Internal friction in a Ni-Ti-based glassy-crystal alloy

Dynamic mechanical behavior of the Ni₄₀Cu₁₀Ti ₃₃Zr₁₇ alloy containing higherature cubic and glassy phases was studied in pseudo-elastic mode at relatively small deformations. Amplitude dependent internal friction was measured by increasing the maximal strain amplitude e0 step by step. Two types of tests were applied: a simple test with increase in the amplitude of strain (loading) within each step of loading and a hysteresis loop measurement test. At least three hysteresis loops 'loading-unloading' we measured at each step, and the maximal amplitude was increased at each subsequent step. The results indicate that martensitic transformation in this composite alloy starts in a pseudo-elastic deformation mode and contributes to the internal friction observed in the studied alloy.