The physical properties of materials

Bubbles formation in helium ion irradiated Cu/W multilayer nanocomposites: Effects on structure and mechanical properties

“…In nanocrystalline metals, grain boundary sliding and dislocations gliding are the key factors affecting deformation mechanisms and strength [31] and their alteration have significant effects on the resulting mechanical behaviour. Formation of He bubbles both at interfaces and in the grain interior have opposite effects on strength.…”

The role of anharmonicity in a variety of phase transitions controlled by pressure, including melting, brittle-to-ductile transition, and the liquid-vapour critical point

“…Now, in fracture theory, it is known (see Ref. [15], p. 291) that when hydrogen collects in microcracks it exerts an internal pressure, P , which may be added directly to the external stress σ to produce a total stress (P + σ) for propagation. In determining the effect of hydrostatic pressure on the transition temperature, we can apply this result by adding it to the external stress leading to…”

Mechanics of Shape Memory Alloy Materials – Constitutive Modeling and Numerical Implications

“…For the past decades several constitutive models have appeared within the literature (e.g., Raniecki et al, 1992;Abeyaratne and Knowles, 1993;Ivshin and Pence, 1994;Boyd and Lagoudas, 1996;Lubliner and Auricchio, 1996;Panoskaltsis et al, 2004), which within the context of a geometrical linear theory can capture several aspects of the experimentally observed response. Nevertheless, the physics of the problem (e.g., see Smallman and Bishop, 2000), together with some basic results of the crystallographic theory of martensitic phase transformations (e.g., Ball and James, 1987;James and Hane, 2000;Abeyaratne et al 2001), suggest that a geometrically non -linear approach is more appropriate. Levitas and Preston, (2005) discuss the drawbacks of the infinitesimal models and they report that finite rotations of the crystal lattice can occur at small transformation strains (small strains and finite rotations) and can crucially affect the phase transformation conditions.…”

“…The mechanisms of this recovery are either a diffusionless transformation between the austenite phase (which is a highly ordered phase and is also called the parent phase) and the martensite phase (which is a less ordered one) or the reorientation (detwinning) of martensite variants. Detailed exposures to the physics of the subject may be found in Wayman (1964), Smallman and Bishop (2000) and Bhattacharya (2003). As is shown in these studies the thermomechanical response of SMAs is extremely complex, a fact that in conjunction with the continuously increasing use of SMAs in several innovating applications in many engineering fields results in a greater need for a better understanding of these materials.…”