The Importance of Geometric Statistics to Dislocation Motion

Abstract

This paper presents the results of a computer simulation of a dislocation, under stress, gliding through a random array of point obstacles. Physically, the randomly distributed obstacles could represent solute atoms, forest dislocations, small precipitates, etc. For a constant applied stress the dislocation bypasses an obstacle either mechanically, when the force on the obstacle due to the line tension of the dislocation is greater than the obstacle strength, or thermally, after waiting a time determined in a Monte Carlo fashion. The average velocity of the dislocation is deduced as a function of applied stress, obstacle strength, and temperature. DISLOCATION; THERMAL ACTIVATION; DISLOCATION VELOCITY; RANDOM ARRAY OF OBSTACLES