THE USE OF A BUBBLE MODEL TO STUDY STRESS-INDUCED MIGRATION AND SLIDING OF GRAIN BOUNDARIES.
Abstract
Stress-induced grain boundary sliding and migration was studied using a bubble model. Two important results emerge which, we believe, apply to boundaries in real crystals. First, sliding occurs by the propagation of grain boundary dislocations, which may have large burgers vectors, in the plane of the boundary; the magnitude of the burgers vector, and the pre-existing density of these dislocations in the boundary depends on the boundary angle and orientation. Second, migration is very like the process of crystal growth from the vapour: atoms leave or join one side of the boundary at steps; a boundary of which one side is a close-packed plane rarely migrated. The process of sliding periodically places atoms in a position which favours their leaving one side of the boundary and joining the other; this can result in sliding and migration which are proportional, and suggests a model for thermally activated grain-boundary sliding. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1968
- Accession Number
- AD0667589
Entities
People
- M. F. Ashby
- Raghu G. Raj
Organizations
- Harvard University