Zirconia-fluorapatite materials produced by HIP

Composites of tetragonal zirconia and fluorapatite were sealed in steel tub es and hot isostatically pressed at 1200 degrees C. The phases formed in th e samples were evaluated by X-ray powder diffraction. When the composites c ontained larger amounts of fluorapatite, the tetragonal zirconia changed gr adually into the cubic phase with decreasing zirconia content. These phase changes occurred due to a transfer of calcium from fluorapatite, which acte d as an additional dopant in zirconia. Small amounts of monoclinic zirconia were also present in all samples. The cell dimension in fluorapatite was c hanged with the composition of the composite. However, decomposition of the fluorapatite was not possible to detect. Vickers hardness and fracture tou ghness were measured and ranged from 5.1 to 10.8 GPa and 0.9-5.5 MPam(1/2), respectively. Microstructures in the composites were studied with scanning electron microscopy. (C) 1999 Elsevier Science Ltd. All rights reserved.