Nanocomposite materials consisting of a nanocrystalline Ni matrix with grain size ranging from 23 to 40 nm, and nano-size SiO2 particles with average particle size of 7 nm, have been produced by pulse electrodeposition. Grain size was controlled by peak current density. It was observed that SiO2 particles precipitated within grain interior by the transmission electron microscopy (TEM). Hardness and tensile strength of nanocomposites with a grain size larger than 35 nm was higher than that of nanocrystalline pure Ni possibly as a consequence of Orowan precipitation hardening. However, hardness of Ni-SiO2 nanocomposites with a grain size smaller than 30 nm was the same as that of nanocrystalline pure Ni. It was considered that the SiO2 particles do not contribute to hardening because deformation occurs by a grain-boundary-mediated mechanism such as grain-boundary sliding.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.