Kinetics of the Phase Transformation of Non-HIPed Zirconia Femoral Heads
The kinetics of tetragonal-to-monoclinic phase transformation (t→m transformation) in the earlier generation zirconia femoral heads was evaluated by X-ray diffractometry, laser microscopy and Raman microprobe spectroscopy. From previous results of hip-simulator study, it was confirmed that phase transformation on the surface of zirconia femoral heads had little influence on wear rate of UHMWPE sockets, and in some zirconia femoral heads, only a slight increase in monoclinic fraction was observed during hip-simulator test. In this study, we suggest that the models of phase transformation progress during tests in hip-simulator and aging tests are different based on both laser microscopic and Raman/fluorescence spectroscopic observation. Besides this finding, this study shows that Raman spectroscopy is a useful technique for the evaluation of the kinetics of phase transformation in femoral heads after both in vitro and in vivo environmental exposure.
Xingdong Zhang, Xudong Li, Hongsong Fan, Xuanyong Liu
J. Ikeda et al., "Kinetics of the Phase Transformation of Non-HIPed Zirconia Femoral Heads", Key Engineering Materials, Vols. 330-332, pp. 1203-1206, 2007