Mechanical Properties of 2Y-TZP Fabricated from Detonation Synthesized Powder

Frank Kern,Andrea Gommeringer

doi:10.3390/ceramics3040037

Abstract

Yttria stabilized zirconia (Y-TZP) is frequently used in dental and engineering applications due to its high strength and fracture resistance. In this study, 2Y-TZP samples were manufactured from commercially available powder produced by detonation synthesis. Tests of the mechanical properties exhibited an unusual combination of both very high strength and toughness. The materials show a very weak correlation between toughness and grain size. The transformability, measurable by XRD, cannot explain the high toughness. Fractographic analysis revealed a broad transformation affected zone with secondary cracks and shear bands on the tensile side of bending bars which can be made responsible for the high toughness and non-linear stress–strain curves.

Highlights

Yttria stabilized zirconia ceramics are commodities used in various applications such as biomedical, mechanical, sensors, solid oxide fuel cells, and thermal barrier coatings [1,2,3,4,5]
This study aims at finding the clue to this uncommon combination of properties by carrying out a detailed mechanical microstructure and phase composition analysis
As shown above the threshold toughness of ≈4.5 MPa m determined by stable indentation crack growth in bending (SIGB) is only slightly higher than for other Y-TZP materials made from coprecipitated powders [42]

Summary

Introduction

Yttria stabilized zirconia ceramics are commodities used in various applications such as biomedical, mechanical, sensors, solid oxide fuel cells, and thermal barrier coatings [1,2,3,4,5]. For structural applications zirconia materials stabilized in the tetragonal phase by addition of 2–3 mol % Y2 O3 (2-3Y-TZP) are relevant. These materials show a combination of high strength and fracture resistance due to transformation toughening, a stress induced martensitic transformation from metastable tetragonal to stable monoclinic phase. The phase transition comes along with a volume expansion ε = 4–5%.

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Conclusion