scholarly journals Analysis of the Indentation Size Effect in the Microhardness Measurements inB6O

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Ronald Machaka ◽  
Trevor E. Derry ◽  
Iakovos Sigalas ◽  
Mathias Herrmann
Keyword(s):  
Vickers Microhardness ◽  
Scaling Law ◽  
Indentation Test ◽  
Indentation Load ◽  
Indentation Size ◽  
Load Dependence ◽  
Proportional Specimen Resistance ◽  
Resistance Model ◽  
Multifractal Scaling ◽  
Intercomparison Study

The Vickers microhardness measurements of boron suboxide (B6O) ceramics prepared by uniaxial hot-pressing was investigated at indentation test loads in the range from 0.10 to 2.0 kgf. Results from the investigation indicate that the measured microhardness exhibits an indentation load dependence. Based on the results, we present a comprehensive model intercomparison study of indentation size effects (ISEs) in the microhardness measurements of hot-pressed B6O discussed using existing models, that is, the classical Meyer's law, Li and Bradt's proportional specimen resistance model (PSR), the modified proportional specimen resistance model (MPSR), and Carpinteri's multifractal scaling law (MFSL). The best correlation between literature-cited load-independent Vickers microhardness values, the measured values, and applied models was achieved in the case of the MPSR and the MFSL models.

scholarly journals On the Load Dependence of Micro-Hardness Measurements: Analysis of Data by Different Models and Evaluation of Measurement Errors

2016 ◽  
Vol 61 (4) ◽  
pp. 1819-1824 ◽  
Author(s):  
J. Petrík
Keyword(s):  
Measurement Errors ◽  
Applied Load ◽  
Indentation Size Effect ◽  
Micro Hardness ◽  
Indentation Size ◽  
Load Dependence ◽  
Proportional Specimen Resistance ◽  
Dispersion Zone ◽  
The Relationship ◽  
Uncertainty Of Results

AbstractThe influence of applied loads between 0.09807 N and 0.9807 N on measured values of micro-hardness was evaluated by Meyer’s index n, proportional specimen resistance model (PSR) and Hays – Kendall methods, Total Dispersion Zone and Analysis of Variance (ANOVA). The measurement was repeated 6 times using the same hardness reference block with standard hardness Hc= 327 HV0.05 as a sample. The influence of the load on the measured value of micro-hardness is statistically significant, and the relationship between applied load and micro-hardness manifests reverse indentation size effect (ISE) for most of “measurements”. The high value of the uncertainty of results can affect the existence and nature of ISE, especially at low loads.

Mechanical Properties of CaF2 Single Crystal Substrates Determined from Nanoindentation Techniques

1996 ◽  
Vol 436 ◽  
Author(s):  
A. Aruga ◽  
R. B. Inturi ◽  
J. A. Barnard ◽  
R. C. Bradt
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Single Crystal ◽  
Power Law ◽  
Indentation Size Effect ◽  
Berkovich Indenter ◽  
Indentation Size ◽  
Proportional Specimen Resistance ◽  
Caf2 Single Crystal ◽  
Resistance Model

AbstractCaF2 single crystals are interesting substrate materials for deposition of thin films. Its structure is cubic and it cleaves on {111} planes. CaF2, whose hardness has been reported to be 4 on the Moh's scale, is plastic and soft. In this study, the mechanical properties such as hardness(H) and Young's modulus(E) of single crystal CaF2 mineral were measured by using a nanoindenter with a Berkovich indenter normal to (100) and (111) planes. A normal indentation size effect (ISE) in accordance with the traditional power law and the proportional specimen resistance model (PSR) of Li and Bradt [1] was observed. The values of E and H on (100) plane are larger than those on (111) plane and these values on both planes decrease with increase in time during the hold segment. The effect of displacement rate on mechanical properties of (100) and (111) surfaces is also studied.

scholarly journals THE AUTOMATIC TESTERS IN MICROHARDNESS MEASUREMENT AND ISE EFFECT

2016 ◽  
Vol 22 (3) ◽  
pp. 195
Author(s):  
Jozef Petrík ◽  
Peter Blaško ◽  
Jana Bidulská ◽  
Anna Guzanová ◽  
Iveta Sinaiová
Keyword(s):  
Applied Load ◽  
Statistical Significance ◽  
Z Score ◽  
Micro Hardness ◽  
Indentation Size ◽  
Proportional Specimen Resistance ◽  
Resistance Model ◽  
Dispersion Zone ◽  
The Impact ◽  
Hardness Values

