화학공학소재연구정보센터
Inorganic Chemistry, Vol.56, No.18, 10998-11007, 2017
Gadolinium Doping in Zirconia-Toughened Alumina Systems and Their Structural, Mechanical, and Aging Behavior Repercussions
A series of Gd3+ dopings in zirconia-toughened alumina (ZTA) systems were undertaken to explore the resultant structural, morphological, hydrothermal aging, and mechanical behavior and imaging contrast abilities. The results from the characterization techniques demonstrate the significance of Gd3+ in preserving the structural stability of ZTA systems. ZTA undergoes phase degradation with 10 wt % Gd3+ at 1400 degrees C, while the 100 wt % Gd3+ yields GdAlO3 even at 1200 degrees C. Gd3+ doping at the intermediate level preserves the structural stability of ZTA systems until 1400 degrees C. Gd3+ occupies the ZrO2 lattice, and its gradual accumulation induces tetragonal ZrO2 (t-ZrO2) to cubic ZrO2 (c-ZrO2) phase transition. alpha-Al2O3 crystallizes at 1200 degrees C and remains unperturbed except for its reaction with the free Gd3+ ions to yield GdAlO3. Aging studies and mechanical tests signify the impeccable role of Gd3+ in ZTA systems to resist phase degradation. Further, the imaging contrast ability of ZTA systems due to Gd3+ doping is verified from the in vitro magnetic resonance imaging (MRI) tests.