Dynamic mechanical behavior of nickel-based superalloy metal rubber

The work describes the manufacturing and dynamic characterization of nickel wire-based metal rubber (MR) solids. The storage modulus and the loss factor of the nickel MR samples are measured over a frequency range between 0.1 Hz and 200 Hz, and at different levels of dynamic force and strain using a dynamic mechanical analyzer (DMA) technique. A sensitivity analysis about the effect of different static and dynamic testing parameters is initially carried out to identify suitable testing protocols for this metal porous material. DMA testing is then carried out over three different batches of samples (5 specimens each) with variable relative densities to identify the correlation between storage modulus and loss factors with frequency and dynamic force and strain levels. The results are discussed using a mechanical theoretical model relating the mechanical properties of MR solids to the contact states of the wire composing the microstructure. A comparison with analogous results obtained from cyclic tests at 1 Hz from a conventional tensile machine is also performed. The results from this benchmark highlight the necessity to use dynamic-based testing protocols to efficiently implement nickel-based metal rubber for vibration damping and energy absorption designs and applications.