a1 CSM Instruments, Needham, Massachusetts 02494
a2 Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
Instrumented indentation (referred to as nanoindentation at low loads and low depths) has now become established for the single point characterization of hardness and elastic modulus of both bulk and coated materials. This makes it a good technique for measuring mechanical properties of homogeneous materials. However, many composite materials are composed of material phases that cannot be examined in bulk form ex situ (e.g., carbides in a ferrous matrix, calcium silicate hydrates in cements, etc.). The requirement for in situ analysis and characterization of chemically complex phases obviates conventional mechanical testing of large specimens representative of these material components. This paper will focus on new developments in the way that nanoindentation can be used as a two-dimensional mapping tool for examining the properties of constituent phases independently of each other. This approach relies on large arrays of nanoindentations (known as grid indentation) and statistical analysis of the resulting data.
(Received July 30 2008)
(Accepted December 11 2008)
b) Current address: Université Paris-Est, Ecole des Ponts, UR Navier, 77455 Champs-sur-Marne, France