Investigating Corrosion Using a High Speed AFM

Lead Research Organisation: University of Bristol
Department Name: Physics

Abstract

There are significant safety and economic incentives to prevent the failure of structural
components in the nuclear industry[1]. Stainless steels are widely utilised in the nuclear
industry due to their amicable mechanical properties, however, they remain susceptible to
corrosion. Corrosion can be affected by a number of different factors and as such is
considered a highly complex process that is under much ongoing research[1]. Conjoint
corrosion and stressing of a metal or alloy, such as stainless steel, can result in stress
corrosion cracking (SCC)[2]. SCC results in significant degradation of component structural
strength whilst being difficult to identify in early stages, thus, SCC is often undetected prior
to failure[1]. The unpredictable nature of SCC calls for considerable research in the
mechanisms under which SCC and other forms of destructive corrosion occur, in steels and
other engineering alloys[2].
To investigate the processes by which corrosion occurs it is required that the sample is
imaged in controlled environments[3]. The field of atomic force microscopy (AFM) has
allowed for high-resolution imaging of structures and the measuring mechanical properties
at nanometre scales in varying gaseous, liquid and vacuum environments[4]. AFM has a
multitude of applications in materials, surface and biological sciences, and is considered one
of the most versatile and significant tools in nanoscience.
Significant effort to increase the imaging rate in recent years has allowed for dynamic
nanoscale events to be observed directly in real time[3]. The applications for high-speed
AFM (HS-AFM) are still relatively new and unexplored, and advances in HS-AFM
technology are ongoing. HS-AFM is a valuable tool for studying solid-liquid interfaces and
so has the potential for use in corrosion studies as it offers the opportunity to observe
dynamic nanoscale structures within in vivo conditions[3].
Laferrere et al. have previously demonstrated the use of the Bristol contact mode HS-AFM
to image nanoscale corrosion events, with parallel electrochemical control[3]. This work
demonstrated the ability of HS-AFM to image steels clearly in liquid environments and the
potential for new insights into corrosion at nanoscales[3]. The main aims of this PhD are to:
- Investigate the conditions that may lead to corrosion and SCC initiation, and to observe
and measure changes to the sample as corrosion takes place in real time using HS-AFM.
- Demonstrate the capability and potential of HS-AFM for applications in material and
corrosion science.

References:
[1] R. Cottis et al., Shreir's Corrosion. Elsevier Science, 2009.
[2] R. Cottis, National Physical Laboratory, Teddington, 2000. 1
[3] O. Payton et al., Nanotechnology, vol. 23, no. 20, p. 205704, 2012.
[4] H.-S. Liao et al., Rev. of Scientific Instruments, vol. 84, no. 10, p. 103709, 2013.

Publications

10 25 50
publication icon
Alzahrani H (2018) Dynamics of nanointerfaces: general discussion. in Faraday discussions

publication icon
Laferrere A (2017) In situ imaging of corrosion processes in nuclear fuel cladding in Corrosion Engineering, Science and Technology

publication icon
Moore S. (2017) Investigating corrosion using high-speed AFM in EUROCORR 2017 - The Annual Congress of the European Federation of Corrosion, 20th International Corrosion Congress and Process Safety Congress 2017

Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/P510427/1 30/09/2016 31/12/2021
1834852 Studentship EP/P510427/1 30/09/2016 30/03/2021 Stacy Moore
 
Description Stress corrosion cracking (SCC) is a form of localised corrosion that can result in failure of stainless steels. Within my work I have developed a new methodology for the research of SCC by contact mode high-speed atomic force microscopy (HS-AFM). This method has allowed for high-resolution observations to be performed of SCC processes as cracking occurs. This allows for real data input into existing theoretical models.

Furthermore, HS-AFM measurements have been performed on fuel cladding from a nuclear reactor, allowing for comparisons to be made on thermally sensitised analogues. This further bolsters results drawn from proxy samples.
Exploitation Route The developed methodology may be used by other researchers for other metal/solution systems for further SCC experiments. Methods may also be used within industry, such as the nuclear sector or aerospace. In addition, research outcomes may be used to inform new models, as well as safety cases within the nuclear industry.
Sectors Aerospace

Defence and Marine

Construction

Energy

Environment

Transport

 
Description MIT 
Organisation Massachusetts Institute of Technology
Country United States 
Sector Academic/University 
PI Contribution Visit to MIT for collaborative experimental work on stress corrosion cracking samples, ongoing collaboration for the use of high pressure high temperature AFM.
Collaborator Contribution Visit to MIT for collaborative experimental work on stress corrosion cracking samples, application to the University of Bristol's International Strategic Fund.
Impact No formal outcomes currently.
Start Year 2021
 
Description Big Bang Outreach 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Big Bang Festival for Outreach in Nuclear. I helped out on a stall teaching primary school age children about nuclear power, answering the question: Is nuclear green?
Year(s) Of Engagement Activity 2017
 
Description Hanham School Outreach 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact Outreach at Hanham School with the Lego AFM. I gave demonstrations of the Lego AFM to secondary school students.
Year(s) Of Engagement Activity 2018
 
Description Open Day Physics 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Other audiences
Results and Impact University open day. This included talking about the importance of nuclear power and demonstrations with a 3D printer with prospective undergraduate students.
Year(s) Of Engagement Activity 2017,2018
 
Description Soapbox Science 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact Soapbox Science Presenter. A virtual outreach event in which I gave a presentation titled: "A New Way to Study Corrosion.
Year(s) Of Engagement Activity 2021