Abstract
A shape-memory alloy, nickel-titanium, has been distributed throughout an aluminum matrix, using powder-metallurgy processing, in the hope of using the shape-memory effect to achieve strengthening and improve the fatigue resistance, as compared to the aluminum matrix. The shape-memory effect was activated by cold rolling the samples at −30°C. Upon reheating to the austenite phase, the Ni-Ti was expected to return to its original shape while embedded in the aluminum matrix. It is thought that this action created residual, internal stresses around each particle, which strengthened the material. The yield and ultimate strengths, and the fatigue lives of the Ni-Ti reinforced aluminum composites, have been improved considerably, as compared to the unreinforced material. The cross-sectional microstructures of the composites, as well as the modes of crack growth, have been examined with a scanning electron microscope (SEM) to identify fatigue and fracture mechanisms.
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For more information, contact P.K. Liaw, the University of Tennessee, Department of Materials Science and Engineering, Knoxville, TN 37996-2200; (865) 974-6356; fax (865) 974-4115; e-mail pliaw@utk.edu.
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Porter, G.A., Liaw, P.K., Tiegs, T.N. et al. Ni-Ti SMA-reinforced Al composites. JOM 52, 52–56 (2000). https://doi.org/10.1007/s11837-000-0084-2
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DOI: https://doi.org/10.1007/s11837-000-0084-2