A unified dependence of dislocation creep on water fugacity in clinopyroxene

Water weakening of clinopyroxenite in diffusion creep

[1] We performed triaxial compressive creep tests to study water weakening of clinopyroxenite in the diffusion creep regime. All tests were carried out on fine-grained samples at confining pressures between 100 and 300 MPa at temperatures of 1321 to 1421 K for water-saturated and 1398 to 1508 K for anhydrous conditions. Samples were prepared by hot-pressing ground powder of Sleaford Bay clinopy...

Dislocation mechanisms of creep in Ni3Al

The compressive creep deforrn;~tiort microstructure of polycrystalline Ni3AI h:is been observed by transnlission electron microscopy (TEM). ( 1 1 I ) rind ( 110) slip systems have been identified in primary creep. Dissociatiort of edge superparti:~l pairs perpendicular to the slip plane (both { 11 1 ) and ( 110) ) is common in crept specimens. I'he formation of this superdislocation...

Dislocation jamming and andrade creep.

We simulate the glide motion of an assembly of interacting dislocations under the action of an external shear stress and show that the associated plastic creep relaxation follows Andrade's law. Our results indicate that Andrade creep in plastically deforming crystals involves the correlated motion of dislocation structures near a dynamic transition separating a flowing from a jammed phase. Simu...

Creep Deformation by Dislocation Movement in Waspaloy

Creep tests of the polycrystalline nickel alloy Waspaloy have been conducted at Swansea University, for varying stress conditions at 700 °C. Investigation through use of Transmission Electron Microscopy at Cambridge University has examined the dislocation networks formed under these conditions, with particular attention paid to comparing tests performed above and below the yield stress. This pa...

Particle Rearrangement and Dislocation Creep in a Snow-densification Process