Yukimi Tanaka, Yutaka Seino, Koichiro Hattori
Comparison of Experimental and Theoretical Indentation Moduli of Anisotropic Single Crystals

Nanoindentation is a useful method for measuring elastic modulus. However, the elastic modulus of anisotropic single crystal measured by nanoindentation is often different from theoretical value calculated by elastic constants. Hence, we investigated the cause of the problem above by measuring indentation moduli of 4H-SiC, sapphire and quartz with a Berkovich and a spherical indenter. Consequently, the experimental elastic moduli were 5-15 percent higher than the theoretical value regardless of indenter shape and calculation method. The difference between theoretical and experimental modulus suggests to be not concerned with underestimation of contact area due to plastic deformation such as pile-up.

Takashi Yamamoto, Masayuki Yamamoto, Mizuki Watanabe, Kensuke Miyahara
Study on Similarity Low of Hardness Using Small Ball Rebound Test, eNM

We investigated the law of similarity for hardness with respect to a newly-developed small ball rebound hardness test method. In the case of a spherical indenter hardness test such as that used for Brinell hardness, only if d/D were a constant, where D is the diameter of the indentation and is the diameter of the spherical indenter, would the indentations and the deformation regions caused by spherical indenters of different sizes have similar shapes, and therefore allow the same hardness values to be obtained. Using hardness blocks of 200 to 900 HV made of eutectoid carbon steel as specimens, as the measure of hardness we investigated the coefficients of restitution for 5, 3, and 2 mm alumina ceramic ball indenters with an impact velocity of 10 m/s. The test results were that the coefficients of restitution agreed well with the values of d/D for spherical indenters of different sizes, so we believe that this test method is a rebound hardness test method that satisfies the law of similarity for hardness, as is true for Vickers hardness.

Dongmei Ren, Yu Wan, Zhenyu Zhu, Xiaoyan Duan
An Area Function Measurement Method Based on Indenter Geometry for Small-Depth Nanoindentation

The measurement methods of area function that are commonly used in nanoindentation are summarized and analyzed. An area function determination method based on the geometry of indenter tip for very small indentation depth is proposed. It combines the advantages of the area function measurement method based on measurement of standard sample and that based on indenter geometry. Experiments have been carried out to examine the effect of the area function. It is shown that this area function measurement method can improve the measurement accuracy of indentation hardness and reduced modulus when the indentation depth is very small.

C. Frehner, J. Meier
New Generation of UCI Probes with Accurate Force Detection and Their Applications and Practical Benefits

In this paper a new generation of UCI probes will be introduced. In contrast to regular UCI probes which use a spring in combination with an end switch to trigger the measurement, these probes are equipped with an internal force sensor to make them adjustable to different test loads. As this technology allows to monitor the applied test load constantly, it brings additional benefits to the user.
These possibilities will be described and explained in this paper. The advantages shall be presented and practical examples shall be given where they can be used. Furthermore, they will be supported with measurements on real test samples to quantify the real upside over traditional probes.
To conclude this paper an outlook will be given with additional options to improve the UCI measurement principle further and to show in which direction future developments will go.

Alessandro Schiavi, Claudio Origlia, Alessandro Germak, Giulio Barbato, Giovanni Maizza,Gianfranco Genta, Roberto Cagliero, Gianluca Coppola
Measurement of Macro-Scale Indentation Modulus Using the Primary Hardness Standard Machines at INRIM

In this paper it is described the experimental procedure and the statistical method for the measurement of indentation modulus by using the primary hardness standard machine at INRIM, in the macro-scale range. Indentation modulus is calculated on the basis of Doerner-Nix linear model and from accurate measurements of indentation load, displacement, contact stiffness and Vickers hardness impression imaging. Load is provided by dead-weight masses and displacement is measured by a laser-interferometric system, perpendicular with respect to the Vickers pyramid vertex. The geometrical dimension of the Diamond Pyramid Hardness (DPH) impression is measured by means of a micro-mechanical system and optical microscopy imaging technique. Applied force and indentation depth are measured simultaneously, 16 Hz of sampling rate, and the resulting indentation curve is obtained. Preliminary tests are performed on metals and alloys samples. Considerations and comments on the accuracy of the proposed method and analysis are discussed.