Design of next-generation automotive corrosion protective coatings by improving inhibitor transport properties
Lead Research Organisation:
Swansea University
Department Name: College of Engineering
Abstract
The protective coatings industry is currently facing a multi-billion pound challenge to find successful materials substitution for toxic hexavalent chromium-based anti-corrosion agents, typically incorporated as sparingly soluble salt pigments within an organic coating. Cr(VI) use has been assigned a "sunset" date of 2019 by the European union, after which it will be banned. As such there is an urgent need to identify new, environmentally corrosion inhibitive technologies showing equivalent, if not better protective capability. This project provides an excellent opportunity to work with a world leading company involved in the automotive coatings market, namely BASF Automotive, to develop new Cr(vi)-free corrosion inhibitive technologies which will deliver corrosion protection more effectively. The current state of the art, involving phosphate based technology, remains limited since release of active corrosion inhibitive agents into coating defect regions is not well controlled. As a result, there is now significant interest in exploiting the properties of intelligent-release pigments, in which corrosion inhibitive species are stored and only released "on-demand" in the presence of aggressive corrosion-inducing agents. Furthermore, there is also a need to improve the transport of inhibitor species from the bulk of the coating to the areas where they are required (e.g. defects where the underlying metal is exposed). Currently, only a finite quantity of inhibitor originating from the coating in the immediate vicinity of the defect may available to protect exposed metal. By introducing long-range percolation networks within the coating, it is hoped that enhanced transport of inhibitor to defect regions can produce significantly more effective corrosion inhibition at the exposed metal.
Project aims:
1. To investigate the efficiency of inhibition at penetrative coating defects using current state of the art phosphate based pigments and novel smart-release ion-exchange pigments containing various corrosion inhibitive species.
2. To carry out detailed studies with varying in-coating loadings of the above mentioned pigments to evaluate the effect on speed of inhibitor release.
3. To assess novel inhibitor delivery systems such as nanotube reservoirs, ion exchange resins and minerals, conducting polymer networks as a means of introducing a long-range percolation pigment network within the protective organic coating.
4. To evaluate how long range transport of inhibitor from an optimised system influences the mechanism of coating failure due to de-adhesion originating from corrosion-driven anodic and/or cathodic disbondment in the vicinity of a penetrative defect.
The main thrust of the work will be to develop next-generation protective coatings for technologically important light alloy surfaces, typically aluminium and possibly magnesium automotive alloy grades, although the best performing technologies may also be applied to the protection of steel. The program of work will exploit world-leading expertise in advanced electrochemical scanning techniques, coupled with high throughput methodologies to quantify corrosion protection efficiency and provide mechanistic understanding of inhibition mechanisms.
The investigation will be carried out using comprehensive in-situ and ex-situ electrochemical characterization by means of scanning Kelvin Probe (SKP), Scanning Vibrating electrode technique (SVET), alongside potentiodynamic and electrochemical impedance spectroscopy methods in the laboratories of the Swansea University corrosion research group. Surface chemical and structural characterization will be carried using a world class suite of instrumentation including X-ray-photoelectron spectroscopy (XPS), glancing angle X-ray diffraction (XRD), and field emission gun scanning electron microscopy (FEG-SEM), available in the Materials Research Centre at the College of Engineering.
Project aims:
1. To investigate the efficiency of inhibition at penetrative coating defects using current state of the art phosphate based pigments and novel smart-release ion-exchange pigments containing various corrosion inhibitive species.
2. To carry out detailed studies with varying in-coating loadings of the above mentioned pigments to evaluate the effect on speed of inhibitor release.
3. To assess novel inhibitor delivery systems such as nanotube reservoirs, ion exchange resins and minerals, conducting polymer networks as a means of introducing a long-range percolation pigment network within the protective organic coating.
4. To evaluate how long range transport of inhibitor from an optimised system influences the mechanism of coating failure due to de-adhesion originating from corrosion-driven anodic and/or cathodic disbondment in the vicinity of a penetrative defect.
The main thrust of the work will be to develop next-generation protective coatings for technologically important light alloy surfaces, typically aluminium and possibly magnesium automotive alloy grades, although the best performing technologies may also be applied to the protection of steel. The program of work will exploit world-leading expertise in advanced electrochemical scanning techniques, coupled with high throughput methodologies to quantify corrosion protection efficiency and provide mechanistic understanding of inhibition mechanisms.
The investigation will be carried out using comprehensive in-situ and ex-situ electrochemical characterization by means of scanning Kelvin Probe (SKP), Scanning Vibrating electrode technique (SVET), alongside potentiodynamic and electrochemical impedance spectroscopy methods in the laboratories of the Swansea University corrosion research group. Surface chemical and structural characterization will be carried using a world class suite of instrumentation including X-ray-photoelectron spectroscopy (XPS), glancing angle X-ray diffraction (XRD), and field emission gun scanning electron microscopy (FEG-SEM), available in the Materials Research Centre at the College of Engineering.
