Autor(es): Nunes, D. ; Livramento, Vanessa ; Fernandes, H. ; Silva, C. ; Shohoji, Nobumitsu ; Correia, J.B. ; Carvalho, Patricia Almeida
Data: 2013
Identificador Persistente: http://hdl.handle.net/10400.9/2414
Origem: Repositório do LNEG
Assunto(s): Composites; Extrusion; High energy milling; Microdiamond; Nanodiamond
Nanostructured copper-diamond composites can be tailored for thermal management applications at high temperature. A novel approach based on multiscale diamond dispersions is proposed for the production of this type of materials: a Cu-nDiamond composite produced by high-energy milling is used as a nanostructured matrix for further dispersion of micrometer sized diamond. The former offers strength and microstructural thermal stability while the latter provides high thermal conductivity. A series of Cu-nDiamond mixtures have been milled to define the minimum nanodiamond fraction suitable for matrix refinement and thermal stabilization. A refined matrix with homogenously dispersed nanoparticles could be obtained with 4 at.% nanodiamond for posterior mixture with ƒÝDiamond and subsequent consolidation. In order to define optimal processing parameters, consolidation by hot extrusion has been carried out for a Cu-nDiamond composite and, in parallel, for a mixture of pure copper and ÝDiamond. The materials produced were characterized by X-ray diffraction, scanning and transmission electron microscopy and microhardness measurements.
