthen the link between academic research and industrial application, supporting the development of innovative solutions for future fusion energy systems.

Expected impact/results of research project: The research is expected to advance the development of reliable robotic additive manufacturing technologies for the remote, in-situ repair of tungsten plasma-facing tiles in tokamak fusion reactors. The project will deliver optimised wire-based deposition processes, a validated thermal–mechanical model and practical guidelines for achieving stable, crack-free deposition on vertical and inclined tungsten surfaces. The development of sensor-integrated monitoring and control will further enhance process stability, geometric accuracy and repair quality under challenging operating conditions. The outcomes will provide a validated repair methodology and improved understanding of tungsten deposition, supporting future applications in fusion reactor maintenance. By addressing key manufacturing and engineering challenges, the research has the potential to reduce component replacement requirements, maintenance complexity and reactor downtime, contributing to the long-term reliability and commercial viability of fusion energy technologies.

This PhD offers a distinctive opportunity to undertake interdisciplinary research addressing real-world challenges in fusion energy, with a strong emphasis on translating innovative engineering solutions into industrial applications. The collaboration between Cranfield University and UKAEA will provide the student with access to specialist expertise, platforms and materials. Funding is also provided for the student to attend national and international conferences. An industrial placement of up to three months at UKAEA will offer first-hand exposure to a fusion research environment and the opportunity to engage with industry-relevant technologies. The project combines experimental research, advanced modelling and robotic system application, providing an opportunity to contribute to emerging technologies with the potential to support the future deployment of fusion energy.

Throughout the PhD, the student will develop a broad range of technical, analytical and transferable skills that will support their future career. These will include experimental design, advanced manufacturing, thermal–mechanical modelling, data analysis, critical thinking and independent problem-solving. The student will also strengthen their research planning, project management, teamwork, interdisciplinary collaboration, scientific writing and presentation skills through joint academic-industry supervision, research activities and Cranfield’s Doctoral Researchers Core Development Programme. Experience of working in an industry-focused research environment will help develop the ability to communicate technical findings, manage complex engineering challenges and translate research outcomes into practical solutions. These capabilities will prepare the graduate for a wide range of career opportunities in advanced manufacturing, robotics, materials engineering, fusion energy, industrial research and development, and other technology-intensive sectors.