Micromechanical modeling of microstructural damage in creeping alloys. Final report

Technical Report · Thu Nov 15 04:00:00 EST 1984

OSTI ID:6225850

Argon, A S

Fracture under service conditions at high temperatures in structures undergoing creep deformation is intergranular. Cavities on grain boundaries are produced on interfaces of hard particles during transient sliding of grain boundaries. The growth of grain boundary cavities by a combination of continuum creep and diffusional flow is often constrained by the creep deformation of the surrounding grain matrix. The constrained growth and linking of grain boundary cavities produces isolated cracked grain boundary facets which continue to grow by continuum creep and in the process accelerate overall creep flow. Cracked grain boundary facets are the principal form of creep damage, and their density per unit volume can be taken as the parameter characterizing creep damage. This damage parameter can be incorporated into three-dimensional constitutive relations of creep deformation, and these relations can be used in large strain finite element programs to solve complex engineering problems of creeping structures. All the microstructural mechanics that enter into the above description have been verified in a selection of key experiments on cavitation and crack growth.

• Research Organization: Massachusetts Inst. of Tech., Cambridge (USA). Dept. of Mechanical Engineering
• DOE Contract Number: AC02-77ER04461
• OSTI ID: 6225850
• Report Number(s): DOE/ER/04461-7; ON: DE85003925
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
CAVITIES
CRACK PROPAGATION
CREEP
CRYSTAL STRUCTURE
DAMAGE
FAILURES
FRACTURES
GRAIN BOUNDARIES
MECHANICAL PROPERTIES
MICROSTRUCTURE