Oxidation Damage at a Crack Tip and Its Significance in Crack Growth under Fatigue-Oxidation Conditions
Lead Research Organisation:
University of Warwick
Department Name: WMG
Abstract
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People |
ORCID iD |
| Barbara Shollock (Principal Investigator) |
Publications
Efthymiadis P
(2017)
Revealing the mechanical and microstructural performance of multiphase steels during tensile, forming and flanging operations
in Materials Science and Engineering: A
Farukh F
(2016)
Realistic microstructure-based modelling of cyclic deformation and crack growth using crystal plasticity
in Computational Materials Science
Farukh F
(2015)
Fatigue crack growth in a nickel-based superalloy at elevated temperature - experimental studies, viscoplasticity modelling and XFEM predictions
in Mechanics of Advanced Materials and Modern Processes
Ismail F
(2017)
Alloying effects on oxidation mechanisms in polycrystalline Co-Ni base superalloys
in Corrosion Science
Jiang R
(2017)
Effects of oxygen-related damage on dwell-fatigue crack propagation in a P/M Ni-based superalloy: From 2D to 3D assessment
in International Journal of Fatigue
Proprentner, D
(2014)
Fatigue Crack Propagation and the Role of Oxidation Ahead of the Crack Tip in LSHR,
| Description | This project aimed to test and measure oxygen diffusion and oxidation-induced damage at a crack tip in nickel superalloys under industrially relevant conditions, ultimately leading to the provision of a predictive model for crack growth. New methodologies were developed and interesting results were produced through the joint efforts of three institutions and four industrial partners. Firstly, critical results of crack growth behaviour have been generated for polycrystalline (PM LSHR; 725?C) and SX (MD2; 825?C) nickel alloys, in controlled environments, including vacuum and isotopically 18O2 enriched, at a range of dwells at elevated temperature. Secondly, a direct examination of oxy-gen distributions in and around the crack has been delivered, including a quantification of the ex-tent of oxygen-induced damage during fatigue. Study revealed the importance of oxygen diffusion along crack path, controlled by temperature, dwell at maximum load and environment. Static oxidation tests were also carried out to calibrate the damage mechanisms and oxygen diffusion parameters to feed into modelling work. Thirdly, a new computer model has been developed to simulate the fully-coupled interaction between oxygen diffusion and crack-tip deformation. The mod-el was utilised for prediction of oxygen penetration into the crack tip, and also for quantification of the compressive stress field near the crack tip generated by oxygen diffusion or oxidation process which was the first ever effort. Finally, a two-parameter criterion, in terms of mechanical deformation and oxygen penetration, has been proposed to control crack growth. The criterion was combined with XFEM to develop an efficient numerical procedure for crack growth prediction under fatigue-oxidation conditions. The model was able to predict the crack growth behaviour ob-served and measured experimentally. These significant outcomes are anticipated to provide further scientific support for ensuring the structural integrity of high-temperature alloy components in terms of fatigue design and life management of critical alloy components under typical service conditions. |
| Exploitation Route | The experimental data, parameters and models produced out of this project are of high value to academics and researchers working worldwide on high temperature metallic materials. The development of fully coupled diffusion-deformation and crack growth models is new and of immediate interest to researchers in the international context. Particularly, we have been exchanging the results with our contacts in US, China, France, Ireland and Germany. The impact of key scientific findings is facilitated by publications in appropriate journals and major international conferences in the relevant fields. Dissemination within the UK includes attendance of industry-orientated national conferences on high temperature fatigue, creep and materials. Our researchers also have been presenting the work at regional and national seminars and workshops to promote the uptake of our research findings by users. Certainly, these activities will be continued well beyond the completion of the project. This research studied critical mechanical and environmental variables that influence crack growth rates of advanced alloys in arduous high temperature environments. Specifically, it is fundamental research that tackles the issue of oxidation-assisted crack growth. The research outcomes have important applications in major industries including power generation plants, nuclear reactors and aerospace striving to achieve high-efficiency power and energy systems in response to climate change. This includes optimisation of service conditions and material microstructures for the achievement of maximum service life. The models and numerical tools that have been developed should also enable cost and resource reduction in product development stage. Again, exploitation of the project outcomes will be continued through our established industrial network. |
| Sectors | Aerospace, Defence and Marine,Energy,Other |
| URL | http://www.lsw-oxidation.com/ |
| Description | Exploitation of our research outcomes has been attempted by our project partners in the energy and aerospace industries (Uniper Energy, GE Power, dstl and NASA). GE power has circulated our results within their relevant departments, and also collected and stored our test data in their internal system to support component designers, material developers and structural integrity assessment teams. Uniper energy is planning to exploit the modelling approach for life management and performance assessment of their turbine components. A follow-up Royal-Society industrial fellowship is under consideration for Prof Zhao, the lead investigator of the project, in terms of carrying out one or two-year secondment at Uniper energy to further promote such activities. Also dstl and Rolls-Royce have played active roles in dissemination and exploitation of our research findings for other end users, particularly the physical examination of oxidation damage near a crack tip and the predictive modelling tools for crack growth under fatigue-oxidation conditions. These activities will be continued through extended collaborations with these key industrial partners. |
| First Year Of Impact | 2015 |
| Sector | Aerospace, Defence and Marine,Education,Energy |
| Impact Types | Societal,Economic |
| Description | GE power |
| Organisation | General Electric Power |
| Country | United Kingdom |
| Sector | Private |
| PI Contribution | Experimental and computational study of fatigue-oxidation damage and crack growth of single crystal and directionally solidified superalloys for gas turbines in power generation. |
| Collaborator Contribution | Supply of materials and technical advice; attendance of project review meetings. |
| Impact | Conference and journal publications |
| Start Year | 2013 |
| Description | NASA |
| Organisation | National Aeronautics and Space Administration (NASA) |
| Country | United States |
| Sector | Public |
| PI Contribution | Experimental and computational study of critical fatigue-oxidation damage of NASA superalloy LSHR for application in gas turbines. |
| Collaborator Contribution | Supply of materials and technical advice. |
| Impact | Journal and conference publications. |
| Start Year | 2013 |
| Description | dstl |
| Organisation | Defence Science & Technology Laboratory (DSTL) |
| Country | United Kingdom |
| Sector | Public |
| PI Contribution | Provide guidance for life assessment of gas turbines |
| Collaborator Contribution | Providing technical advice and attending project review meetings. |
| Impact | Journal and conference publications |
| Start Year | 2013 |
| Description | Open day |
| Form Of Engagement Activity | Participation in an open day or visit at my research institution |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Public/other audiences |
| Results and Impact | Public audience showed interest and impress in our research Promoted the profile of School, University and UK research |
| Year(s) Of Engagement Activity | 2014,2015,2016,2017 |
| Description | Website |
| Form Of Engagement Activity | A magazine, newsletter or online publication |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Public/other audiences |
| Results and Impact | Website promoted a share of our research activities, methodologes and results Promoted global awareness of the research achievements |
| Year(s) Of Engagement Activity | 2015 |
| URL | http://www.lsw-oxidation.com/ |