<p>The measurement of micro-hardness with applied loads 0.09807 N, 0.24518 N, 0.49035 N and 0.9807 N has been carried out by three automatic and one manually-operated micro-hardness testers. The certified reference material (CRM) was the tested sample. Each operator obtained readings of the tester which she/he normally operates. The measurement was repeated after thirty months. The influence of the testers and their stability, as well as applied load on the measured values of the micro-hardness and the indentation size phenomenon (ISE), were evaluated. The parametric and non-parametric tests, Analysis of Variance (ANOVA), Z-score and Total Dispersion Zone were used for the evaluation of the statistical significance of obtained factors. The ISE was evaluated using Meyer’s and Proportional Specimen Resistance model and also by Hays – Kendall approach. The variability of measured values of the micro-hardness values and parameters ISE is high despite the use of automatic hardness testers with practically excluding the impact of the operator. The results are affected by testers and by used testers and by applied loads. The measurement system can not be considered to be stable.</p>

Vickers hardness indentation size effect in selective laser melted MS1 maraging steel

2019 ◽  
pp. 095440621989230 ◽  
Author(s):  
Sebastian Balos ◽  
Dragan Rajnovic ◽  
Leposava Sidjanin ◽  
Olivera Eric Cekic ◽  
Slobodan Moraca ◽  
...  
Keyword(s):  
Size Effect ◽  
Cross Sections ◽  
Vickers Hardness ◽  
Indentation Size Effect ◽  
Full Range ◽  
Indentation Size ◽  
Load Dependence ◽  
Proportional Specimen Resistance ◽  
Heat Treated ◽  
Correlation Factors

In this paper, selective laser melting fabricated specimens in non-heat-treated and heat-treated conditions were subjected to Vickers microhardness testing, by using a full range of loadings: 10, 25, 50, 100, 200, 300, 500, and 1000 g. Microhardness of longitudinal sections and cross-sections were correlated and the obtained values were plotted against loadings and indentation size effect was studied, in order to find the optimal loading range, that gives the material true microhardness, or load-independent hardness. The load dependence of the measured Vickers hardness values was described quantitatively through the application of the Meyer’s law, proportional specimen resistance, and the modified proportional specimen resistance model. It was found that the microhardness rises as the loading is higher, causing a reversed indentation size effect, clearly indicating the range of true hardnesses of the tested material. Also, proportional specimen resistance and modified proportional specimen resistance models were found to have the highest correlation factors indicating their higher adequacy compared to Meyer’s prediction model.

scholarly journals The load dependence of the micro-hardness of the blast furnace slag

10.30544/512 ◽  
2020 ◽  
Vol 26 (3) ◽  
pp. 329-340
Author(s):  
Jozef Petrík ◽  
Peter Blaško ◽  
Vojtech Mikloš ◽  
Alena Pribulová ◽  
Peter Futaš ◽  
...  
Keyword(s):  
Blast Furnace ◽  
Energy Cost ◽  
Blast Furnace Slag ◽  
Environmental Problem ◽  
Indentation Size Effect ◽  
Grinding Process ◽  
Micro Hardness ◽  
Indentation Size ◽  
Load Dependence ◽  
Furnace Slag

Deposits of old blast-furnace slag are an environmental problem. The slag’s hardness is an important for calculation of the energy cost for crushing and grinding process. Due to its porosity, measurement of the (macro) hardness is. To adapt the dimensions of the indentations to the character of the slag, it is necessary to apply loads in the range of micro-hardness. The purpose of this paper is to evaluate the influence of load on the micro-hardness - the Indentation Size Effect (ISE) using Meyer’s, Hays-Kendall and PSR methods. ISE for all samples is “normal”, the slag’s basicity affects micro-hardness and ISE.

Vickers Microhardness Dependence Load and Determining of Tensile Strength of HQ 705 Steel from Microhardness Curves

2016 ◽  
Vol 842 ◽  
pp. 43-52 ◽  
Author(s):  
Viktor Malau ◽  
Latif Arifudin
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Alloy Steel ◽  
Vickers Hardness ◽  
Vickers Microhardness ◽  
Hardness Test ◽  
Indentation Load ◽  
Holding Time ◽  
Raw Material ◽  
Vickers Hardness Number

