Hot pressed hydroxyapatite-carbon fibre composites

Composite samples were obtained from hydroxyapatite powder and carbon fibre s by hot pressing at 1100 degrees C and 25 MPa for 15 min in argon atmosphe re. Two types of cut carbon fibres produced in a carbonisation process of p olyacrylonitrile (PAN) precursor were used both in non-coated or coated for m. The coatings of calcium phosphate were applied by sol-gel technique. The highly sintered composite with the best strength properties was obtained f rom coated carbon fibres with basic character of the surface. The existence of hydroxyl groups on fibre surface makes possible formation of bonds with the calcium phosphate layer formed as a result of polycondensation followi ng the sol-gel procedure. (C) 2000 Elsevier Science Ltd. All rights reserve d.