TEM characterization of dislocations in TiB2 particles after hypervelocity impact.
Micron
; 67: 96-99, 2014 Dec.
Article
en En
| MEDLINE
| ID: mdl-25108104
ABSTRACT
Characteristic of dislocations in TiB2 particles associated with hypervelocity impact craters in 65 vol.% TiB2/Al composite were investigated by transmission electron microscopy (TEM). Two kinds of dislocation networks in as-impacted TiB2 particles were identified. One is hexagonal dislocation networks including 1/3ã1Ì21Ì0ã, ã0001ã, 1/3ã1Ì21Ì3ã type dislocations on {0001}, {101Ì0}, and {123Ì0} planes. Another one is the hexagonal dislocation networks including 1/3ã112Ì0ã, ã0001ã, and 1/3ã112Ì3ã type dislocations on {0001}, {101Ì0}, and {11Ì00} planes. Formation of dislocation network should be contributed to the parallel sets of "a" type dislocations (1/3ã112Ì0ã or 1/3ã1Ì21Ì0ã type dislocations) reacting with parallel sets of "b" type dislocations (ã0001ã type dislocations) to form "c" type dislocations (1/3ã112Ì3ã or 1/3ã1Ì21Ì3ã type dislocations). Moreover, dislocations reaction processes do not result in an energy reduction, and are called quasi-equilibrium configurations. Formation of dislocations may result from high temperature or pressure generated by hypervelocity impact. During the cooling from high temperature and unloading from high pressure, dislocations in TiB2 particles rearranged and transformed to dislocation networks to lower the defect energy.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Micron
Asunto de la revista:
DIAGNOSTICO POR IMAGEM
Año:
2014
Tipo del documento:
Article