EPSRC Reference: |
EP/D50029X/1 |
Title: |
Platform: Fracture, Fatigue and Durability of Advanced Alloys and Composites for High Performance Applications |
Principal Investigator: |
Bowen, Professor P |
Other Investigators: |
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Researcher Co-Investigators: |
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Project Partners: |
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Department: |
Metallurgy and Materials |
Organisation: |
University of Birmingham |
Scheme: |
Platform Grants (Pre-FEC) |
Starts: |
01 September 2005 |
Ends: |
28 February 2011 |
Value (£): |
431,488
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EPSRC Research Topic Classifications: |
Materials Characterisation |
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EPSRC Industrial Sector Classifications: |
Aerospace, Defence and Marine |
Manufacturing |
Transport Systems and Vehicles |
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Related Grants: |
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Panel History: |
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Summary on Grant Application Form |
Failure of metal structures such as aircraft or nuclear pressure vessels can have catastrophic consequences, putting lives in danger or having a major economic impact. It is therefore important to predict how long structures can operate safely.Two main causes of failure of metal structures are the stresses on, the components, which may be static or oscillating, and corrosive attack by the environment. The combined effect of stress and corrosion can lead to environmentally-assisted cracking , which can be much faster than cracking caused by either stress or corrosion acting alone. Failures sometimes take place in extreme environments at high temperatures or in highly corrosive environments. Failure of a metal structure usually involves the formation of cracks in load-bearing regions, or the penetration of the structure by corrosion. It is possible to measure the rate of cracking and corrosion in the laboratory on small specimens over a period of hours, days or weeks, but real structures fail over periods of years. If we want to use laboratory failure rates to predict service life, it is essential to understand the mechanisms of the failure processes to ensure that our longterm predictions on large structures are valid. In parallel with this, it is important to carry out rigorous statistical analysis to assess the limits, errors and risks in such predictions.As living organisms are made up of cells, which have a fine structure of organelles inside them, so metals are made up of individual grains, with varying distributions of precipitates and impurity elements. The failure of metals is determined by this microstructure . Our research focuses on determining how cracks and regions of local corrosion interact with different microstructural features. To do this, we use experimental approaches that allow us to probe processes on the micron and sub-micron scale. For example, we have a device for stressing metals inside an electron microscope for observing the interaction of submicron cracks with microstructural features, and a microelectrochemical cell for measuring the local rates of corrosion at the tip of a glass pipette that is the width of a human hair.A broad range of techniques can be used to understand failure mechanisms: in addition to many standard testing methods, we detect the progress of cracks by picking up tiny electrical or acoustic signals, and the evolution of corrosion through video microscopy of the evolution of damage. We are starting to use X-ray microtomography to detect the penetration of corrosion and cracks into solid metal; this is an approach equivalent to MRI scanning of the human body, which can be carried out on small metal samples at the submicron scale at X-ray synchrotron facilities.Our work covers a range of industries, with a focus on transport (airframe structures, aeroengines, ships, submarines and cars) and energy generation (gas turbines, nuclear pressure vessels). We investigate both the safe life of existing components, and also the introduction of new technologies, such as high strength fibre-reinforced titanium and new kinds of welds that will, for example, allow the replacement of rivets in aircraft.The ability to predict a safe operating life of metal structures is critical to a number of UK industries, and yet there are relatively few groups who have the infrastructure and expertise to do this under a broad range of sometimes extreme conditions where both cracking and corrosion can cause problems. The proposed platform grant will help us to maintain our level of expertise by carrying out studies to extend the range of both experimental and statistical methods that we can use to investigate failure mechanisms. We will also develop collaborative interactions with key groups around the world to ensure that we are working at the forefront of the field, and increase the visibility of UK research on the international stage.
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Key Findings |
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Potential use in non-academic contexts |
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Impacts |
Description |
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Summary |
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Date Materialised |
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Sectors submitted by the Researcher |
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Project URL: |
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Further Information: |
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Organisation Website: |
http://www.bham.ac.uk |