Planned Impact
The COATED2 CDT will support the aims of the EPSRC/TSB SPECIFIC IKC and the EPSRC CIM in Large Area Electronics at Swansea University through the provision of 40 research engineers (REs). The SPECIFIC IKC has ambitious targets to create buildings that are power-stations through the use of functional coatings. The targets include:
- A £1billion UK manufacturing sector creating business opportunities with export potential
- Creation of around 7,000 manufacturing/construction sector jobs
- Generation of up to 1/3 of the UK's renewable energy target
- Reduction in CO2 emissions of up to 6 million tons
The CIM in Large Area Electronics has key aims that are synergistic with the IKC, in particular to address the challenges of low-cost manufacturing of multi-functional LAE systems and to support the scale-up of technologies for functional materials. Both projects have shared technologies and processes and RE support through COATED2 will have significant impact on achieving their aims through:
- The supply of highly trained and enthusiastic REs for a growing new industry base
- Encouraging radical thinking for REs in terms of optimisation and up-scaling of laboratory concepts to an industrial scale
- Achieving greater engagement with new and existing industry and academic partners.
The COATED2 RE cohorts will provide impact in a number of key areas -
Knowledge
- Research projects defined by industry with a real scientific or engineering need at their core ensuring relevant research is embedded within the industrial partner/University.
- Engagement of multiple partners through the CDT/IKC's open innovation arrangements permits sharing of knowledge between otherwise discrete industries
- Each RE will produce 3 publications and attend 1 international conference disseminating knowledge into the academic community.
- RE research will be evidenced in taught modules ensuring that quality of training is enhanced year on year.
- Development of new technologies will create a lead for the UK in up-scaling of complex functional coated products.
- Training modules are accessible to Industrial partners providing knowledge beyond the scope of the core CDT.
Economy
- Future industry leaders will be created from the CDT. 96% of previous REs at Swansea have moved onto industry related careers.
- Innovative new products and processes will catalyse new industries and technology advances in established manufacturers generating wealth.
- 8 Patents have been filed by the IKC since 2011 and REs are critical for the on-going development of IP exploitation.
- SPECIFIC Innovations has been established to develop business models and spin-out companies for the exploitation of IP created through the CDT and IKC attracting inward investment.
- The facilities within SPECIFIC and the CIM coupled with extensive industrial partners bridges the gap between research and wealth creation ensuring that outputs from the CDT are maximised.
Society
- REs will engage in active outreach to promote their research and attract more people into STEM activities.
- There have been over 1000 separate visits to the IKC/CDT raising awareness of the product potential to a range of end users.
- Research activity at the CDT supporting the IKC and the CIM will contribute towards alleviating fuel poverty, reducing CO2 output and providing energy security
- Water purification, bio-inspired coatings and durability research benefits developed and developing nations.
People
- The CDT will produce 40 highly skilled individuals trained to support industry and academia
- Graduates of the scheme moving into employment will grow networks between academia and industrial partners creating new opportunities for the CDT.
- Shared seminars with other institutions will enable REs to gain insights into complementary research and raise awareness of available facilities and resources
- A £1billion UK manufacturing sector creating business opportunities with export potential
- Creation of around 7,000 manufacturing/construction sector jobs
- Generation of up to 1/3 of the UK's renewable energy target
- Reduction in CO2 emissions of up to 6 million tons
The CIM in Large Area Electronics has key aims that are synergistic with the IKC, in particular to address the challenges of low-cost manufacturing of multi-functional LAE systems and to support the scale-up of technologies for functional materials. Both projects have shared technologies and processes and RE support through COATED2 will have significant impact on achieving their aims through:
- The supply of highly trained and enthusiastic REs for a growing new industry base
- Encouraging radical thinking for REs in terms of optimisation and up-scaling of laboratory concepts to an industrial scale
- Achieving greater engagement with new and existing industry and academic partners.
The COATED2 RE cohorts will provide impact in a number of key areas -
Knowledge
- Research projects defined by industry with a real scientific or engineering need at their core ensuring relevant research is embedded within the industrial partner/University.
- Engagement of multiple partners through the CDT/IKC's open innovation arrangements permits sharing of knowledge between otherwise discrete industries
- Each RE will produce 3 publications and attend 1 international conference disseminating knowledge into the academic community.
- RE research will be evidenced in taught modules ensuring that quality of training is enhanced year on year.
- Development of new technologies will create a lead for the UK in up-scaling of complex functional coated products.
- Training modules are accessible to Industrial partners providing knowledge beyond the scope of the core CDT.
Economy
- Future industry leaders will be created from the CDT. 96% of previous REs at Swansea have moved onto industry related careers.
- Innovative new products and processes will catalyse new industries and technology advances in established manufacturers generating wealth.
- 8 Patents have been filed by the IKC since 2011 and REs are critical for the on-going development of IP exploitation.
- SPECIFIC Innovations has been established to develop business models and spin-out companies for the exploitation of IP created through the CDT and IKC attracting inward investment.
- The facilities within SPECIFIC and the CIM coupled with extensive industrial partners bridges the gap between research and wealth creation ensuring that outputs from the CDT are maximised.
Society
- REs will engage in active outreach to promote their research and attract more people into STEM activities.
- There have been over 1000 separate visits to the IKC/CDT raising awareness of the product potential to a range of end users.
- Research activity at the CDT supporting the IKC and the CIM will contribute towards alleviating fuel poverty, reducing CO2 output and providing energy security
- Water purification, bio-inspired coatings and durability research benefits developed and developing nations.
People
- The CDT will produce 40 highly skilled individuals trained to support industry and academia
- Graduates of the scheme moving into employment will grow networks between academia and industrial partners creating new opportunities for the CDT.
- Shared seminars with other institutions will enable REs to gain insights into complementary research and raise awareness of available facilities and resources
People |
ORCID iD |
| Geraint Williams (Primary Supervisor) | |
| Victoria Dickson (Student) |