ISSN: 0884-6804
Page Count: 7

Residual Stresses in SCS-6/Ti-24Al-11Nb Composite: Part I—Experimental
Jayaraman, N
University of Cincinnati, OH

Rangaswamy, P
University of Cincinnati, OH

Revelos, WC
WL/MLLN, Materials Behavior and Processing Branch, Metals and Ceramics Division, Wright-Patterson AFB, OH

Abstract

Residual stress analysis of an as-received and thermally cycled SCS-6/Ti-24Al-11Nb (at.%) [0]⁸ metal matrix composite (MMC) was performed using the X-ray diffraction (sin²ψ) technique. Residual stresses were measured in the α² phase of the matrix in orientations parallel, transverse, and 45° to the fiber direction. Stress profiles were determined by successive removal of the matrix from the composite surface by electropolishing. Within 10 to 30 μm of the first fiber plane, the stress levels were found to be lower than those far from the fiber plane. Residual stress measurements performed on the matrix between the first two fiber rows revealed lower stress levels than those in the outermost matrix layers. The presence of stress gradients normal to the surface of the composite was also revealed. Measurement of residual stress levels in the composite subjected to thermal cycling from 150°C to 815°C in an inert atmosphere revealed almost complete stress relaxation after 500 cycles.

Keywords:
residual stress analysis, metal matrix composite (MMC), coefficient of thermal expansion (CTE), X-ray diffraction

Paper ID: CTR10394J
DOI: 10.1520/CTR10394J
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