Experimental study of heat conductivity of carbon composite implants with calcium phosphate based coatings

Data on the experimental measuring the thermal conductivity of carbon-carbon composite used as bone substitute and filling medical implant material are presented. The heat transfer through the substrate has a defining impact on the properties of a calcium phosphate coating formed by powder spraying onto the implant surface. The correct choice of deposition modes, taking into account the thermal properties of the processed materials, makes it possible to form coatings with controlled crystallinity and to avoid the growth of unwanted phases. Because of a complex structure of the grafts and the interface “graft/coating” an analytical estimation of their heat properties is difficult. The thermal conductivity of both an uncoated carbon substrate and a substrate with calcium phosphate coating (based on HAp films) of 100 µm thick was studied experimentally. A steady-state heating in vacuum condition was used as an experimental technique. A thermal conductivity of the carbon-carbon composite was ≈9.729±0.623 W/(m·K) while the effective heat conductivity of the calcium phosphate coating did not exceed ≈0.054±0.009 W/(m·K).