Logo image
Elastic and Mechanical Properties of Polycrystalline Transparent Yttria as Determined by Indentation Techniques
Journal article

Elastic and Mechanical Properties of Polycrystalline Transparent Yttria as Determined by Indentation Techniques

Ismail C. Albayrak, Sandip Basu, Aaron Sakulich, Ori Yeheskel and Michel W. Barsoum
Journal of the American Ceramic Society, v 93(7), pp 2028-2034
01 Jul 2010

Abstract

Materials Science Materials Science, Ceramics Science & Technology Technology
The Young's modulus (E) and nanoindentation (NI) stress-strain curves of fully dense, transparent yttria were determined using a nano-indenter capable of continually measuring the stiffness (S). Two hemispherical indenters with radii of 1.4 and 5 mu m were used, in addition to a Berkovich tip. The E values-calculated from the S vs. a (contact radius) curves obtained with both spherical indenters (158-171 GPa) were approximate to 5% lower than the 176 GPa dynamic modulus measured on the same sample using ultrasound. Depending on range of penetration depths, the Berkovich modulus was approximate to 1%-5% higher than the dynamic modulus. When the NI load-displacement curves were converted to NI stress-strain curves, the yield point obtained was 7 +/- 1 GPa. This value was approximate to 20% and approximate to 33% lower than the Vickers and Berkovich hardness values measured on the same sample, respectively. The Vickers microhardness values (8.8 +/- 0.2 GPa) and the fracture toughness extracted from the latter (1.5 +/- 0.3 MPa center dot m1/2) are in good agreement with published results on samples with comparable microstructures. The strain hardening rates were almost identical for both tips; no tip size effect was observed. Based on this work, we conclude that S vs. a plots are a powerful, and relatively simple, technique to measure the Young's moduli of polycrystalline ceramics and other hard solids. The fact that one also obtains NI stress--strain curves is a distinct advantage over the more commonly used Berkovich tip.

Metrics

7 Record Views
37 citations in Scopus

Details

InCites Highlights

Data related to this publication, from InCites Benchmarking & Analytics tool:

Collaboration types
Domestic collaboration
Web of Science research areas
Materials Science, Ceramics
Logo image