2002 Volume 43 Issue 5 Pages 802-808
Phase transformation behavior, the shape memory characteristics and the superelasticity of Ti–Ni–Cu–Mo alloys have been investigated by means of electrical resistivity measurements, X-ray diffraction, thermal cycling tests under constant load and tensile tests. A fully annealed Ti–44.7Ni–5Cu–0.3Mo alloy transformed in two-stage, i.e., the B2-B19-B19′ on cooling and the B19′-B19-B2 on heating. Fully annealed Ti–39.7Ni–10Cu–0.3Mo, Ti–34.7Ni–15Cu–0.3Mo and Ti–29.7Ni–20Cu–0.3Mo alloys transformed in one-stage on, i.e., from the B2 to the B19 on cooling and from the B19 to B2 on heating. The maximum recoverable elongation deceased from 6.0 to 2.4% with increasing Cu-content from 5 to 20 at%. Transformation hysteresis associated with the B2-B19 transformation decreased from 11 to 5 K with increasing Cu-content from 5 to 20 at%. Substitution of Mo for Ni in Ti–Ni–Cu alloys improved the superelasticity.
