Three-dimensional characterization of fatigue-relevant intermetallic particles in high-strength aluminium alloys using synchrotron X-ray nanotomography

Abstract

International audienceSecond-phase particles and small porosities are known to favour fatigue crack initiation in high-strength aluminium alloys 2050-T8 and 7050-T7451. Using high-resolution X-ray tomography (320 nm voxel size), with Paganin reconstruction algorithms, the probability that large clusters of particles contain porosities could be measured for the first time in 3D, as well as precise 3D size distributions. Additional holotomography imaging provided improved spatial resolution (50 nm voxel size), allowing to estimate the probability of finding cracked particles in the as-received material state. The extremely precise 3D shape (including cracks) as well as local chemistry of the particles has been determined. This experiment enabled unprecedented 3D identification of detrimental stress risers relevant for fatigue in as-received aluminium alloys

On strain and damage interactions during tearing: 3D in situ measurements and simulations for a ductile alloy (AA2139-T3)

“…With the recent developments in 3D imaging techniques such as synchrotron tomography it has become possible to follow and quantify damage processes in situ at micrometer resolutions [23]. Even nondestructive observations at resolutions of tens of nanometers are now possible [24,25]. In situ tomography is limited to axisymmetric (or stick-like) specimens with diameters of the order of 1 mm, which, in practice, may be relaxed by a factor of 3 to 5 if local tomography can be used [26].…”

FCG Modelling Considering the Combined Effects of Cyclic Plastic Deformation and Growth of Micro-Voids

“…There are technological processes which favour the presence of defects, namely additive manufacturing, casting and welding. Additionally, second-phase particles favour the formation of pores [ 45 ]. Finally, the anti-clockwise rotation of the da/dN- Δ K curve may be seen as indirect proof of the presence of micro-voids.…”

Recent Progress of Synchrotron X-Ray Imaging and Diffraction on the Solidification and Deformation Behavior of Metallic Materials

“…Based on the loading type, these devices can be categorized into in situ tensile loading, axial fatigue loading, [112] rotary bending, et cetera; based on the loading environment, they can be ambient temperature, cryogenic, hightemperature, vacuum, et cetera. Some renowned researchers in the field include Professor Buffière et al [113][114][115][116][117][118] from Institut National des Sciences Appliquées de Lyon, France, Professor Toda et al [119][120][121][122][123][124] from Kyushu University, Japan, Professor Bale et al [125,126] from the University of California, United States, Professor Withers et al [127][128][129][130][131][132] from the University of Manchester, United Kingdom, and Professor Wu et al [133][134][135] from Southwest Jiaotong University, China. A summary of their contribution to the field is listed in Table 1.…”