Dynamic hardness and elastic modulus calculation of porous SiAlON ceramics using depth-sensing indentation technique


Sahin O., Uzun O., Sopicka-Lizer M., Gocmez H., Kolemen U.

JOURNAL OF THE EUROPEAN CERAMIC SOCIETY, vol.28, no.6, pp.1235-1242, 2008 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 28 Issue: 6
  • Publication Date: 2008
  • Doi Number: 10.1016/j.jeurceramsoc.2007.09.052
  • Title of Journal : JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
  • Page Numbers: pp.1235-1242
  • Keywords: mechanical properties, hardness, SiAlON, depth-sensing indentation technique, indentation, LOAD, MICROHARDNESS, SUPERCONDUCTORS, MICROSTRUCTURE

Abstract

Interest in characterizing the mechanical properties of porous materials at micro-/nanometer scales has increased due to recent development of micro-/nanosystems. Depth-sensing indentation (DSI) systems, also referred to as nanoindentation, are strong tools for performing indentation measurements. The load-displacement curves of SiAlON-based porous ceramics were measured under different peak load (200-1800 mN). The most commonly used Oliver-Pharr method was used to analyze the unloading segments of these curves. The experimental results revealed that the dynamic hardness (H-d) and reduced elastic modulus (E,) exhibit peak-load dependence, i.e., indentation size effect (ISE). Such peak-load dependence requires calculation of the load-independent hardness (H-LI) and elastic modulus (E,). The experimental hardness data were analyzed using Meyer's law, Hays-Kendall's model, the proportional specimen resistance (PSR) model, and the modified PSR (MPSR) model. As a result, the modified PSR model is found to be the most effective one for Hd determination of these SiAlON-ceramics. (c) 2007 Elsevier Ltd. All rights reserved.