화학공학소재연구정보센터
Materials Chemistry and Physics, Vol.146, No.3, 456-463, 2014
In vitro ageing and wear behaviour of ceria stabilized zirconia toughened alumina (CSZ-TA) bio-ceramic
15-25 wt% zirconia (stabilized with 14 mol% ceria) toughened alumina was synthesized by co-precipitation technique. The synthesized powders were calcined at different temperatures, compacted and conventionally sintered following two steps sintering process. Uniformly distributed submicron sized grains with Vickers' hardness value up to 1730 +/- 6HV20 were achieved after conventional sintering. In order to assess the ageing behaviour, samples were hydrothermally treated (in vitro) at 134 degrees C under 0.2 MPa in presence of simulated body fluid. Rietveld refinement of the X-ray diffraction patterns was carried out to estimate the phase content after calcination, sintering and after different stages of hydrothermal treatment. No significant phase change (only similar to 3%) was observed even after 100 h of hydrothermal treatment. Very few bulged grains (resulted from the tetragonal to monoclinic phase transformation) on the surface and slight decrease in hardness value were observed after hydrothermal treatment. Fretting wear in dry condition was carried out taking ball on flat geometry for 10(5) cycles at different loads before and after hydrothermal treatment. Wear volumes were directly estimated from the surface scanning of the wear scar using profilometer. Transition of wear and its related mechanisms at different loads along with the effect of ageing on wear were discussed. (C) 2014 Elsevier B.V. All rights reserved.