MICROSTRUCTURE AND THERMAL CONDUCTIVITY OF Cu-Cr ALLOYS AND COMPOSITE REINFORCED WITH SHORT HIGH MODULUS CARBON FIBRES

Abstract

Cu-0.2Cr/Granoc composite was prepared by gas pressure infiltration of molten metal alloy into fibre preform in laboratory autoclave. Rod like carbon fibre preform was manufactured from Granoc ® XN-100 high modulus short C fibres with the length of 1 mm via their disintegration and subsequent sedimentation in polyvinylalcohol solution. The fibres were randomly oriented in planes parallel to the x,y directions (in-plane); z-direction is perpendicular to this plane. Thermal diffusivity was measured by means of the flash method and thermal conductivity (TC) was calculated using values of density and specific heat of composite. All measurements were performed at room temperature on disc shaped composite samples with the diameter of 10 mm and the thickness of 5 mm. The TC of composite exhibits anisotropy. TC in z-direction as high as 259.0 Wm -1 K -1 and in-plane as high as 292.0 Wm -1 K -1 were determined. The influence of Cr addition on the TC of four copper alloys (Cu-0.1Cr, Cu-0.2Cr, Cu-0.5Cr and Cu-1Cr) was also determined.