Internal friction associated with the melting of Pb nanoparticles in an Al matrix

Pb nanoparticles embedded in an Al matrix were prepared by ball milling and the internal friction behavior associated with the melting of Pb nanoparticles was studied by means of dynamic mechanical analyzer. The height H of internal friction peak was found to be dependent on the frequencies and heating rates, which indicates a first-order phase transition of Pb melting. The internal friction behavior of Pb nanoparticles is discussed with respect to the surface melting.