Nondestructive crack size and interfacial degradation evaluation in metal matrix composites using ultrasonic microscopy
- Univ. of Dayton, OH (United States). Research Inst.
- Wright Lab., Wright Patterson AFB, OH (United States)
Ultrasonic scanning acoustic microscopy is a nondestructive method useful for material elastic property quantification as well as crack size determination for surface and subsurface cracks. The advantage of the method over destructive methods for crack size determination is that the imaging technique can provide the crack sizing information while helping in the detection of interface degradation and early crack initiation so that their growth can be monitored during interrupted fatigue tests. Various metal matrix composite systems with titanium based matrix and SCS-6 fibers have been evaluated for this study [Ti-24Al-11Nb (atomic percent), Ti-6Al-2Sn-4Zr-2Mo (weight percent), and Ti-15Mo-3Nb-3Al-0.2Si (weight percent)]. The scanning acoustic microscope technique has been applied to materials subjected to both room temperature and elevated temperature fatigue cycling in addition to thermomechanical fatigue (in-phase and out-of-phase) conditions. A 50 MHz scanning acoustic microscope has been used for the imaging and evaluation of the damage initiation and growth of surface/subsurface cracks and interfacial degradation. All the images have been produced by exploiting the surface wave component of the ultrasonic signals from the scanning acoustic microscope because of the higher sensitivity of surface waves to both surface/subsurface cracks and perhaps also due to the changes in interfacial elastic properties. The results shown in this paper provide a very good understanding of the crack initiation and growth as well as interfacial degradation process of titanium based metal matrix composites when subjected to cyclical stresses at elevated temperatures and room temperature. The results indicate that the combination of high temperature and stress is very severe to the interface between the matrix and the fiber.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 136487
- Report Number(s):
- CONF-9305422--
- Journal Information:
- American Society for Testing and Materials, Special Technical Publication, Journal Name: American Society for Testing and Materials, Special Technical Publication Journal Issue: 1251; ISSN 0066-0558; ISSN ASTTA8
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
42 ENGINEERING
ACOUSTIC MICROSCOPY
ALUMINIUM ALLOYS
COMPOSITE MATERIALS
CRACK PROPAGATION
CRACKS
DAMAGE
EXPERIMENTAL DATA
FATIGUE
FRACTURE PROPERTIES
INTERFACES
METALLOGRAPHY
MOLYBDENUM ALLOYS
NIOBIUM ALLOYS
RAYLEIGH WAVES
SILICON ADDITIONS
SILICON CARBIDES
STRESSES
TEMPERATURE DEPENDENCE
TIN ALLOYS
TITANIUM BASE ALLOYS
TRANSDUCERS
ZIRCONIUM ALLOYS