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The impulse acoustic microscopy method was applied to observe the bulk microstructure and to measure sonic velocities and elastic moduli in the carbon nanocomposite specimens prepared by a traditional method and with the use of a vacuum mixer. It is shown that carbon nanoparticles tend to cluster and form micron-sized aggregates. The impulse acoustic microscopy technique makes it possible to visualize a nonuniform distribution of carbon nanofillers over the specimen bulk. Both nanotube and nanoplatelets conglomerates are visible most likely due to the air containing. Results of the elastic measurements demonstrate homogeneity of elastic properties over the material bulk and a weak dependence of sonic velocities and elastic moduli on the filler content. Reduction of the air content and enhancement of elastic properties are observed when increasing the nanofiller content and employing the vacuum mixing technology in nanocomposite fabrication., INTRODUCTION Essential changes in material properties of nanocomposites result from formation of extensive networks of contacting nanoparticles with high values of the aspect ratio--nanotubes, nanoplatelets, nanoflakes, and so forth. A [...]

Non-destructive inspection of carbon fiber-reinforced (CFR) composites applied to aerospace industry attracts wide attention. In this article, high frequency (50-100 MHz) focused ultrasound has been applied to study defects and destruction processes in the bulk microstructure of the CFR material and constructions under the mechanical loading. It has been shown that the impulse acoustic microscopy provides detecting areas of structural failures and adhesion losses at the millimeter and micron level. Behavior of the CFR laminate structure fabricated by prepreg or infusion technology has been investigated under the tensile and impact loading., INTRODUCTION Application of fiber-reinforced polymers (FRP) is extensive in aviation industry due to their excellent strength-to-weight ratio. The sufficient strength is achieved by reinforcement of polymer matrix by regular packaging [...]