The effects of hydrostatic extrusion on particle cracking and on the subsequent tensile properties of some prototypical particlereinforced metal–matrix composites are investigated. In most cases, tensile failure occurs through a plastic instability in accordance with the Considere criterion for necking. The corresponding failure strain is therefore dictated by the global flow and hardening char...

[1] Differential stresses in a cylindrical rock of polycrystalline Mg2SiO4 ringwoodite were measured at room temperature with pressures up to 10 GPa, axial strains in excess of 20%, and strain rates between 5 10 5 and 4 10 6 s , using the deformation-DIA coupled with monochromatic X-rays. The sample exhibited ductile behavior in axial shortening-lengthening cycles with reproducible hysteresis l...

A split Hopkinson pressure bar is used to investigate the dynamic mechanical properties of biomedical 316L stainless steel under strain rates ranging from 1 × 10(3) s(-1) to 5 × 10(3) s(-1) and temperatures between 25°C and 800°C. The results indicate that the flow stress, work-hardening rate, strain rate sensitivity, and thermal activation energy are all significantly dependent on the strain, ...

Frictional normal contact probing methods involving instrumented, depth-sensing indentation can be used to estimate the mechanical properties of small-volume structures and materials such as thin films and components of micro-electro-mechanical systems. This paper describes a new method for estimating the plastic properties, i.e. the yield strength and strain hardening exponent, of ductile mate...

By analyzing the problem of high pressure torsion (HPT) in the rigid plastic formulation, we show that the power hardening law of plastically deformed materials leads to self-similarity of HPT, admitting a simple mathematical description of the process. The analysis shows that the main parameters of HPT are proportional to β q , with β being the angle of the anvil rotation. The meaning of the p...

Full-field quantitative strain maps of phase transformation and plasticity in Nitinol under large sheardominated deformation are presented. To achieve a sheardominated deformation mode with relatively uniform stresses and strains, a shear compression specimen (SCS) geometry was utilized. Shear deformation appears to impede the development of the strain localization during phase transformation t...

This paper presents a new formulation of a well known double hardening model often referred to as the Hardening Soil model. As an alternative to the existing Hardening Soil model’s Mohr-Coulomb failure surface, the new formulation allows for the incorporation of smooth failure surfaces, such as the failure surface proposed by Matsuoka & Nakai or that proposed by Lade & Duncan. Although the inco...

A strong strain rate dependence on the crystallographic texture of oxygen-free high conductivity copper is observed and reported for the first time. Two shear compression specimens were deformed at widely different strain rates (0.001 s 1 and 7000 s ) to the same strain, and their textures were determined using orientation image microscopy. By comparing the stress–strain curves and the major te...

The tensile deformation response and texture evolution of aluminum alloyed Hadfield steel single crystals oriented in the h169i direction is investigated. In this material, the strain hardening response is governed by the high-density dislocation walls (HDDWs) that interact with glide dislocations. A microstructure-based visco-plastic self-consistent model was modified to account for mechanical...

This article addresses the issue of reproducing quantitative pressure-drop predictions for constant shear-viscosity fluids in contraction and contraction/expansion flow geometries. Experimental observations on pressure-drop for severe strain-hardening Boger fluids reveal significant enhancement above Newtonian fluids in axisymmetric but not planar configurations. This discrepancy has eluded pre...