DISLOCATIONS AND THE STRENGTH OF POLYCRYSTALLINE CERAMICS
Abstract
The interaction of dislocations with grain boundaries in polycrystalline rock salt structure ceramics at various temperatures is discussed. At high temperatures, dislocations are mobile and able to cross slip freely to produce macroscopically wavy slip traces. Polycrystalline material then deforms plastically and necks down to a typical cup-cone ductile fracture. At intermediate temperatures, dislocations are less mobile and cross slip occurs on a microscopic scale within straight slip bands. Polycrystalline material can then deform plastically but the limited number of slip systems operating in the vicinity of grain boundaries results in a high rate of work hardening and the development of internal constraints. Brittle cleavage fracture originates from an intergranular source. At low temperature, cross slip within straight slip bands is restricted. Polycrystalline material cannot then deform plastically at all. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1962
- Accession Number
- AD0275273
Entities
People
- C.h. Li
- R.j. Stokes
Organizations
- Honeywell International, Inc.