Dynamic mechanical analyzer study on surface melting of indium nanoparticles

In this paper, dynamic mechanical analyzer (DMA) and differential scanning calorimetry (DSC) were used to study the melting behavior of Indium (In) nanoparticles dispersed in an aluminum (Al) matrix made by high energy ball milling method. DMA results show that an internal friction peak appears in the vicinity of the In melting point and there exists a linear relationship between the height of internal friction peaks and the total surface area of the In nanoparticles. In contrast, DSC results demonstrate that the endothermic peaks corresponding to the melting of the In nanoparticles with different surface area are all similar. The mechanism of the internal friction peaks is discussed in detail from the viewpoint of surface melting. The study shows that DMA is an ideal technique for studying surface melting of nanoparticles.