Practical and fundamental studies of nanocrystalline composite thin films

Nanocrystalline composite films of Ag-Mo and Ag-Ni have been made by a co-deposition technique in UHV. The structure and composition have been studied by x-ray diffraction (XRD), transmission electron microscopy (TEM), and electron probe microanalysis (EPMA). For practical applications, the friction coefficient and wear rate were measured using a pin-on-plate machine for Ag-Mo composites deposited on steel. For fundamental studies, the hardness of the Ag-Ni composites deposited on oxidized Si wafers was measured using a nanoindenter. Experiments show that (1) reduction of friction and wear rate can be achieved using these nanocomposite coatings and (2) the hardness of the nanocomposites depends on the grain size. As the grain size of the Ag decreases from 100 to 10 nm, the hardness increases about 4 times.