Sintering Behaviour and Properties of Flyash-Doped Zirconia

Abstract:

The effect of flyash (FA) additions of 0.05 wt% to 1 wt% on yttria-stabilized tetragonal zirconia polycrystals (Y-TZP), sintered in air at temperatures ranging from 1250°C to 1500°C, was examined. The bulk density, Young’s modulus, Vickers hardness and fracture toughness for each addition were determined while ageing behaviour were observed by subjecting them to superheated steam at 180°C/10 bar in an autoclave for 24 hours. Additions of FA, particularly of 0.05 wt% and 0.1 wt%, were found to be beneficial in aiding densification and increasing Young’s modulus beyond 200 GPa for sintering temperatures up to 1350°C. A common trend was observed for the Vickers hardness of all additions including undoped; hardness continues to rise from 1250°C and peaked at 1350°C before gradually decreasing as the sintering temperature increases further. No pronounced effect of flyash was seen on the fracture toughness of all samples. The ageing resistance of Y-TZP improved with addition of FA resulting in relatively lower amount of ageing-induced tetragonal to monoclinic phase transformation exhibited by doped samples compared to the undoped.

• Periodical: Materials Science Forum (Volume 894)
• Pages: 85-88
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.894.85
• Online since: March 2017
• Authors: Singh Ramesh*, Wai Jin Kelvin Chew, H.C. Alexender Chee, C.Y. Tan
• Keywords: Ageing, Flyash, Mechanical Properties, Y-TZP, Zirconia

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