Vickers microindentation hardness test has been applied for a long time to determine the mechanical properties of a small volume of samples. The procedure of this hardness test consists of using a constant load on a rigid indenter and measuring the dimensions of the indenter residual impression (indentation imprint) on the surface of the sample tested after loading and unloading. The objective of this research is to characterize the mechanical properties and material constants of HQ (High Quality) 705 alloy steel mainly its VHN (Vickers Hardness Number) and tensile strength before and after quenching and tempering heat treatments. The characterization is based on Vickers microhardness dependence load curves.Quenching treatment was performed in a furnace by heating the samples at austenite temperature of 850 o C with holding time of two hours and then the samples were rapidly cooled in oil bath. Tempering processes were conducted by heating again the quenching samples to temperatures of 150, 200, 250, 300, 350, 400, 450, 500, 550 and 600 o C with holding time of two hours for each sample. Finally, all samples were slowly cooled in atmospheric temperature. The mechanical properties of samples were characterized by using Vickers microhardness dependence load curves.The results show that VHN (Vickers Hardness Number) depends on indentation load and VHN increases with increment of load for indentation load lower than 5 N. VHN is almost constant for indentation load greater than 5 N. The raw material (without heat treatment) has the VHN and tensile strength of 3413 MPa and 1050.61 MPa respectively and the quenched samples have the VHN and tensile strength of 5407 and 1861 MPa respectively. The Vickers hardness and tensile strength decrease with the increment of tempering temperatures. The higher tempering temperature produces lower hardness and tensile strength. The raw material tensile strength of 1058.8 MPa obtained by tensile test is comparable to its tensile strength of 1050.61 MPa obtained by Vickers indentation. This result indicates that Vickers microindentation is valid to use for evaluating the tensile strength of HQ 705 alloy steel.

Fracture Characteristic of Single Crystalline Silicon Using Nano-Indentation and Finite Element Analysis

2006 ◽  
Vol 306-308 ◽  
pp. 601-606
Author(s):  
Seung Baek ◽  
Jae Mean Koo ◽  
Chang Sung Seok
Keyword(s):  
Fracture Toughness ◽  
Finite Element ◽  
Phase Transformation ◽  
Crystalline Silicon ◽  
Indentation Test ◽  
Indentation Load ◽  
Single Crystalline Silicon ◽  
Element Analysis ◽  
Single Crystalline ◽  
Nano Indentation

Nano-indentation test is used widely to determine the fracture toughness of brittle materials and to provide information on important material properties such as the Young’s modulus and hardness. In this study, using nano-indentation testing, atomic force microscope (AFM), and finite element method (FEM), we performed the indentation fracture toughness and fracture strength measurement for a (100) single crystalline silicon at different load states. In addition, the loads of the phase transformation events during unloading were estimated by the load-depth curves. The phase transformation load and micro-crack propagation events at pop-out during the unloading process depended on the maximum applied indentation load.

Determination of the Elastic-Plastic Properties of 15Kh2MFA Steel with Austenitic Cladding

2013 ◽  
Vol 586 ◽  
pp. 43-46 ◽  
Author(s):  
Aleš Materna ◽  
Jiri Nohava ◽  
Petr Haušild ◽  
Vladislav Oliva
Keyword(s):  
Tensile Test ◽  
Indentation Test ◽  
Strain Curve ◽  
Indentation Load ◽  
Spherical Indentation ◽  
Compression Tests ◽  
Material Interface ◽  
Plastic Properties ◽  
Longitudinal Orientation ◽  
Sufficient Distance

The spherical indentation response of pressure vessel reactor steel with austenitic cladding is investigated both experimentally and numerically. The instrumented indentation test was performed for both materials at a sufficient distance from the bi-material interface, thus the results can be compared with the bulk data obtained from the standard tensile and compression tests. The stress – plastic strain curve for austenitic cladding estimated by a simplified inverse analysis of the indentation load – penetration curve is shifted to a harder response compared with that determined from the tensile test. One of the possible reasons, anisotropy of the cladding metal, was experimentally observed during the compression tests performed in the longitudinal orientation of the tensile test specimens and in the transverse orientation identical with the direction of the material indentation.

Investigation of the Cracking Behaviors by Indentation Based on an In Situ Observation

2014 ◽  
Vol 627 ◽  
pp. 361-364 ◽  
Author(s):  
Yasuhiro Yamazaki
Keyword(s):  
Indentation Test ◽  
Crack Size ◽  
Indentation Load ◽  
In Situ Measurement ◽  
Observation System ◽  
In Situ Observation ◽  
Test Machine ◽  
Transparent Ceramics ◽  
The Relationship

In this paper, an in-situ measurement of crack size as a function of applied indentation load during indentation test was conducted. To perform the in-situ measurement, an instrumented indentation test machine with the in-situ observation system was developed and used. The joints of transparent ceramics by diffusion bonding were prepared as the specimen used in this study. The indentations were performed at the interface of the joints, and in the monolithic transparent ceramics by means of the instrumented indenter with the in-situ observation system. The relationship between crack shape and indentation load, as well as, the effect of the indenter shape on it were discussed.

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