Fatigue is the most pervasive failure mode that affects nearly all industrial sectors - including energy industries involving power plants, anemo-electric and tidal stream generators; transport vehicles and aircraft; national infrastructure such railway and bridges; military equipment from a blade in an engine to a whole ship; medical devices and human body implants. The economic cost of fracture has been enormous, approaching 4% of GDP, whereas 50-90% of all these mechanical failures are due to fatigue. Most fatigue failures are unexpected, and can lead to catastrophic consequences. In safety-critical sectors such as the aero-space and nuclear industries, there are ever increasing demands for better understanding of fatigue with respect to the microstructure of metallic components and the demanding environments that they are placed in. The ultra-small, ultra fast fatigue testing techniques I have created are able to make a breakthrough by addressing the classic needle in haystack problem in fatigue crack initiation (FCI) and short crack growth (SCG). Fatigue at these early stages is localized within a few hundred micro-meters. However, they account for more than 50% life in low cycle fatigue (LCF) and approximately 90% in the high cycle fatigue (HCF) regime, and contribute to the largest portion of scatter. My micro- and meso- cantilever techniques are capable of isolating FCI and SCG in selected microstructure features, allowing for the systematic exploration of slip evolution, slip band decohesion and short crack propagation in the context of an exquisitely well characterised volume of material. The ultra-fast testing rate up to 20 kHz means robust exploration can be achieved to 10^9 cycles and beyond, in hours in contrast to months or years demanded by the conventional method. This proposal, through further development of state-of-the-art extremely small and fast fatigue testing techniques, looks to radically change the technical scope of fatigue analysis by allowing environmental effects to be systematically explored at the levels of FCI and SCG and across the HCF and LCF regimes. In-situ ultrasonic fatigue testing rig will be installed in an advanced scanning electron microscope, enabling in-situ observation of the progression of HCF FCI and SCG at the resolution of ~ 1 nm. I will apply these cutting edge techniques to underpinning major fatigue issues in Ti and Ni alloys of technologically importance to the aero-engine industry and proton accelerators, specifically: (i) To achieve a breakthrough in mechanistic understanding of HCF FCI and SCG in titanium alloys with respect to the environments and deliver essential HCF FCI and SCG properties; (ii) To make groundbreaking study of fatigue in Alpha Case and dwelling fatigue in titanium alloys, which are major issues in aero-engine industry; (iii) To determine the effect of the heavy irradiation on HCF performance of Ti-alloys that will be used in the next generation proton accelerators; (iv) To achieve comprehensively understanding of the environmental effect on fatigue in single-crystal nickel superalloys that have the heterogeneous distribution of gamma' phase and element segregation; (v) To determine the HCF and LCF performance of the multi-functional coatings on the surface of a nickel turbo blade in the context of atmosphere, temperature and pre-corrosion treatment. A Ultrasonic Fatigue Testing Centre will be established to satisfy the frequent HCF assessment requests from the industry. The new functions developed on the ultrasonic fatigue testing rig in this project will be transferred to the national lab at Culham to update the bespoke rig in a 'hot cell', for study of active materials in support of fission and fusion innovation.

