A multi-scale study of the interaction of Sn solutes with dislocations during static recovery in α-Fe

Abstract

The properties of engineering materials can be improved by optimising the microstructural developments during annealing processes. Here, we investigate the effect of Sn on the recovery annealing of cold rolled Fe-3%Si alloys. We use a multiscale approach combining micro hardness, electron back scattering diffraction (EBSD), and dark field X-ray microscopy (DFXM): a recent, nondestructive synchrotron-based technique that allows 3D mapping of orientation and lattice strain within individual grains embedded in bulk samples. Micro hardness results show that the Sn solute has a strong effect on the recovery kinetics. These results are compared to a physical kinetic model suggesting that Sn limits the softening. This observation is further discussed by a complementary atomistic modelling that demonstrates solute-dislocation interaction around edge dislocations. In situ DFXM experiments reveal the 3D microstructural evolution upon annealing at the grain level with high angular resolution. The DFXM observations show that Sn slows the recovery kinetics within individual grains, in agreement with the other microscopic investigations. Furthermore, the DFXM results provide a direct observation of strain fields around dislocation loops in an embedded single grain, which is argued to remain static due to solute effect during recovery.

Abnormal Shear Performance of Microscale Ball Grid Array Structure Cu/Sn–3.0Ag–0.5Cu/Cu Solder Joints with Increasing Current Density

“…Specifically, the athermal effect of current stressing favors producing dislocations as a result of electronlattice interaction, thus inducing lattice stress, but Joule heating favors relaxing the stress, resulting in a dynamic recovery of dislocations, which can be considered as a stress relaxation process controlled by the thermal-activated mechanism [51]. When Joule heating is generated, lattice stress in the solder matrix will be lowered; the correlation between lattice stress and temperature is as following [52]:…”

Segregation of Sn on migrating interfaces of ferrite recrystallisation: quantification through APT measurements and comparison with the solute drag theory

“…Both Si and Sn concentrations are within the solid solubility values in α-Fe. The materials were processed with cold rolling to a total cold work -Von Mises true strain of about ε = 2 as described elsewhere 19 . Materials in the as deformed state, were subjected to a static recrystallisation annealing at 973K in a BAHR dilatometer, to achieve a partially recrystallized microstructure.…”

Geometrical-optics formalism to model contrast in dark-field X-ray microscopy

“…The first dedicated darkfield X-ray microscope was recently installed on beamline ID06 of the European Synchrotron Radiation Facility (ESRF) (Kutsal et al, 2019). Since its installation, the microscope at ID06 has been used to study domain evolution in ferroelectrics (Simons et al, 2018), the austenitic transformation in shape-memory alloys (Bucsek et al, 2019), recovery in metals (Mavrikakis et al, 2019;Ahl et al, 2020), embedded particles in steel (Hlushko et al, 2020), visualization of dislocation structures (Jakobsen et al, 2019;Dresselhaus-Marais et al, 2021) and the structure of biominerals (Cook et al, 2018). For related work at beamline ID01 of ESRF, see Hilhorst et al (2014) and Zhou et al (2018).…”