Application of Advanced Residual Stress Measurement Methods in Failure Analysis
Nan Li1*, Xi Wang1, Jun Luo1, Gang Li2, Changkui Liu1*
1AECC Beijing Institute of Aeronautical Materials, Beijing 100095, China
2 CAS The Institute of High Energy Physics, Beijing 100039, China
EXTENDED ABSTRACT: Aero-engine technology is an important driving force for the development of national aviation industry and the progress of major safety projects. Its high thrust-weight ratio demands increasingly large and complex key load-bearing components, and the internal residual stress becomes prominent in its manufacturing and service process. Such materials possess complex structure, multiphase, coarse grain size, significant anisotropy, and complex component shapes with thin wall, hollow structure (such as blade, casing), or thick structure (such as turbine disc, bearing), which leads a difficult to detect internal residual stress by conventional means. Beijing Institute of Aeronautical Materials and Institute of CAS The Institute of High Energy Physics have cooperated to develop and research diffraction imaging technology using high resolution characteristics of synchrotron radiation. The electron cloud density in the material was analyzed and studied via collecting, extracting, reconstructing, and analyzing all the contrast information. Meanwhile, the diffraction contrast information was paired and indexed, and the high-throughput and rapid characterization of the residual stress distribution in the microstructure of single crystal superalloy was realized. In addition, combined with the microstructure characteristics of materials, X-ray stress testing technology was studied for single crystal materials, casting coarse crystal materials, deformation texture materials, etc., and nondestructive residual stress detection based on laboratory was realized. More importantly, the residual stress is applied to the failure analysis, such as cracking of welding conduit, cracking of propeller blade, cracking of clutch housing, etc. Through the analysis of the residual stress, we can judge the stress of the corresponding position of the component, and provide critical data support for welding, heat treatment and surface strengthening process optimization of related parts.
Nan Li, has completed her PhD from Beijing Institute of Technology. She used to be visiting scholars in the University of Tennessee, Argonne National Lab in US and the University of Manchester in UK. She is a senior engineer of AECC Beijing Institute of Aeronautical Materials, Failure Analysis Center of AVIC / AECC and Mechanical Failure Analysis Center of COMAC. Her research interests include detection and characterization of metal and alloys, structural damage behavior and life prediction, residual stress measurement methods, failure analysis and prevention, etc. She has published more than 20 academic papers, 2 Published books.