Fatigue is the most pervasive failure mode that affects nearly all industrial sectors - including energy industries involving power plants, anemo-electric and tidal stream generators; transport vehicles and aircraft; national infrastructure such railway and bridges; military equipment from a blade in an engine to a whole ship; medical devices and human body implants. The economic cost of fracture has been enormous, approaching 4% of GDP, whereas 50-90% of all these mechanical failures are due to fatigue. Most fatigue failures are unexpected, and can lead to catastrophic consequences. In safety-critical sectors such as the aero-space and nuclear industries, there are ever increasing demands for better understanding of fatigue with respect to the microstructure of metallic components and the demanding environments that they are placed in. The ultra-small, ultra fast fatigue testing techniques I have created are able to make a breakthrough by addressing the classic needle in haystack problem in fatigue crack initiation (FCI) and short crack growth (SCG). Fatigue at these early stages is localized within a few hundred micro-meters. However, they account for more than 50% life in low cycle fatigue (LCF) and approximately 90% in the high cycle fatigue (HCF) regime, and contribute to the largest portion of scatter. My micro- and meso- cantilever techniques are capable of isolating FCI and SCG in selected microstructure features, allowing for the systematic exploration of slip evolution, slip band decohesion and short crack propagation in the context of an exquisitely well characterised volume of material. The ultra-fast testing rate up to 20 kHz means robust exploration can be achieved to 10^9 cycles and beyond, in hours in contrast to months or years demanded by the conventional method. This proposal, through further development of state-of-the-art extremely small and fast fatigue testing techniques, looks to radically change the technical scope of fatigue analysis by allowing environmental effects to be systematically explored at the levels of FCI and SCG and across the HCF and LCF regimes. In-situ ultrasonic fatigue testing rig will be installed in an advanced scanning electron microscope, enabling in-situ observation of the progression of HCF FCI and SCG at the resolution of ~ 1 nm. I will apply these cutting edge techniques to underpinning major fatigue issues in Ti and Ni alloys of technologically importance to the aero-engine industry and proton accelerators, specifically: (i) To achieve a breakthrough in mechanistic understanding of HCF FCI and SCG in titanium alloys with respect to the environments and deliver essential HCF FCI and SCG properties; (ii) To make groundbreaking study of fatigue in Alpha Case and dwelling fatigue in titanium alloys, which are major issues in aero-engine industry; (iii) To determine the effect of the heavy irradiation on HCF performance of Ti-alloys that will be used in the next generation proton accelerators; (iv) To achieve comprehensively understanding of the environmental effect on fatigue in single-crystal nickel superalloys that have the heterogeneous distribution of gamma' phase and element segregation; (v) To determine the HCF and LCF performance of the multi-functional coatings on the surface of a nickel turbo blade in the context of atmosphere, temperature and pre-corrosion treatment. A Ultrasonic Fatigue Testing Centre will be established to satisfy the frequent HCF assessment requests from the industry. The new functions developed on the ultrasonic fatigue testing rig in this project will be transferred to the national lab at Culham to update the bespoke rig in a 'hot cell', for study of active materials in support of fission and fusion innovation.

The aim of this proposal is to develop novel high performance, nanocomposite feed materials for Additive Manufacturing (AM). The field of AM, also known also as 3D Printing, has expanded significantly over the last couple of decades across virtually all-industrial sectors due a number of key advantages that traditional manufacturing just cannot offer. These include mass customisation, geometrical complexity, tool-less manufacture and sustainable manufacturing. Among the companies using AM are GE (medical devices, and home appliance parts), Lockheed Martin and Boeing (aerospace and defense), Invisalign (dental devices) and LUXeXcel (lenses for light-emitting diodes, or LEDs). The worldwide revenue from 3D printing is expected to grow from $3.07 billion in 2013 to $12.8 billion by 2018, and exceed $21 billion by 2020, and has a potential of generating an economic impact of $230 billion to $550 billion per year by 2025. While the forecast for AM products is huge this will only be achieved if we can actually manufacture parts with the desired properties. The majority of polymeric AM research is however focused on low glass transition temperature (Tg) polymers such as Polyamide 11, 12 , Polycarbonate and Poly Lactic acid (PLA), due to their good processing characteristics (rheological, thermal and crystallization). For advanced, high value applications in aerospace, telecommunication and defense where harsh environmental conditions often exist (and in some key biomedical application) these low Tg polymers for AM are not acceptable so there is a real need to