The effect of La2O3 on the microstructure and room temperature mechanical properties of t-ZrO2


Nilufer I. B. , GOKCE H. , MUHAFFEL F. , Öveçoğlu M. L. , Çimenoğlu H.

CERAMICS INTERNATIONAL, cilt.42, ss.9443-9447, 2016 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 42 Konu: 8
  • Basım Tarihi: 2016
  • Doi Numarası: 10.1016/j.ceramint.2016.02.180
  • Dergi Adı: CERAMICS INTERNATIONAL
  • Sayfa Sayıları: ss.9443-9447

Özet

Structural and mechanical properties of La2O3 added (up to 5 wt%) t-ZrO2 compacts were examined with the aim of optimizing hardness and fracture toughness for room temperature applications. Structural examinations were performed using an X-ray diffractometer and a scanning electron microscope. Mechanical properties of the compacts were determined as modulus of elasticity, hardness and fracture toughness by conducting Vickers indentation tests under test loads of 0.5, 1 and 10 kg. Addition of 0.5 wt% La2O3 deteriorated the room temperature stability of t-ZrO2 by forming m-ZrO2 and coarse polygonal grains in the matrix. Higher concentrations (2 and 5 wt% La2O3) caused precipitation of La2Zr2O2 at the grain boundaries, which also accompanied by a reduction in hardness. Fracture toughness increased with increasing La2O3 content of the compact. Finally, an optimum combination between hardness and fracture toughness was obtained for the 0.5 wt% La2O3 containing compact. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.