Revealing Hidden Defect Interactions in Engineering Alloys at the Microscale
Abstract
The proposed research aims to bridge our understanding of bulk defect motion in engineering alloys between static microscopy imaging and macroscopic mechanical testing by experimentally revealing previously ‘hidden’ plastic deformation-induced defect reconfigurations. This goal is achieved through novel multiscale in-situ measurements of X-ray scattering, including weak (diffuse) scattering fluctuations, in individual embedded grains during continuous thermomechanical loading. With this ability to directly probe subsurface defect structures in-situ, defect evolution pathways can be directly connected to micromechanical behaviors. These measurements are made possible by recent advances in loading devices, X-ray detection technologies, and application of machine learning at synchrotron X-ray light sources. The proposed experimental approach is applied to understanding cold dwell fatigue behavior in titanium alloys and in particular, testing various theories regarding the origins of failure nucleation due to creep-driven defect reconfigurations. Experimentally validated theory will lead to the development of safer and more cost-effective best practices for use of titanium alloys by the Air Force. Understanding gained from this research will also lead to the development of superior alloy systems for next-generation air- and spacecraft.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 07, 2023
- Source ID
- FA95502110254
Entities
People
- Darren C Pagan
Organizations
- Air Force Office of Scientific Research
- Pennsylvania State University
- United States Air Force