Thermal conductivity measurements have been made on composites of unal
loyed Ti reinforced with short fibre SiC, particulate SiC and particul
ate TiB2, and Ti-6Al-4V reinforced with long fibre SiC. Measurements w
ere also made on the unreinforced matrices and on the reinforcements t
hemselves. The results have been compared with predictions from the Ha
sselman and Johnson model for spherical and long fibre composites and
from the Eshelby model for ellipsoids of any aspect ratio. It is shown
that, while an enhancement of the thermal conductivity is expected to
arise from the presence of both types of particulate, this effect is
in fact produced only with the TiB2 reinforcement. This is explained i
n terms of the large thermal resistance of the SiC/Ti interface, which
is in turn related to the nature of the reaction layer formed there d
uring processing. The transverse conductivity of the Ti-6Al-4V reinfor
ced with long SiC fibres was also impaired by the high thermal resista
nce of the interface, but in this case the effect was less significant
because of the larger diameter of the reinforcement, which reduces th
e frequency with which transport of heat across an interface must occu
r. Finally, similar characteristics were exhibited by the short SiC fi
bre/Ti composite, except that the axial conductivity was rather lower
than expected. This effect is attributed to matrix porosity localized
at the fibre ends.