Abstract
The effect of vanadium on the physical properties of Cu-graphite composite was investigated for the first time. There is only one other mention up to now in scientific literature: Cu-V-Gr composites were prepared by the stir casting process. There mechanical properties, coefficient of friction and wear were investigated. In this work, Cu-graphite composite with 36.3 vol.% of copper were prepared by gas pressure infiltration of the mixture of coarse grain graphite powder with and without 1 vol.% of vanadium powder with molten copper. The microstructure of composites was investigated via SEM, TEM, and HRTEM. XRD analysis indicated and HRTEM observation confirmed V₈C₇ carbide present at the Cu-graphite interface and also in copper matrix. At the copper-graphite interface there is a sharp transition between copper and V₈C₇ phase. The diffusion layer at the borders with graphite is around 75 nm thick. The created vanadium carbide improved mechanical, but worsened thermophysical properties of the prepared Cu-graphite composites. Therefore, vanadium addition is not attractive for Cu-graphite composites industrial applications that require good thermophysical properties.

Key words
vanadium, vanadium carbides, copper, graphite, gas pressure infiltration, mechanical properties, physical properties

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