Interface dislocations in superalloy single crystals

Journal Article · Tue Jun 22 00:00:00 EDT 1999 · Acta Materialia

DOI:https://doi.org/10.1016/S1359-6454(99)00092-0· OSTI ID:6443113

Probst-Hein, M; Eggeler, G ^[1]; Dlouhy, A ^[2]

---

1. Ruhr-Univ. Bochum (Germany). Inst. fuer Werkstoffe
2. Inst. of Physics of Materials, Brno (Czech Republic)

The overall stress state in [gamma]-channels of [gamma]/[gamma][prime]-microstructures has three components misfit stresses (due to [gamma]/[gamma][prime]-misfit), dislocation stress fields and the external stress. In the present study glide and climb forces on [gamma]-channel dislocations (from one slip system a[sub 0]/2[01[bar 1]](111)) are studied calculating Peach-Koehler forces for [gamma]/[gamma][prime]-interface dislocations exposed to the overall stress state. A thermo-elastic finite element calculation of misfit stresses is performed and the results are used as one input into a simplified discrete dislocation model (DDM). The influence of [gamma][prime]-volume fraction and dislocation density in the [gamma]-channels is explicitly considered. The calculations were motivated by previous mechanical and microstructural investigations in which elementary dislocation processes were identified by transmission electron microscopy as part of the mechanism of high temperature and low stress creep. The results help to interpret phenomenological concepts (like build up of back stress) and rationalize microstructural findings (like dislocation network spacings).

• OSTI ID: 6443113
• Journal Information: Acta Materialia, Vol. 47:8; ISSN 1359-6454
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPUTERIZED SIMULATION
CREEP
DISLOCATIONS
FINITE ELEMENT METHOD
INTERFACES
MICROSTRUCTURE
NICKEL BASE ALLOYS
STRESSES
TEMPERATURE DEPENDENCE
ALLOYS
CALCULATION METHODS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
LINE DEFECTS
MECHANICAL PROPERTIES
NICKEL ALLOYS
NUMERICAL SOLUTION
SIMULATION
360102* - Metals & Alloys- Structure & Phase Studies
360103 - Metals & Alloys- Mechanical Properties