Photoacoustic determination of thermal conductivity of aluminum nanopowders

Over the last years, photoacoustic spectroscopy (PA) has become a powerful technique to characterize materials. In this paper, the well-known photoacoustic effect (PE) is presented as an effective non destructive method to estimate thermal properties of aluminum nanosized powders prepared with a transient plasma process by wire electrical explosion (WEE). Aluminum nanopowders are very attractive to be used as constituents of energetic materials. Thermal properties, such as thermal conductivity, are important for the study of ignition behavior of aluminum nanopowders. For this work, graphite bars were used as reference material. The experiments showed that nanosized aluminum revealed the same behavior as that of graphite at photoacoustic measurements (similar values of the signal amplitude at various frequencies). It allowed us to assume that both materials have the same thermal diffusivity length.