Energy and the Physical Sciences: Novel multi-seeded bulk superconductors for sustainable engineering applications

The ability to generate strong and stable magnetic fields is a critical enabling technology for a broad range of sustainable engineering applications. Almost invariably, more compact field sources and higher magnetic field densities lead directly to more efficient and cost effective devices. One example of this can be found in the widespread applications of small, high power DC electric motors, which have proliferated since the development of the cheap high energy density family of NdFeB materials in the 1980s. Wire-wound superconducting magnets, on the other hand, may offer the potential to generate large magnetic fields, but they are extremely expensive and are difficult to manufacture. A cheaper, simpler and more robust option is the use of magnetised bulk superconductors. The (RE)BCO (where RE = rare earth element such as Y, Nd, Sm, Gd, etc.) family of bulk, melt processed high temperature superconductors (HTS), in particular, is the subject of extensive world-wide developmental research. Bulk HTS materials offer considerable potential to both improve the performance of existing devices that incorporate permanent magnets and to develop new, high field and sustainable energy storage applications, in particular. Indeed, these materials represent a direct link between the physical sciences and the development of sustainable applications in the energy needs sector that will be fundamental to growth of the UK economy in the short to medium term.

A number of important scientific and technical challenges to the incorporation of (RE)BCO bulk superconducting materials into practical engineering applications remain. These include improving process efficiency, sample properties, yield, reducing the cost of raw materials, recycling, processing larger samples with conformal geometries, development of a practical magnetisation process and the development of bespoke cryogenic systems for specific applications.

The main objective of this proposal is to address and overcome the critical aspects of these challenges to gain a fundamental understanding of the single grain growth process. This will enable the cost-effective processing of (RE)BCO materials with conformal geometries that will be fundamental to their application in a range of sustainable engineering devices within the energy sector and healthcare industry. Specific emphasis of the project will be placed on the development of an effective recycling process to enable a new secondary bulk sample source for low to medium field applications, the development of a novel multi-seeding technique for fabricating large samples of conformal geometry and the development of a novel fabrication process based on a graded composition to produce bulk samples with homogeneous superconducting properties throughout the bulk microstructure.

The impact of this project will be particularly significant for the Cambridge Group and the collaborators, building on an outstanding research and collaboration track record. The project will also benefit both industry and academia worldwide: 1. Engineering industries involved in the manufacture of magnetic bearings, flywheel energy storage systems, high field permanent magnet devices and magnetic separators; 2. Companies manufacturing permanent magnet MRI/NMR systems; 3. High efficiency, compact motors and generators. Researchers working on magnetic and transport properties, solidification and phase kinetics of (RE)BCO materials will also benefit directly from the results of the project. Samples will be supplied to the relevant UK academic institutions and schools free of charge, as required.

The main mechanism for impact and exploitation is via the established collaboration with Boeing Company, which has a number of large, active (propriety) projects with potential users of bulk material in energy storage flywheel systems and other applications such as non-destructive testing. This is a ready-made market, and offers a unique opportunity for the UK to make a major impact on HTS technology on an international scale. Unfortunately the details of these projects are proprietary, although they represent a combined potential market of tens of millions of dollars in the medium to long term. State of the art bulk material developed as part of this project would be retro-fitted into these existing devices (approximately 50 samples in each energy storage flywheel device) to yield a direct route to commercial exploitation. Other emerging applications relevant to developing sustainable engineering technologies include high efficiency, light and compact motors and generators, testing applications requiring a large magnetic field, stable magnetic bearings, fault current limiters and magnetic separators. Boeing has potential interest in these devices, and is well-placed to supply the global market. Cambridge and Boeing have an existing, formal IPR agreement in place, including joint patent interests, and the partnership is well-positioned to fully exploit emerging bulk superconductor technology. The outputs with potential technical and commercial impact will be identified by comparing the properties, manufacturability and cost of state of the art bulk samples with the requirements of global industry, as defined mainly by the Boeing Company. This will provide bench-mark data by which to evaluate the output of the project and enable comparison with competing technology (where it exists). Key properties are the magnitude of trapped field at 77 and 50 K, mechanical strength and production cost, which will be monitored by Boeing as part of the project. In-situ performance of bulk samples in the Boeing energy storage flywheel will provide further technical output to quantify the capability of the bulk materials in an applications-specific environment.

The SRA appointed to the project will undertake the impact activities in close collaboration with the PI. Prof. Cardwell has extensive experience of the generation and protection of IPR, and is well placed to oversee and manage this project. Cambridge Enterprise (a University body established to advise and support the commercial exploitation of emerging technology) will be involved closely with the transfer of manufacturing technology outside the University. Cambridge Enterprise employs specialists in IPR, market research and contract law at no direct cost to the project, and will play a key role in the exploitation of the commercial potential of the material developed during this research.