Materials expertise underpins a lot of the support we offer Industrial Members and central to this are the many materials testing projects we have undertaken over our history. Our testing services have supported all industry sectors, from aerospace through to oil and gas, delivering new insights into materials behaviour and capabilities.
Our technical excellence covers a broad range of areas, including coatings and surface corrosion, high pressure CO2 testing - including for carbon capture and storage (CCS) – fatigue testing, fracture mechanics, hydrogen testing, metallurgy and materials characterisation, mechanical and destructive testing, permeation testing, polymer testing, full-scale testing – including full-scale four-point rotating bend testing – residual stress measurement, resonance fatigue testing, sour testing, high temperature testing, and testing in aggressive environments.
TWI projects are conducted on behalf of individual organisations, alongside others as collaborative industry projects, as joint industry projects for the benefit of a specific group of interested parties, or as a wider core research project for the benefit of industry.
Because our work is conducted impartially and independently, we are able to deliver the best results for our Members, while our expertise has also led to a number of innovations as well as being called to provide input to industry standards.
This includes being influential in areas such as hydrogen induced stress cracking of steels…
- Improving Materials Qualification and Design against HISC of Duplex and Super Duplex Stainless Steels
The failure of subsea structures using duplex and superduplex stainless steel due to hydrogen induced stress cracking (HISC) led us to create a 2009 joint industry project to quantify the resistance of such materials to HISC. The data from this project was incorporated into DNV Recommended Practice RP-F112 for the ‘Design of duplex stainless steel subsea equipment exposed to cathodic protection.’
Hydrogen-induced cracking has been a concern for the marine industry for decades, with TWI experts being leading pioneers in understanding the causes and finding solutions. This work has continued with advancements in materials and technologies over the ensuing decades…
- Materials Onboard: Steel Advancements and Integrated Composites
The European Commission-funded MOSAIC project investigated two novel ideas for ship structures; firstly, the introduction of high strength low alloyed steels (HSLA) for specific structural details in order to deal with the issue of crack initiation and propagation in critical areas of ships and, secondly, the replacement of specific structural parts of ships with composite materials.
Corrosion is another common issue faced by subsea and offshore structures, however it is not just in marine environments that corrosion can occur, as shown by our work to help advance geothermal as a reliable, ‘always on,’ renewable energy resource…
- Geo-Coat
The collaborative Geo-Coat project was created to develop specialised corrosion- and erosion-resistant coatings based on selected high entropy alloys (HEAs) and ceramic / metal mixtures (Cermets). These coatings, applied through thermal powder coating techniques (primarily high velocity forms of HVOF / Laser cladding), were specially developed to provide the required bond strength, hardness and density for challenging geothermal applications. These materials needed to meet requirements for resistance to corrosion and erosion to reduce the overall through life costs. This project sought to not only to increase production efficiencies and component longevity, but also to reduce downtime through failures/and or treatments, reduce energy consumption, and deliver positive environmental impacts.
- Geo-Drill
Also focussed on the geothermal sector, the collaborative Geo-Drill project aligned several areas of expertise, including sensor and monitoring technologies and graphene-based materials and coatings to deliver ‘holistic’ drilling technologies with the potential to dramatically reduce the cost of drilling to large depths (5km or more) and at high temperatures (250ºC or more).
Coating materials for parts in aggressive environments were also the focus of the FORGE project, which was investigating their use in energy-intensive industries…
- FORGE
Increased production efficiency and component lifespan in aggressive environments requires materials innovation. This EU-funded, collaborative project aimed to develop cost-effective, protective coatings with the necessary chemical stability, hardness and gas barrier properties to make them suitable for use in a range of challenging applications. Compositionally complex materials (CCMs) were chosen to meet the needs of industry to improve the tolerance capabilities of base structural materials against damage mechanisms such as erosion, corrosion, surface oxidation and hydrogen embrittlement. Materials testing, machine learning models and expert thermodynamic calculations were aligned with high-throughput experiments during the project, which reduced costs and improved processes such as waste heat recovery, carbon capture, alternative process chemistries and high-energy processes, increasing output and efficiency, while reducing greenhouse gas emissions for industries such as steel, aluminium, cement and ceramics.
While these projects worked to solve specific industry problems, our technical excellence in materials and testing is also used to achieve wider industry goals, such as for materials suitable for CO2 carbon capture and storage and oil and gas service…
- Materials Technology Gap Analysis for Handling CO2 in Carbon Capture and Storage (CCS), and Oil and Gas Service
This 2010 core research project was focused on carbon dioxide capture and storage (CCS), a carbon sequestration method, which is recognised as a means of utilising carbon-based fuels whilst minimising the release of CO2 into the atmosphere. Primarily, this involves capturing the CO2 arising from industrial and energy-related sources, separating it from some other gases, if needed, compressing it, and then transporting and injecting it into a storage site such as depleted oil and gas wells or saline aquifers to ensure long-term isolation from the atmosphere. Although the CCS concept is based on a combination of known technologies, large scale adoption and integration of individual existing technologies poses challenges. These technological challenges range from corrosion and structural integrity of materials to safety inspection during operation. Understanding these issues, mitigating if necessary, and filling the technology gaps in full scale implementation of CCS is important for its wider adoption as a CO2 emission reduction tool, and this project sought to identify materials technology gaps in the full scale implementation of CCS.
- Combined Permeation of Pressurised CO2 with Impurities through Thermoplastics
Continuing our work with CCS, this 2024 joint industry project was created to assess the barrier performance of thermoplastic polymers that are used as a barrier layer against impurities in carbon dioxide (CO2) feedstock such as water vapour, ammonia, nitrous oxide, hydrogen and hydrogen sulphide. Using our permeation facility, supported by gas chromatographs, to measure the rate of transport through thermoplastics of CO2 with water vapour and trace amounts of one of hydrogen sulphide, ammonia, nitrous oxide or hydrogen over several months. The aim being to establish the barrier performance of thermoplastic materials to CO2 with associated impurities as well as if any transport of these impurity species causes ageing in the thermoplastic matrix. This work provided guidance as to which generic CO2 composition with impurities are relevant to assess the barrier properties and ageing of thermoplastics.
Our materials expertise also extends to the use of cold spray to repair components that have suffered relatively minor damage resulting from corrosion, wear or foreign object damage…
- Improving and Industrialising Cold Spray Repair
This cold spray repair joint industry project was created to deliver cost savings by eliminating the need to install new parts by instead effecting a strategy of cold spray repairs. As well as reducing the energy use and CO2 emissions associated with replacing parts, cold spray avoids the heat input and associated alterations to a material’s underlying microstructure that comes with current fusion/weld-based repairs of metallic components. This project developed new approaches to cold spray, improving deposit performance and allowing a broader range of materials to be sprayed. In addition, our experts generated independent data on the performance of cold spray deposits to aid users in the development of safety cases and future certification, as well as creating guidelines to support the implementation of cold spray, allowing the project sponsors to better understand potential benefits, limitations and costs.
- Structural Integrity of Additive Manufactured Materials
Additive manufacturing (AM) has gained increased interest in recent years for its potential to produce customised components with complex geometries. However, in spite of this advantage, the material behaviour produced by AM is not fully understood yet, mainly due to the different manufacturing processes that the material goes through compared to conventional processes, such as complex thermal history, layer-wise manufacturing, and a large number of process parameters. Changing these can affect the final products in terms of their microstructure and accordingly mechanical performance. This project was created to help to understand AM material behaviour before using AM parts in safety-critical applications. It has been observed that many failures in safety-critical components occur due to fatigue and/or fracture, therefore, it was deemed important to assess the AM material performance under both these modes of failure.