The dynamic behavior of three high manganese steels with very different stacking faultenergy (SFE) values (4-30 mJ/m2) were studied using high strain rate torsional tests. The hotrolledmicrostructure of the steel with the lowest SFE of 4 mJ/m2 consisted of a duplex mixture ofaustenite and ε-martensite, but those of the other two steels were fully austenitic. The deformedmicrostructures were stu...

High-entropy alloys (HEAs) are a new class of multi-component alloys that exhibit surprising characteristics, [1] including very large strain hardening rates, large fracture toughness at room temperature [2], and a strong temperature dependence of yield strength at or below room temperature. These properties are closely linked to nano-twinning and dislocation-mediated plasticity, yet little exp...

We show in this work that the mechanical properties of molecular crystals are strongly affected by the flexibility of the constituent molecules. To this end, we explore several kinematically restrained models of the molecular crystal cyclotrimethylene trinitramine in the α phase. We evaluate the effect of gradually removing the flexibility of the molecule on various crystal-scale parameters suc...

The previous work of Professor W. G. Burgers and Dr. A. J. Bogers is used to develop a mechanism of strain-induced martensitic nucleation, involving two intersecting shear systems. We distinguish between strain-induced nucleation and stressassisted nucleation, the latter involving the same sites and embryos as does the regular spontaneous transformation. The strain-induced nucleation, on the ot...

We study the coherent and semi-coherent Al/α-Al2O3 interfaces using molecular dynamics simulations with a mixed, metallic-ionic atomistic model. For the coherent interfaces, both Al-terminated and O-terminated nonstoichiometric interfaces have been studied and their relative stability has been established. To understand the misfit accommodation at the semi-coherent interface, a 1-dimensional (1...

Ideal strength, which can be defined as the stress necessary to induce permanent deformation in a material without prior imperfections, is one of the important materials characterizations. In this study we calculate the ideal pure shear and simple shear strengths of fcc (Al, Cu, Ni, Ag) and bcc (Fe, Mo, W) metals in their common slip systems using density functional theory. We find the critical...

Hydrogen diffusion and its interaction with dislocations play an important role in hydrogen embrittlement, however, such a process multiple-principal high entropy alloys (HEAs) is still elusive. Here, first-principles calculations were performed to investigate the solution of effect on stacking fault energy FeCoNiCrMn. It shown that unique lattice distortion HEAs causes wide distribution local ...