Fabrication of graphite nanofibers reinforced metal matrix composites by powder metallurgy and their mechanical and physical characteristics

Abstract

Aluminum metal matrix composites reinforced by graphite nanofibers (GNFs) are fabricated by conventional powder metallurgy methods, and their mechanical and physical characteristics are investigated. Mixing conditions are established by microhardness tests and microscopy observations. The GNF-Al composites are consolidated by hot isostatic pressing (HIP); a high density of composites can be achieved. From microhardness and compression tests, the optimal nanofiber content is determined. The physical properties of the GNF-Al composites are measured by thermal and electrical transport tests. The results indicate that the addition of nanofibers improves the thermal conductivity and the electrical resistivity, but the dimensional stability under high temperatures is not improved. This study may provide experimental information in the design and fabrication of functional metal matrix nanocomposites.