Fabrication, Structure And Propertiesof A Doped SnO₂/Cu Nano-Composite

Nano-SnO2powders doped by TiO2were fabricated via a sol-gel technique in thepresent study. Nano-SnO2and Cu powders were mixed homogeneously by ball-millingmethod, followed by the fabrication of SnO2/Cu composite via a powder metallurgy method.The process of Cu-based nano-composite is optimized by the orthogonal experiment. Themicroscopic morphology, phase as well as the basic physical and mechanical properties ofthe composite with different mass fraction have been investigated.The results showed that:1. Microscopic observation of SnO2/Cu nano-composite ball-milled with300r/min and10h indicated that nano-SnO2particles distributed homogeneously in Cu matrix, i.e.agglomeration of nano-SnO2was not obvious, this showed that the effect of the baii-millingis good.2.Orthogonal experiment was used in orde to improve the preparation, and the bestprocess showed that: the mass fraction is0.5%,the pressing pressure is700Mpa, thesintering temperature is950℃and the sintering time is3h.3. Compared with the pure Cu, the decrease of the electrical conductivity of thecomposite is indistinguishable, the hardness has been marked elevated. With increasing ofthe second phase, the density and electrical conductivity of the composite s decrease, whilethe hardness increases.When the content of SnO2is0.3%, the electrical conductivity is45.5MS/m, and the hardness is130HV, the general properties are better.4. Compared with the pure Cu, when the content of SnO2is0.2%,the mechanism ismild abrasive wear, the wear rate decreased. With increasing the content of SnO2, abrasivewear of the composite material is severe. An adhesive wear will also appear when the massfraction of SnO2is1.0%, this lead to wear rate increase. When the load from50N to100N,the wear rate of the composites increases significantly, and the wear mechanism changesinto the serious peeling wear.