Microhardness and elastic properties of nanocrystalline silver

Microhardness and elastic properties of silver nanopowder compacts are measured as a function of annealing temperature in the range 20 degC to 400 degC). The elastic moduli were estimated from measurements of the sound velocity at 5 Mc. A substantial decrease (1 5-20%) of the effective elastic moduli on increasing annealing temperature is observed. A possible explanation of this phenomenon is given