No abstract

Flow agents are widely used in industry, such as the plastics and pharmaceutical industry, to promote the flow of cohesive powders. Few studies of the quantitative effects of the flow agents on the flow of the powder have been reported. In this communication the effect of silica flow agents on the flow of a plastic powder is studied by means of avalanching behaviour. The avalanching behaviour of the powder as modified by the silica flow agents is summarized using descriptive parameters based on the calculation of fractal dimensions in data space and phase-space strange attractors. The structure of the strange attractors are shown to be statistically self-similar and effective descriptors of the change of rheology caused by the presence of the flow agents.

Copper/carbon nanofibre composites containing titanium varying from 0.3wt% to 5wt% were made, and their thermal conductivities measured using the laser flash technique. The measured thermal conductivities were much lower than predicted. The difference between measured and predicted values has often been attributed to limited heat flow across the interface. A study has been made of the composite microstructure using x-ray diffraction, transmission electron microscopy and Raman spectroscopy. It is shown in these materials, that the low composite thermal conductivity arises primarily because the highly graphitic carbon nanofibre structure transforming to amorphous carbon during the fabrication process.

Please cite this article as: Barcena, J., de Cortazar, M.G., Seddon, R., Lloyd, J.C., Torregaray, A., Coleto, J., Effect of the incorporation of interfacial elements on the thermophysical properties of Cu/VGCNFs composites, Composites Science and Technology (2010), doi: 10.1016/j.compscitech.2010 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. and addition of metal nanoparticles (Ti) to Cu matrix deposited by electroless plating. The effect of the incorporation of these metallic elements on the microstructure and thermophysical properties is discussed. B and Ti lead to higher interaction at the Cu/C interface over Ni and Co. ACCEPTED MANUSCRIPTThis allows the reduction of the coefficient of thermal expansion but regarding the thermal conductivity it was not possible to obtain a value higher than that of copper.

This paper examines the effect of anisotropy on the effective composite thermal conductivity, Kc, of metal matrix composites containing carbon-based inclusions. Added effects of thermal interface conductance, hbd, and size have also been considered. It has been found that at high hbd values, the effective thermal conductivity of the composite is limited by inclusion anisotropy. At lower hbd values and smaller inclusion sizes, this effect is greatly diminished due to the more dominant effect of limited heat flow across the interface.