The Air Force Research Laboratory has conducted a study on metal fatigue in aircraft components to learn more about microscopic crack formations and their possible effects on aircraft safety.
The metals branch of the lab’s materials and manufacturing directorate investigated the early stages of crack formation in turbine engine materials to find ways to reduce cracks that could potentially cause fatigue failure, the U.S. Air Force said Thursday.
“The Air Force routinely inspects engine components for cracks, but it is possible to miss microscopically small cracks with current inspection methods,” said Adam Pilchak, an AFRL research scientist with the metals branch.
“Because crack growth rates can vary considerably depending on how a material is processed, it is important to understand the worst-case scenario that leads to the shortest fatigue lifetime.”
The service branch noted factors that cause metal fatigue in an aircraft’s engine, wing or tail structures include repeated loading and unloading, air pressure changes and altitude exposure.
The study sought to build on understanding of metal fatigue, crack origins and the materials on which cracks form to foster updates on aircraft inspection procedures that work to help maintainers discover metal fatigue at an earlier stage before it could impact safety.
The Air Force added that the study also aimed to show whether there is a need to modify the way materials are processed.
The team employed a scanning electron microscope that worked to magnify the surfaces of fractured aircraft engine components in an effort to determine crack origins.
The study led the team to win first place in the electron microscopy research category at the International Metallographic Contest at Microscopy and Microanalysis 2016 and the Jacquet-Lucas Award for excellence in metallography.