develop materials for these applications. Whilst a sufficiently high Tg polymer could offer the required high performance, nanocomposites with increased functionalities and potential combinations of properties such as high stiffness, strength, wear and specific thermal, electrical and microwave response can really transform the performance of AM components. The ability to manipulate other properties, such as rheological and thermal performance, by the addition of nanoparticles offers further potential advantages in terms of processing characteristics. This proposal will examine the potential of inorganic fullerene-like (IF) tungsten disulfide (WS2) or IF-WS2 as nanofillers for high value, PAEK (Poly Aryl Ether Ketone) based products made via the AM processes of Selective Laser Sintering (SLS) and Fused Deposition Modelling (FDM). The incorporation of IF particles has been shown to be efficient for improving thermal, mechanical and tribological properties of various thermoplastic polymers, such as polypropylene, nylon-6, poly(phenylene sulfide), poly(ether ether ketone). These nanocomposites were fabricated by simple melt-processing routes without the need for modifiers or surfactants . IF-WS2 have been proven to exhibit extremely high tribological performance in composites to reduce wear and coefficient of friction .These characteristics will also have important processability benefits for AM processes as will their dispersion characteristics which are superior to 1D and 2D nanoparticles. They are also the best shock absorbing cage structures known to mankind. Importantly, they are non-toxic, and thermally stable. We will examine the two main AM processes for producing parts with engineering properties, Selective Laser Sintering (SLS) in which a laser is used to melt and sinter powdered polymer into the final part and Fused Deposition Modelling (FDM) in which a polymer filament is melted in a heated nozzle and deposited in the required pattern to form the part.

The machines, products and devices all around us are full of moving parts; from the tiny read/write head in a hard drive, the prosthetic hip joint, the high speed train rail/wheel interface, the most powerful jet engine, to the giant gearboxes in wind turbines. It is the interacting surfaces in these moving parts where friction occurs and energy is lost. Lubrication is required to control friction and minimise the wear that causes premature failure. Selection of suitable rubbing materials and surface treatments helps to make parts last longer. Tribology is the science that encompasses the study of friction, wear, lubrication and surface engineering. It is a true underpinning technology behind developments in all industry sectors. This proposal is for a Centre for Doctoral Training in Integrated Tribology (iT-CDT) to act as a training school and centre for research excellence in tribology. We have established a number of industrial partners who are prepared to make significant cash commitment to the Centre. They will benefit from a supply of highly trained PhD graduates, research focussed on their industry needs, as well as access to a pool of research on generic pre-competitive themes. The two universities are fully supportive of the bid and are providing studentships, staff time, and facilities. The total gearing proposed is £3.75M (45%) from EPSRC, £2.2M from industry (26%), and £2.4M (29%) from the universities. Integrated Tribology Integrated across disciplines - the nature of tribology is such that a multi-disciplinary approach is essential: physics of surfaces, chemistry of lubricants, material and surface treatment technologies, and engineering design. The iT-CDT plans to recruit PhD students and undertake PhD projects that span the disciplines of physics, chemistry, materials science and mechanical engineering. Integrated across industrial sectors - tribology is an underpinning technology in all industry sectors. Many industries face the same generic problems (e.g. operating with thinning films, minimising and/or control of friction, fuel efficiency, reducing maintenance, extreme environments). The iT-CDT plans to integrate across sectors, sharing research expertise and common themes. Integrated over the product life cycle - tribology is involved at all stages of a product lifecycle - from design, manufacture, maintenance, repair, through to disposal. The iT-CDT plans to have projects that span these stages of the lifecycle and to train students in the appreciation of the lifecycle and its sustainability. Integrated across length scales - when surfaces rub together, atomic forces at the interface are responsible for friction and adhesion. The molecular structure of the lubricant and its chemical formulation provide protection. Interaction at this nano-scale governs performance at the macro-scale. The iT-CDT plans to integrate across length scales, combining analysis and methods from nano- to macro- in each project. Integrated across technology readiness level - The iT-CDT plans to give students experience of the different types of research. The Centre's structure of mini-projects, research, and a final impact project will give scope for fundamental pre-competitive research, consultancy type problem solving, and application of research in an industrial environment, respectively.