The relationship between the deformation and the indentation size effect (ISE)

2019 ◽  
Vol 116 (6) ◽  
pp. 622
Author(s):  
Jozef Petrík ◽  
Peter Blaško ◽  
Mária Mihaliková ◽  
Andrea Vasilňáková ◽  
Vojtech Mikloš

The aim of the submitted work is to study the relationship between the local deformation and the indentation size effect (ISE). A local value of reduction of the area (Z) was used as the measure of the deformation. Applied loads in the micro-hardness test ranged between 0.09807 to 0.9807 N. The micro-hardness was measured on the cross section in the longitudinal axis of the fractured sample after the uniaxial tension test. The material of the sample was 99.5% aluminium. The influence of both load and deformation on the ISE was evaluated by the analysis of variance (ANOVA). The influence of the load was also evaluated by Meyer’s index n, PSR method, and Hays–Kendall approach. The influence of both factors on the measured value of micro-hardness and therefore on the ISE is statistically significant. The ISE is normal in the areas with high deformation, on the contrary, in areas with low deformation, it has a “reverse” character. The difference between load independent “true hardness” and measured micro-hardness HV0.05 increases with increasing deformation.

Author(s):  
J. Petrík ◽  
P. Blaško ◽  
M. Mihaliková ◽  
V. Mikloš

The aim of the submitted work is to study the relationship between the local deformation and the Indentation Size Effect (ISE). A local value of reduction of the area (Z) was used as the measure of the deformation. Applied loads in the micro-hardness test ranged between 0.09807 N to 0.9807 N. The micro-hardness was measures on the cross section in the longitudinal axis of the fractured sample after the uniaxial tension test. The material of the sample was 99.5% aluminium. The influence of the load was also evaluated by Meyer's index n, PSR method and Hays therefore on the ISE statistically significant. The ISE is normal in the areas with high deformation, on the contrary, in areas with low deformation it has the "reverse" character. The difference between load independent "tru hardness" and measured micro-hardness HV0.05 increases with increasing deformation


2011 ◽  
Vol 492 ◽  
pp. 9-13
Author(s):  
Bei Xu ◽  
Jiang Hong Gong

The load-displacement curves for a series of ceramic and glass samples were recorded continuously during the low-load Vickers hardness testing. Then the hardnesses of all samples were determined by analyzing the unloading curves. It was found that all the test materials exhibit indentation size effect (ISE) similar to that observed in nanoindentation testing. The applicability of the proportional specimen resistance (PSR) model and the modified PSR model was then examined using the measured indentation data.


2011 ◽  
Vol 18 (2) ◽  
pp. 223-234 ◽  
Author(s):  
Jozef Petrík ◽  
Pavol Palfy

The Influence of the Load on the HardnessThe objective of the submitted paper is to analyze the influence of the load on the calibration of micro-hardness and hardness testers. The results were validated by Measurement Systems Analysis (MSA), Analysis of Variance (ANOVA) and Z-score. The relationship between the load and micro-hardness in calibration of micro-hardness testers cannot be explained by Kick's Law (Meyer's index "n" is different from 2). The conditions of Kick's Law are satisfied at macro-hardness calibration, the values of "n" are close to 2, regardless of the applied load. The apparent micro-hardness increases with the increase of the load up to 30 g; the reverse indentation size effect (ISE) behavior is typical for this interval of the loads. The influence of the load on the measured micro-hardness is statistically significant for majority of calibrations.


2013 ◽  
Vol 391 ◽  
pp. 23-28 ◽  
Author(s):  
I. Nyoman Budiarsa

The indentation size effect (ISE) in Vickers test using steel as a typical model material group with selected heat treatments (annealed or tempered) has been investigated and analysed. Systematically hardness test were performed within a commonly used micro-load range. The ISE data was analysed by fitting data following the Meyer power law and the proportional specimen resistance (PSR) models and the link between ISE and the hardness-to-modulus ratio (H/E) was discussed. The results show that the ISE data correlated well with the Meyers power law (P= A.dn) and the PSR (P/d=a1+a2d) models. The ISE power law index n exhibited a reasonable agreement with the hardness-elastic modulus ratio (H/E), which potentially could be used the relative contributions of plastic and elastic deformation contact area under indentation load and as a measurable input for inverse material parameter prediction.


2010 ◽  
Vol 662 ◽  
pp. 13-26 ◽  
Author(s):  
L.M. Brown

The flow of material out from under regions in compression must occur by the operation of many slip systems, which together produce rotational flow. Such flow requires the accumulation of geometrically necessary dislocations, and leads to the indentation size effect: smaller indents produce higher hardness, a component of the hardness being inversely proportional to the square-root of the indenter size. A pattern of flow in polycrystals which satisfies both continuity of normal stress and continuity of matter at boundaries can be achieved by rotational flow, and it leads to a grain-size effect. Under most circumstances, the flow stress has a component which is inversely proportional to the square-root of the grain size, the Hall-Petch law. The flow is accompanied by the build-up of internal stress which can be relieved by intercrystalline cracking, thereby limiting the cohesive strength of polycrystals. The relationship between these ideas and traditional views is briefly explained, and an analysis is given of recent experimental results.


2013 ◽  
Vol 535-536 ◽  
pp. 227-230 ◽  
Author(s):  
Muhammad Taureza ◽  
Sylvie Castagne ◽  
Samuel Chao Voon Lim

Contact simulation involving asperities was developed by assuming that the deformation by asperities is equivalent to the deformation by an indenter in a hardness test. Consequently, depth dependent flow stress curves were derived from the indentation size effect model from Abu Al-Rub and were used to simulate the influence of the number of asperities involved during contact on the distribution of contact pressure and the value of effective friction coefficient. Results from simulations suggested that multiplying the number of asperities in contact, when the size of the asperities is comparable to the size of the apparent contact, is not followed by proportional multiplication of the reaction forces. The competing phenomena observed in the simulation are then proposed as an explanation to friction size effect occurring in microforming.


2016 ◽  
Vol 61 (4) ◽  
pp. 1819-1824 ◽  
Author(s):  
J. Petrík

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.


2009 ◽  
Vol 24 (5) ◽  
pp. 1693-1699 ◽  
Author(s):  
N. Li ◽  
L. Liu ◽  
K.C. Chan

The deformation behavior and indentation size effect (ISE) in amorphous and crystallized Pd40Cu30Ni10P20 alloy were comparatively studied through instrumented nanoindentation. It was found that the two alloys showed different deformation behaviors, the amorphous alloy exhibited conspicuous pop-in events in the load-depth (P-h) curve, while the crystallized alloy showed a relatively smooth P-h curve. In addition, the indentation hardness was observed to decrease with increasing penetration depth in the two alloys, exhibiting a significant ISE. However, the crystallized alloy displayed a sharper reduction of hardness with indentation depth as compared to the amorphous alloy, indicating a more significant indentation size effect in the crystalline alloy. The structure difference and friction factor associated with the surface residual stress are taken into account to interpret the difference in the deformation behavior and indentation size effect of the two alloys.


2011 ◽  
Vol 53 (1-2) ◽  
pp. 48-53 ◽  
Author(s):  
Tomislav Filetin ◽  
Sanja Šolić ◽  
Irena Žmak

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