Residual stress measurements in an SiC continuous fiber reinforced Ti matrix composite

• Published in: Scripta materialia Vol. 42; no. 8; pp. 775 - 779
• Main Authors: Willemse, P.F, Mulder, F.M, Wei, W, Rekveldt, M.Th, Knight, K.S
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Ltd 14.04.2000; Elsevier Science
• Subjects: Analysing. Testing. Standards; Applied sciences; Composite; COMPOSITE MATERIALS; Exact sciences and technology; FIBERS; MATERIALS SCIENCE; Metals. Metallurgy; NEUTRON DIFFRACTION; Residual stress; RESIDUAL STRESSES; SAMPLE PREPARATION; SILICON CARBIDES; Stress analysis; TITANIUM BASE ALLOYS; X-RAY DIFFRACTION; X-ray diffraction; Composite; Neutron diffraction; Residual stress; Stress analysis; Silicon carbide; Fibre reinforced metal; Experimental study; X ray diffraction; Titanium base alloys; Composite material
• ISSN: 1359-6462; 1872-8456
• DOI: 10.1016/S1359-6462(99)00429-7

Residual stresses in the matrix of a continuous SiC fiber-Ti 1100 matrix composite sheet were measured by means of x-ray and neutron diffraction. The following conclusions can be drawn from the results of this investigation: The neutron diffraction experiments show that the bulk stress state within the matrix can be approximated by a biaxial tensor with a relatively large tensile component parallel to the fibers and a smaller tensile component within the sheet plane perpendicular to the fiber axes. A depth profile of the stresses parallel to and perpendicular to the fibers within the sheet plane as measured with x-ray diffraction, shows that, for this specimen, these stresses decrease with the distance from the original surface of the composite. At approx55 mu m below this surface, and 5 mu m from the outermost layer of fibers, the stresses measured with x-rays are comparable to the bulk stresses as measured with neutron diffraction. Neutron diffraction line broadening measurements show that in directions perpendicular to the fibers more broadening exists than in directions parallel to the fiber axes. This can be explained by a more nonuniform distribution of the hoop and radial stresses around the fibers in comparison with that of the axial stress, and by the variation of angles between the hoop and radial stresses and the considered lattice planes.