Sputter deposition and analysis of thin film Nitinol/Terfenol-D multilaminate for vibration damping

Nitinol/silicon laminates and Nitinol/Terfenol-D/nickel laminates were sputter deposited and characterized using x-ray diffraction (XRD), wavelength dispersive spectrometry (WDS), and a SQUID (superconducting quantum interference device). Dynamic testing showed substantial damping (tanδ) measurable in each laminate. An analytical model of a heterogeneous layered thin film damping material was also developed. Parametric studies with the analytical model illustrate the effect of combining Terfenol-D and Nitinol to create a broadband damping laminate with relatively constant tanδ for strain values between 0.05% and 1%. The model also illustrates the importance of relative stiffness on the damping of multilayer laminates, i.e. relatively high stiffness damping materials such as Terfenol-D and Nitinol may be superior to lower stiffness visco-elastics