André L. M. Costa, David J. Shuman, Renato R. Machado, Margareth S. Andrade
A major factor in calibrating a depth-sensing indentation tester is to determine its load-frame compliance. In this work a simplified theoretical approach and a computerized iterative method were developed to calculate the load-frame compliance of our laboratory commercial instrumented indentation tester. In addition, this research discusses many of the problems associated with the calibration of this type of testing machine. Three materials were used for the load-unload tests: fused silica, 6066-O aluminum and electrolytic copper. A value of load-frame compliance of 0,23 nm/mN was obtained...
Hardness Measurements Theory and Application in Laboratories and Industries
· TC5
· 2004
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Laurence Brice
As part of the UK’s National Measurement System Mass Programme, and as a result of industrial demand, it was decided to establish a Martens hardness calibration service. This report describes the basis of Martens hardness measurement, work done to determine the ability of NPL’s 1,5 kN hardness machine to measure Martens hardness, the process of establishing the calibration service, and the setting up of instrumented indentation hardness tests.
Hardness Measurements Theory and Application in Laboratories and Industries
· TC5
· 2004
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Giulio Barbato, Alessandro Germak
Recently, in the framework of the Working Group on Hardness (WGH) of the Consultative Committee for Mass and Related Quantities (CCM) of the Comité International des Poids et Mesures (CIPM), the opportunity to improve the definitions of the hardness scales has been discussed. In this paper is investigated, from the theoretical point of view, the benefits in terms of decreasing of uncertainty subsequently to the approval of new definitions. The analysis will be done on the most important Rockwell, Vickers and Brinell hardness scales, but it will be possible to extend the benefits easily to...
Hardness Measurements Theory and Application in Laboratories and Industries
· TC5
· 2004
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Giulio Barbato, Alessandro Germak, Claudio Origlia, Francesco Turotti, Manfredo Vattasso
In the framework of the standardization and laboratory activities concerning the calibration of hardness testers, in particular for indirect verification there are some questions to be answered to decide an efficient metrological confirmation strategy: a) how many points on each scale shall be checked? b) How many levels of the indentation scale shall be checked? c) How many levels of forces shall be checked? d) Is the correlation between indirect results and direct results strong enough to allow a partial check of the hardness scales of the tester? A number of tests have been made and the...
Hardness Measurements Theory and Application in Laboratories and Industries
· TC5
· 2004
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V.Augutis, V,Vasauskas, D.Gailius, S.Jacenas
There is a demand of a system for the nondestructive control of one of the basic quality parameters for wood-based low-density boards (Softboard). A relatively non-destructive method was analyzed on a purpose to find a parameter to measure that has the biggest possible correlation with the bending strength. 13 different softboards were investigated using two different techniques. The boards were tested using another two non-destructive methods: velocity measurement of ultrasonic Lamb waves and impact parameters measurement. Out of all experiment results the highest correlation between...
Hardness Measurements Theory and Application in Laboratories and Industries
· TC5
· 2004
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Edward Aslanyan, Alexander Doynikov, Victor Pivovarov, Igor Temnitsky, Vasily Shlegel, Denis Golotvin, Rustem Fazliakhmetov
A new approach to portable hardness testers has been developed and introduced. It makes it possible to inspect hardness by one and the same hardness tester applying both, the ultrasonic contact impedance method and rebound method. Hardness tester wide possibilities which allow to inspect hardness of metal and alloy products with all standardized scales (Rockwell, Brinell, Vickers and Shore) have been demonstrated. The possibility to improve the precision of portable hardness testers of this type by calibrating them for each of the above listed scales with hardness reference blocks only...
Hardness Measurements Theory and Application in Laboratories and Industries
· TC5
· 2004
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John Ndanusa Akanya, Obiora Ferdinand Manafa
Standards Organisation of Nigeria (SON) was established by Decree No. 56 of 1971 and statutorily charged with the responsibility for National Policy on Metrology, Standards, Testing and Quality Control (MSTQ) in Nigeria. Standardization activities carried out by SON range from development and approval of standards, quality assurance, inspection and testing, certification and calibration. Hardness measurement plays a vital role in Standardization. Product and System certification programmes of SON have recorded a considerable number of hardness measurements in industries, oil & gas...
Hardness Measurements Theory and Application in Laboratories and Industries
· TC5
· 2004
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G.W. Bahng, N.H. Tak, J.Y. Song and J.H. Hahn
The direct verification of Rockwell testing machines comprises four parts such as test force, indenter, depth measuring device, and testing cycle as seen in ISO 6508-2. Among them, the verification of testing cycle is generally carried out by using a stopwatch on industrial sites, which is not so reliable. In addition to this, most of commercial hardness testing machines produced nowadays are automatically controlled by the embedded software, which makes it much more difficult to calibrate the testing cycle. It implies that even though hardness testing machines are advanced more, the...
Symposium on Recent Advancements in the Theory and Practice of Hardness Measurement
· TC5
· 2007
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Takashi Usuda, Hajime Ishida, Yutaka Seino, Satoshi Takagi, Koichiro Hattori, Hidetaka Imai
With reference to CIPM-MRA (Mutual recognition of national measurement standards and of calibration and measurement certificates issued by national metrology institutes), APMP (Asia Pacific Metrology Programme) have established 11 TCs (Technical Committees) including TCM (Technical Committee of Mass related quantities) which discusses hardness related issues in APMP. Under the TC activities, the guidelines and procedures for accepting CMCs (Calibration and Measurement Capabilities) and QS (Quality System) have been drawn up by taking closer cooperation with the JCRB (Joint Committee of the...
Symposium on Recent Advancements in the Theory and Practice of Hardness Measurement
· TC5
· 2007
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Hiroshi Yamamoto , Takashi Yamamoto
The sources of problems with a hardness testing machine that are detectable via day-to-day inspection using hardness standard blocks, or indirect verification, can be roughly divided into three: the indenter, the test force, and the indentation measuring apparatus. If any problems are detected, repair or recalibration of the testing machine, focusing on the aforementioned three factors, is carried out based on the results of verifying the direct accuracies of that machine. These efforts have been accumulated to acquire the high level of hardness testing technology as is available now. This...
Symposium on Recent Advancements in the Theory and Practice of Hardness Measurement
· TC5
· 2007
· Download