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The response of amorphous steels to shock wave compression has been explored for the first time. Further, the effect of partial devitrification on the shock response of bulk metallic glasses is examined by conducting experiments on two iron-based in situ metallic glass matrix composites, containing varying amounts of crystalline precipitates, both with initial composition Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4. The samples, designated SAM2X5-600 and SAM2X5-630, are X-ray amorphous and partially crystalline, respectively, due to differences in sintering parameters during sample preparation. Shock response is determined by making velocity measurements using interferometry techniques at the rear free surface of the samples, which have been subjected to impact from a high-velocity projectile launched from a powder gun. Experiments have yielded results indicating a Hugoniot Elastic Limit (HEL) to be 8.58 ± 0.53 GPa for SAM2X5-600 and 11.76 ± 1.26 GPa for SAM2X5-630. The latter HEL result is higher than elastic limits for any BMG reported in the literature thus far. SAM2X5-600 catastrophically loses post-yield strength whereas SAM2X5-630, while showing some strain-softening, retains strength beyond the HEL. The presence of crystallinity within the amorphous matrix is thus seen to significantly aid in strengthening the material as well as preserving material strength beyond yielding.

An experimental study of shock wave profiles in particulate composites of various compositions is undertaken to determine how shock width and rise times depend on the mean particulate size. The composites under examination serve as a model for concrete or polymer bonded explosives, based upon the impedance mismatch between the relatively stiff particulates and compliant matrix. Polymethyl Methacrylate (PMMA) and glass spheres ranging in size from 100μm to 1000μm are used in concentrations of 30% and 40% glass by volume for experiments with a single bead size, and up to 50% glass by volume for multi-mode particle size distributions. A linear change in shock wave rise time is observed as a function of mean particulate diameter.

The shock compression response of particulate heterogeneous solids was investigated using normal plate impact experiments and numerical simulations. A model composite system of silica glass spheres embedded in a matrix of thermoplastic polymer, polymethyl methacrylate, was developed to mimic the impedance mismatch of structural and energetic heterogeneous materials. Shock wave profiles were measured at multiple points on the rear surface of the composite specimens to characterize shock dispersion and spatial heterogeneity in material response due to the random distribution of particles. Composites with single mode as well as bimodal bead diameter distributions were subjected to plate impact loading at ∼1000 m/s resulting in an average shock stress of ∼4 GPa. Shock rise times were measured for composites of 30% and 40% glass by volume, with spherical particles of diameters in the range of 100-1000 μm. In the case of single mode composites, the shock wave rise times were observed to scale linearly with particle diameter divided by the bulk shock wave speed. The addition of a second bead size to a base size in a 30% glass by volume composite mix resulted in significant increases in shock rise time. Numerical simulations were used to develop insights into scattering and the development of shock structure in particulate composites. Shock disruption mechanisms due to particles and matrix/interface damage effects are discussed.

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