A Model for Steady State Creep Based on the Motion of Jogged Screw Dislocations*
نویسنده
چکیده
ob ps est la densite en dislocations-vis mobiles, D le coefficient d’autodiffusion, a le nombre d’atomes parcellule unitaire, h le vecteur de Burgers, c(,, le parametre reticulaire et I la distance moyenne entre les trans. Dans le but de comparer oette relation aux r&&tats experimentaux on a determine la loi de variation de ps avec la tension appliquee pour un alliage Fe + 3.0 oA Si. On a obtenu la relation suivante:
منابع مشابه
ATOMISTIC STUDIES OF JOGGED SCREW DISLOCATIONS IN y-TIAL ALLOYS
The behavior of jogged screw dislocations in y-TiAl alloys has been investigated with large-scale molecular dynamics (MD) simuIations. We find a new mechanism for formation of pinning points in jogged screw dislocations. We also find that the critical height for the jogs in the +[i10] directions on the (001) plane to move nonconservatively is between 3ro and 4r0, where ro is the nearest neighbo...
متن کاملUnderstanding Creep—a Review
A simple model based on the Orowan equation and the dynamic evolution of the dislocation structure by generation and merging of slipped areas is used to see which experimental results on creep of pure and solute-hardened crystalline materials can or cannot be explained with regard to creep with refinement or coarsening of the dislocation structure and steady-state creep. Quantitative deficienci...
متن کاملEffect of Reversed Cyclic Stressing and Phase Transition on the Transient and Steady State Creep Behaviour of Al–22 wt% Ag Alloy
Static and completely reversed cyclic creep acceleration characteristics of Al – 22 wt% Ag alloy were investigated using a modified tensile testing machine. Different amplitudes of reversed cyclic stress (σrev) ranging from 7.2 to 10.2 MPa at different working temperatures ranging from 353 K to 413 K were performed. To get a relation between aging temperature and threshold stress (σth) for cycl...
متن کاملDevelopment of Mathematical Model for Controlling the Drilling Parameters with a Screw Downhole Motor
Article presents results of study on possibility of increasing the efficiency of drilling directional straight sections of wells using screw downhole motors (SDM) with a combined method of drilling with rotation of drilling string (DS). Goal is to ensure steady-state operation of SDM with simultaneous rotation of DS by reducing the amplitude of oscillations with adjusting the parameters of dril...
متن کاملTensile Creep of Polycrystalline Near-Stoichiometric NiAl
Long term tensile creep studies were conducted on binary NiAl in the temperature range 700-1200 K with the objectives of characterizing and understanding the creep mechanisms. Inverse and normal primary creep curves were observed depending on stress and temperature. It is concluded that the primary creep of NiAl is limited by dislocation mobility. The stress exponent for creep, n, decreased fro...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2002