  Nanodiamond reinforced silver matrix nanocomposites with different
nanodiamond content are produced from pure silver and nanodiamond powders by a
combination of two severe plastic deformation methods, ball-milling and
high-pressure torsion (HPT). The ball milling parameters are varied to improve
the distribution of the nanodiamonds in the powder blends. An optimized
processing route combining both processes has been developed to achieve a
homogenous dispersion of small nanodiamond particles in a nanocrystalline
silver matrix. The microstructure of these nanocomposites was characterized by
scanning and transmission electron microscopy. The mechanical properties were
characterized by microhardness measurements and tensile tests. An increasing
amount of nanodiamonds (up to 5 wt% and 15 vol%, respectively) can raise the
microhardness by up to 70 % and the tensile strength by up to 60 % of the
values achieved in HPT deformed pure silver. The microhardness and tensile
strength is about 5 times higher than microcrystalline pure silver.
