Papers by Author: Yan Liu

Abstract: CSCNT is a new type carbon nanotube, which has better physical and mechanical properties than the traditional materials. In this study, the effect of the dispersion and concentration of cup-stacked carbon nanotubes on mechanical properties of the CSCNTs/epoxy nanocomposites were investigated. The epoxy resin system used in this study was a two component (resin and harder) Prime 20. The CSCNTs were dispersed into the Prime 20 by ultrasonic agitation and mechanical mixing together. And the morphologies of the fracture surface of CSCNTs/Prime 20 nanocomposites were observed by scanning electron microscope (SEM); damping behaviors of the nanocomposites were studied by DMA at frequency domain.

Abstract: The metal and nano-ceramic nanocomposite coatings were prepared on gray cast iron surface by electrodepositon. The nickel and cobalt were used as metal matrix of coating, and the nano-Al2O3 was chosen as second-phase particulates, which had good chemical stability, high microhardness and good wear resistance. The morphology of composite coatings was flatter and microstructure was denser than pure nickel and cobalt coatings. The composite coatings were fabricated by different dispersion methods such as high speed mechanical stir, ultrasonic vibration and ultrasonic vibration together with mechanical stir. The result indicated the nano-Al2O3/Ni+Co composite coating with fine and compact microstructure are obtained compared with pure Ni-Co coating. The nanoparticles were dispersion evenly when dispersion style was ultrasonic vibration together with mechanical stir according to composite coatings SEM images of different dispersion style. The concentration of nanoparticulates reached a maximum value when the dispersion style was ultrasonic vibration together with mechanical stir, at the same time the mechanical property such as microhardness reached a maximum value also. The reason was that nano-Al2O3 caused dispersive strengthening and grain refining.

Abstract: Carbon nanotubes have better physical and mechanical behaviors than the traditional materials, in this study cups-stacked carbon nanotubes (CSCNTs) were filled into epoxy nancomposites to fabricate CSCNTs/epoxy nanocomposites. RTM6 was used by epoxy resin system. The cups-stacked carbon nanotubes (CSCNTs) were dispersed into the RTM6 matrix. In this study, damping properties of the CSCNTs/RTM6 were measured; effect of different weight percentages of the CSCNTs was investigated. And the morphologies of fracture surface of CSCNTs/epoxy nanocomposites were observed by scanning electron microscope (SEM); damping behaviors of the nanocomposites were studied by DMA tester at frequency domain.