The instrumented indentation technique has recently attracted significant research interest because of its various advantages such as nondestructive specimen preparation, easy process, and high spatial resolution. In particular, this technique is a promising alternative to measurement methods of tensile properties and residual stress. We can evaluate tensile properties and residual stress by analyzing the indentation load-depth curve. Tensile properties of materials, primarily yield strength and tensile strength, are obtained by defining representative stress and strain, through the numerous...
Symposium on Recent Advancements in the Theory and Practice of Hardness Measurement · TC5 · 2007 · Download
A new calibration machine according to the requirements given by ISO 14577-3 [1] was described in [2]. The results of the verification are reported in this paper. It is shown that the calibration machine can be used as a national standard for the materials parameter of the instrumented indentation test.
Symposium on Recent Advancements in the Theory and Practice of Hardness Measurement · TC5 · 2007 · Download
The uncertainties of nanoindentation measurement system were evaluated in this paper. A precise electonic balance and an optical interferometric system were respectively utilized to calibrate the force and displacement of nanoindentation measurement system. The uncertainties of reduced modulus and indentation hardness providing from the naoindentaion measurement were respectively obtained.
Symposium on Recent Advancements in the Theory and Practice of Hardness Measurement · TC5 · 2007 · Download
Hardness standard of tungsten single crystal were utilized in order to check stability and reproducibility of nanoindentation testers. The pop-in load and maximum penetration depth were measured and monitored during several hundreds of repeated experiments. One of the tested instruments showed gradual increase of pop-in load and decrease of maximum depth, which indicate the indenter tip was damaged by repeated tests. The both parameters, the pop-in load and the maximum depth, can be used to detect the change of the area function; the pop-in force is more sensitive and should be easy for...
Symposium on Recent Advancements in the Theory and Practice of Hardness Measurement · TC5 · 2007 · Download
With the aim to extract the mechanical properties of small volumes of materials, nowadays several methods have been proposed and are applied in practice. How to compare the results of these methods, therefore, gains more and more interests. Instrumented indentation with a spherical indenter on circularly supported freestanding thin films is believed to be an effective way to connect and compare the material testing methods including nanoindentation and micro-tensile testing. In this paper an experimental setup for making indents on free-standing films is presented, in which a modified...
Symposium on Recent Advancements in the Theory and Practice of Hardness Measurement · TC5 · 2007 · Download
Among the various methods for characterizing the mechanical properties of small volume of materials, nano-indentation testing has gained more and more interests, due to its simple principle, the easy realization and application for various specimen, etc. However, nano-indentation instruments often fail to measure the mechanical properties of materials which demonstrate heavy creep, plasticity, etc. To overcome the disadvantages of nano-indentation instruments, here a new approach to develop the next generation of nano-indentation systems is proposed, in which the well-developed MEMS...
Symposium on Recent Advancements in the Theory and Practice of Hardness Measurement · TC5 · 2007 · Download
The overview on the development tendencies clarifies that the main developments refer to the increase of productivity and of the accuracy of measurements. With the development of new materials also new optimum hardness measuring methods are developed. Great efforts are undertaken to enlarge the information content of hardness measuring methods. In this connection great perspectives can be ascribed to the instrumented indentation test.
Symposium on Recent Advancements in the Theory and Practice of Hardness Measurement · TC5 · 2007 · Download
All of hardness testing methods now in use were invented about a century ago but it was after the World War II that the international conformity of the test results was required and that the standardization of the testing methods and testing machines was investigated and promoted. In this paper, the historical role of four international organizations, CIPM, IMEKO, OIML and ISO for the progress of the standardization of hardness testing and on the development of the metrological standards of hardness is reviewed together with some remark on the discussions related to the definition of...
Symposium on Recent Advancements in the Theory and Practice of Hardness Measurement · TC5 · 2007 · Download
In this paper it is presented the activity for recording the patients’ data using electro- medical apparatus. These recording are made in different environmental conditions to analyze the influences of the ambient temperature and the quality of air on the stability and waking behavior and on the level capacity effort. The results are presented in the final part of the paper.
In this paper it is presented the screening method to study the behavior of the human body in different situation: relaxed, before and after an effort in the environmental space. The human subjects have a good health and the recordings are made using a special system for record and analyze the human body stability behavior answer. It is very important to establish in these researches the methodology to record the information’s taking in account the interactions of the human body with environment (with or without open eyes, with or without the sounds in background, temperature, air pollution...