The amount of cold work induced by a surface hardening technique and the depth to which it is produced within a metallic material are both important parameters within the field of surface engineering. In this paper a methodology of establishing reliable estimates of the depth and magnitude of cold work in surface hardened nickel-based superalloy si...
During the plastic deformation of metallic materials, part of expended mechanical energy diffuses as heat. The fraction of plastic work converted into heat is called the Taylor-Quinney Coefficient (TQC), which is often assumed to be a constant parameter of about 0.9. The remaining portion of the plastic work is called stored energy. The stored ener...
Short-range ordering (SRO), its evolution in the equiatomic Cr-Co-Ni medium-entropy alloy (MEA), and its effects on mechanical properties were investigated by, respectively, electrical resistivity measurements and tension and compression tests on single crystal specimens at room temperature and liquid nitrogen temperature. SRO below 973 K can be mo...
Neutron spectroscopy measurements have been performed on single crystals of the antiferromagnetic van der Waals compound NiPS$_3$. Linear spin wave theory using a Heisenberg Hamiltonian with single-ion anisotropies has been applied to determine the magnetic exchange parameters and the nature of the anisotropy. The analysis reveals that NiPS$_3$ is ...
Certaines phases d'iridate ont récemment attiré l'attention en raison de leur fort couplage spin-orbite associé à des fortes corrélations électroniques pouvant conduire à des propriétés physiques originales. Ainsi, la famille des pérovskites de type « Ruddlesden-Popper » présente trois composés aux propriétés intéressantes, avec des corrélations él...
Ductile fracture through void growth to coalescence occurs at the grain scale in numerous metallic alloys encountered in engineering applications. Classical models used to perform numerical simulations of ductile fracture, like the Gurson-Tvergaard-Needleman model and its extensions, are relevant for the case of large voids compared to the grain si...
Les cristaux dopés aux ions de terres rares sont des matériaux prometteurs pour le traitement de l’information quantique, grâce à la possibilité de réaliser des mémoires quantiques et des analyseurs spectraux large bande à basse température. De plus, il a récemment été démontré que le transfert de cohérence entre les spins électroniques et nucléair...
Published in International Journal of Materials Research
The structural evolution in NiTi shape memory alloys subjected to pseudoelastic cycling is examined in the present study. Single crystals with [100] and [111] orientations were subjected to repeated compressive cycles and then studied by transmission electron microscopy (TEM). TEM observations were made at cycle numbers 1, 2, 5, 10, and 20 since th...
Published in International Journal of Materials Research
Faceting and migration of twin tips in slightly deformed Zn [112̅0] flat single crystals have been investigated. The stationary shape of the slowly migrating tip of the twin plate has been studied, and the migration rate has been measured between 592 and 692 K in situ using polarized light. Below 632 and above 682 K, the twin tip contains only one ...
Classical crystal plasticity models fail to capture experimentally observed size effects, namely, the smaller the size the greater thestrength. These models also show spurious mesh dependency in strain localization problems due to the lack of a characteristiclength scale in the constitutive framework. Strain gradient crystal plasticity models can o...
