Hot-pressed hydroxylapatite/monoclinic zirconia composites with improved mechanical properties

Evis Z., Doremus R. H.

JOURNAL OF MATERIALS SCIENCE, vol.42, no.7, pp.2426-2431, 2007 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 42 Issue: 7
  • Publication Date: 2007
  • Doi Number: 10.1007/s10853-006-1299-6
  • Journal Name: JOURNAL OF MATERIALS SCIENCE
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.2426-2431
  • Middle East Technical University Affiliated: Yes

Abstract

Composites of hydroxylapatite (HA) and monoclinic zirconia were hot-pressed at 1100 degrees C and 1200 degrees C under vacuum to study the phase transformations and the mechanical properties. X-ray diffraction results showed a higher phase transformation from monoclinic-ZrO2 to tetragonal-ZrO2 when the sintering temperature increased from 1100 degrees C to 1200 degrees C. HA decomposed faster when the amount of ZrO2 in the composites increased. Moreover, small amount of alpha-TCP and CaZrO3 was observed in the composites hot-pressed at 1200 degrees C. Hot-pressing at 1100 degrees C resulted in better mechanical properties than the hot-pressing at 1200 degrees C because of less reaction between HA and zirconia at 1100 degrees C. 40 wt% monoclinic zirconia and HA composite hot-pressed at 1100 degrees C resulted in promising mechanical properties which are 6.5 GPa of Vickers mu-hardness, 2.23 MPa root m of fracture toughness, and 66 MPa of diametral strength.