Terence G. Langdon

TL;DR: In this article, a spray-cast Al-7034 alloy was processed by high pressure torsion (HPT) at temperatures of 293 or 473 K using an imposed pressure of 4 GPa and torsional straining through five revolutions.

TL;DR: In this article, the feasibility of using commercial purity (CP) titanium of grade 1 for dental implants after processing by equal-channel angular pressing (ECAP) was evaluated in tensile and compression testing and in fatigue.

TL;DR: In this paper, a deformation model for high temperature grain boundary sliding was proposed to predict the relationship between strain rate, flow stress, grain size, temperature and basic material properties such as the Burgers vector modulus, the shear modulus and the grain boundary diffusion coefficient.

TL;DR: In this article, the authors evaluated the significance of cavitation in tensile testing of a superplastic spray-cast Al-7034 alloy processed by equal-channel angular pressing (ECAP).

Abstract: Under creep conditions of high homologous temperatures and low stresses, crystalline solids exhibit Newtonian viscous flow so that the steady-state strain rates vary linearly with the applied stress and deformation occurs by the Nabarro—Herring and/or Harper—Dorn mechanisms. The characteristics of these two processes are examined with reference to apparent discrepancies in the interpretation of experimental data. Three basic requirements are formulated which, if satisfied, will permit an unambiguous identification of the occurrence of Harper—Dorn creep.