Abstract
Mechanisms of longitudinal creep deformation and damage were studied in an eight-ply unidirectional-reinforced SCS-6/Ti-6Al-4V composite. The composite was creep tested in air under constant tensile load at temperatures from 427 °C to 650 °C and stresses from 621 to 1380 MPa.In situ acoustic emission (AE) monitoring and post-test metallographic evaluation were used to study fiber fracture and damage during creep. At low creep stresses, creep rates continuously decreased to near-zero values. This was attributed to a mechanism of matrix relaxation and the time-dependent redistribution of load from the ductile matrix to the elastic fibers. At higher stresses, progressive fiber overload occurred during creep loading. In this case, the composite exhibited a stage of decreasing creep rate (due primarily to matrix relaxation), followed by a secondary stage of nearly constant creep rate due to fiber fracture. The results indicate that interfacial oxidation damage and inefficient load transfer at elevated temperatures significantly decreased the capability of broken fibers to carry load. As a result, additional time-dependent stress redistribution occurred in the composite, which was responsible for the secondary creep stage.
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J.A. DiCarlo:J. Mater. Sci., 1986, vol. 21, pp. 217–24.
J. Beale, E. Lara Curzio, and S.S. Sternstein:Proc. 35th Int. SAMPE Symp., SAMPE, Corvina, CA, 1990, pp. 1193–1204.
M. Khobaib:Proc. American Society for Composites—Sixth Technical Conf., Technomic Publishing Co., Lancaster, PA, 1991, pp. 638–47.
S.W. Schwenker, D. Evans, and D. Eylon: inTitanium ’92 Science and Technology, F.H. Froes and I.L. Caplan, eds., TMS, Warrendale, PA, 1993, vol. 3, pp. 2545–51.
S.W. Schwenker, I. Roman, and D. Eylon: inAdvanced Composites ’93, T. Chandra and A.K. Dhingra, eds., TMS, Warrendale, PA, 1993, pp. 1169–76.
S.W. Schwenker: Ph.D. Thesis, University of Dayton, Dayton, OH, 1994.
S.M. Jeng and J.-M. Yang:Mater. Sci. Eng., 1993, vol. A171, pp. 65–75.
N. Ohno, N. Okamoto, T. Miyake, S. Nishide, and S. Masaki, Jr.:Scripta Metall. Mater., 1994, vol. 31, pp. 1549–54.
N. Ohno, K. Toyoda, N. Okamoto, T. Miyake, and S. Nishide:Trans. ASME, 1994, vol. 116, pp. 208–14.
D.L. McDanels, R.A. Signorelli, and J.W. Weeton: NASA-TN-D-4173, NASA-Lewis Research Center, Cleveland, OH, 1967.
M. Taya: inMetal Matrix Composites: Mechanisms and Properties, R.K. Everett and R.J. Arsenault, eds., Academic Press, Boston, MA, 1991, pp. 189–215.
M. McLean:Compos. Sci. Technol., 1985, vol. 23, pp. 37–52.
M. McLean: inMaterials and Engineering Design: The Next Decade, B.F. Dyson and D.R. Hayhurst, eds., Institute of Metals, London, 1989, pp. 287–94.
S. Goto and M. McLean:Acta Metall. Mater., 1991, vol. 39 (2), pp. 153–64.
R.A. MacKay, P.K. Brindley, and F.H. Froes:JOM, 1991, vol. 43, pp. 23–29.
S.R. Nutt and F.E. Wawner:J. Mater. Sci., 1985, vol. 20, pp. 1953–60.
X.J. Ning and P. Pirouz:J. Mater. Res., 1991, vol. 6, pp. 2234–48.
G.A. Hartman and S.M. Russ: inMetal Matrix Composites: Testing, Analysis, and Failure Modes, W.S. Johnson, ed., ASTM STP 1032, ASTM, Philadelphia, PA, 1989, pp. 43–53.
I. Roman and R. Aharonov:Acta Metall. Mater., 1992, vol. 40, pp. 477–85.
I. Roman, S. Krishnamurthy, and D.B. Miracle: inTitanium ’92 Science and Technology, F.H. Froes and I.L. Caplan, eds., TMS, Warrendale, PA, 1993, vol. 3, pp. 2545–51.
J. Awerbuch and J.G. Backuckas: inMetal Matrix Composites: Testing, Analysis, and Failure Modes, W.S. Johnson, ed., ASTM STP 1032, ASTM, Philadelphia, PA, 1989, pp. 68–99.
R.W. Evans and B. Wilshire:Creep of Metals and Alloys, Institute of Metals, London, 1985.
M.L. Gambone and F.E. Wawner: inIntermetallic Matrix Composites III, J.A. Graves, R.R. Bowman, and J.J. Lewandowski, eds., MRS, Pittsburgh, PA, 1994, vol. 350, pp. 111–18.
M.L. Gambone and S.W. Schwenker: Wright Laboratory, Materials Directorate, Wright-Patterson AFB, OH, unpublished research, 1994.
S.M. Pickard, D.B. Miracle, B.S. Majumdar, K.L. Kendig, L. Rothenflue, and D. Coker:Acta Metall. Mater., 1995, vol. 43, pp. 3105–12.
B.S. Majumdar and G.M. Newaz:Phil. Mag., 1992, vol. 66, pp. 187–212.
D. Coker and N.E. Ashbaugh:Elastic-Plastic Finite Difference Analysis of Unidirectional Composites Subjected to Thermomechanical Cyclic Loading, WL-TR-93-4043, Wright Laboratory, Wright-Patterson AFB, OH, 1992.
M.J. Iremonger and W.G. Wood:J. Strain Analysis, 1967, vol. 2 (3), pp. 239–45.
Z.-Z. Du and R.M. McMeeking:J. Mech. Phys. Solids, 1995, vol. 43, pp. 701–26.
W.A. Curtin:J. Am. Ceram. Soc., 1991, vol. 74, pp. 2837–45.
C. Weber, Z.-Z. Du, and F.W. Zok:Acta Metall. Mater, 1996, vol. 44 (2), pp. 683–95.
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Schwenker, S.W., Eylon, D. Creep deformation and damage in a continuous fiber-reinforced Ti-6Al-4V composite. Metall Mater Trans A 27, 4193–4204 (1996). https://doi.org/10.1007/BF02595667
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DOI: https://doi.org/10.1007/BF02595667