X ray attenuation measurements for high-temperature materials characterization and in-situ monitoring of damage accumulation. Ph. D. Thesis - Cleveland State Univ. , 1991
The scope of this dissertation is to develop and apply x ray attenuation measurement systems that are capable of: (1) characterizing density variations in high-temperature materials, e.g., monolithic ceramics, ceramic and intermetallic matrix composites, and (2) noninvasively monitoring damage accumulation and failure sequences in ceramic matrix composites under room temperature tensile testing. This dissertation results in the development of: (1) a point scan digital radiography system, and (2) an in-situ x ray material testing system. Radiographic evaluation before, during, and after loading shows the effect of preexisting volume flaws on the fracture behavior of composites. Results show that x ray film radiography can monitor damage accumulation during tensile loading. Matrix cracking, fiber matrix debonding, fiber bridging, and fiber pullout are imaged throughout the tensile loading of the specimens. Further in-situ radiography is found to be a practical technique for estimating interfacial shear strength between the silicon carbide fibers and the reaction bonded silicon nitride matrix. It is concluded that pretest, in-situ, and post test x ray imaging can provide for greater understanding of ceramic matrix composite mechanical behavior.
- Research Organization:
- National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center
- OSTI ID:
- 7047837
- Report Number(s):
- N-92-25996; NASA-TM--105577; E--6652; NAS--1.15:105577; CNN: RTOP 510-01-50
- Country of Publication:
- United States
- Language:
- English
Similar Records
In situ X-ray monitoring of damage accumulation in SiC/RBSN tensile specimens
X-ray attenuation measurements for high-temperature materials characterization and in-situ monitoring of damage accumulation
Related Subjects
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
360602* -- Other Materials-- Structure & Phase Studies
42 ENGINEERING
420500 -- Engineering-- Materials Testing
CARBIDES
CARBON COMPOUNDS
CERAMICS
COMPOSITE MATERIALS
CRACK PROPAGATION
DAMAGE
DEFORMATION
DENSITY
FAILURE MODE ANALYSIS
FIBERS
FRACTURE PROPERTIES
IN-SITU PROCESSING
INDUSTRIAL RADIOGRAPHY
MATERIALS
MATERIALS TESTING
MECHANICAL PROPERTIES
MECHANICAL TESTS
MONITORING
NITRIDES
NITROGEN COMPOUNDS
NONDESTRUCTIVE TESTING
PERFORMANCE
PHYSICAL PROPERTIES
PNICTIDES
PROCESSING
RADIATION ATTENUATION TESTING
SILICON CARBIDES
SILICON COMPOUNDS
SILICON NITRIDES
SYSTEM FAILURE ANALYSIS
SYSTEMS ANALYSIS
TESTING
USES
X-RAY RADIOGRAPHY