| About this Abstract |
| Meeting |
2022 TMS Annual Meeting & Exhibition
|
| Symposium
|
Environmentally Assisted Cracking: Theory and Practice
|
| Presentation Title |
On the Critical Role of Localized Oxidation Processes in High Temperature Failures under Cyclic Thermomechanical Loading Conditions |
| Author(s) |
Yanfei Gao |
| On-Site Speaker (Planned) |
Yanfei Gao |
| Abstract Scope |
Alloy materials subjected to cyclic thermomechanical conditions are oftentimes analyzed from damage mechanics approaches, which however bear no direction condition to the detailed failure processes. Motivated by the oxidation finger formation under isothermal and cyclic oxidation conditions, this work proposes that localized oxidation processes, together with the stress generation from concomitant oxidation-creep-diffusion processes, dictate the failure initiation in a wide range of experimental observations. Oxidation fingers or pegs under cyclic thermomechanical loading conditions can extend into the superalloy substrate or expand laterally, contingent on the extent of plastic yield in these geometric defects. It is found that an extended holding at high temperature promotes the development of a large tensile stress in the superalloy substrate and thus stabilizes/suppresses the growth of such defects. Insights from these theoretical studies will be compared to some recent experiments for turbine materials. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
High-Temperature Materials, Mechanical Properties, |