Mechanical characterization for beta-Sn single crystals using nanoindentation tests


Sahin O., Uzun O., Koelemen U. , UÇAR N.

MATERIALS CHARACTERIZATION, vol.59, no.4, pp.427-434, 2008 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 59 Issue: 4
  • Publication Date: 2008
  • Doi Number: 10.1016/j.matchar.2007.02.016
  • Title of Journal : MATERIALS CHARACTERIZATION
  • Page Numbers: pp.427-434
  • Keywords: nanoindentation test, nanohardness, beta-Sn single crystal, indentation size effect, pop-in effect, MICROHARDNESS ANISOTROPY, BASAL-PLANE, INDENTATION, HARDNESS, DEFORMATION, YIELD

Abstract

Depth-sensing nanoindentation tests were made on beta-Sn single crystals having different growth directions. The indentation load-displacement curves of the samples were obtained under different peak loads ranging from 10 to 50 mN. The most commonly used Oliver-Pharr method was used to analyze the unloading segments of these curves. it was found that the dynamic nanohardness (H-d) and reduced elastic modulus (E-r) exhibited significant peak load dependence. The observed size dependence of the H-d was rationalized using classical Meyer's law, Proportional Specimen Resistance (PSR) and the Modified Proportional Specimen Resistance (MPSR) model. Reduced elastic modulus-indentation test load curves exhibited distinct transition to a plateau of constant E-r. It can be concluded that the transition in such curves correspond to the intrinsic E-r value of the examined materials. The examined single crystals also exhibit pop-in phenomenon attributed to the onset of dislocation nucleation activity underneath the indenter. (c) 2007 Elsevier Inc. All rights reserved.