Nanoindentation specifications

Where the prime requirement is to obtain absolute values of microhardness in the sense of resistance to plastic deformation, a logical approach is to replace the optical microscope of a microindenter by an electron microscope. A nanoindentation attachment that can be used inside a SEM has been the basis of patents and is commercially available (Bangert Wagendistrel, 1985). In principle, this approach makes it possible to establish a reliable comparison between nanoindentation microhardness values and established scales of microhardness numbers, such as those defined in national standards specifications. It is necessary to overcome the difficulties of imaging small indentations with sufficient contrast, and, at the smallest depths, to correct for the deformation of the required conductive layer of soft metal (Wagendristel et al., 1987). 

Table 2.2. Commercial nanoindentation instrument specifications. (From Pollock, 1992.)...

Experimental techniques most commonly used to probe the plastic properties of thin film materials involve direct tensile loading of either a freestanding film or a film deposited onto a deformable substrate material, microbeam bending of films on substrates, substrate curvature measurement or instrumented depth-sensing nanoindentation. Sahent features of these methods, as well as specific examples of the adaptation of these methods for the study of mechanical properties in thin films, are briefly addressed in the following subsections. 

Ultralow load indentation, also known as nanoindentation, is a widely used tool for measuring the mechanical properties of thin fdms and small volumes of material. The principle is to pushing in a hard material tip called the indenter into the analyzed sample and to measure the curve load-penetration. A modified commercial nanoindenter (Nano indenter XP - MTS) was used to characterize coated materials. The device allows to measure the contact stiffness with superimposing a harmonic oscillation (small amplitude of 3 nm, constant frequency of 32 Hz) to the continuous penetration of the indenter into the sample. This specificity allows one to continually measure the elastic modulus and hardness according to the penetration depth. Loubet et al. demonstrated that reduced Young modulus and hardness for a Berkovich indenter with a dynamic measurement method could be deduced from the following equations [11] ... 

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