The Role of Nb₂Zr₆O₁₇ Phase on the Hardness and Fracture Toughness of ZTA/Nb₂O₅ by Cold Isostatic Pressing

Abstract:

The microstructure and mechanical properties of zirconia toughened alumina (ZTA) ceramic added with niobia (Nb₂O₅) through cold isostatic pressing (CIP) method was investigated. The amount of Nb₂O₅ is varied from 0 wt.% to 7 wt.%. The phase composition of the sintered bodies was analyzed with an x-ray diffractometer, while their microstructure was observed with a scanning electron microscope. It is found that up to 3 wt.% of Nb₂O₅ addition, the secondary phase of Nb₂Zr₆O₁₇ presence as square shape particles confirm by SEM and EDX. The addition of 3 wt.% showed the highest Vickers hardness value with 1600HV. It was observed that, further addition of Nb₂O₅ (> 3 wt.% ) deteriorates the Vickers hardness of ZTA. While the fracture toughness value increased at 3 wt.% until 5 wt.% of Nb₂O₅ addition (6.71 MPa · √m and 6.80 MPa · √m respectively). It was also found that the value for bulk density increased and porosity decreased with the increasing of Nb₂O₅ addition.

• Periodical: Materials Science Forum (Volume 888)
• Pages: 126-130
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.888.126
• Online since: March 2017
• Authors: Nurul Khairunnisa Su, Muhammad Fadhlullah Al-Amin ABDUL RAZAK, Banjuraizah Johar*, Muhammad Asri Idris, Zainal Arifin Ahmad
• Keywords: Cold Isostatic Pressing (CIP), Fracture Toughness, Hardness

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