Deformation behavior and indentation size effect in amorphous and crystallized Pd40Cu30Ni10P20 alloy

2009 ◽  
Vol 24 (5) ◽  
pp. 1693-1699 ◽  
Author(s):  
N. Li ◽  
L. Liu ◽  
K.C. Chan
Keyword(s):  
Amorphous Alloy ◽  
Size Effect ◽  
Deformation Behavior ◽  
Indentation Depth ◽  
Indentation Size Effect ◽  
Indentation Hardness ◽  
Indentation Size ◽  
Surface Residual Stress ◽  
Deformation Behaviors ◽  
The Difference

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.

Further analysis of the size effect in indentation hardness tests of some metals

1995 ◽  
Vol 10 (11) ◽  
pp. 2908-2915 ◽  
Author(s):  
M. Atkinson
Keyword(s):  
Size Effect ◽  
Strain Hardening ◽  
Indentation Size Effect ◽  
Plastic Hinge ◽  
Small Scale ◽  
Indentation Hardness ◽  
Vickers Indentation ◽  
Indentation Size ◽  
Hardness Tests ◽  
Indentation Tests

The variation of apparent hardness observed in previously reported Vickers indentation tests of metals is reexamined. Common deseriptions of the effect are shown to be inaccurate: the variation of apparent hardness is monotonic but not simple. The effect is consistent with varying size of a previously postulated “plastic hinge” at the perimeter of the indent. This complexity confers uncertainty on the estimation of characteristic macrohardness from small scale tests. Association of the indentation size effect with friction and with strain hardening is confirmed.

Indentation Size Effect on Hardness of Nanostructured Thin Films

2006 ◽  
Vol 312 ◽  
pp. 363-368 ◽  
Author(s):  
Chun Sheng Lu ◽  
Yiu Wing Mai ◽  
Yao Gen Shen
Keyword(s):  
Thin Films ◽  
Plastic Deformation ◽  
Grain Boundary ◽  
Size Effect ◽  
Indentation Depth ◽  
Indentation Size Effect ◽  
Indentation Size ◽  
Nanostructured Thin Films ◽  
Measured Hardness

Based on nanoindentation techniques, the evaluation of hardness of two nanostructured thin films, AlN and Ti-Al-N, is discussed. In the case of AlN films, the indentation size effect of hardness can be modeled using the concept of geometrically necessary dislocations, whereas in the case of Ti-Al-N films, the measured hardness increases exponentially as the indentation depth decreases. The results show that, as thin films approach superhard, dislocation-based plastic deformation is gradually replaced by grain-boundary mediated deformation.

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
Keyword(s):  
Size Effect ◽  
Indentation Size Effect ◽  
Hardness Test ◽  
Longitudinal Axis ◽  
Local Deformation ◽  
Micro Hardness ◽  
Indentation Size ◽  
High Deformation ◽  
The Difference ◽  
The Relationship

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.

Residual Area Max Depth Model for Nanoindentation Hardness Size Effect of Single Crystal Silicon

2007 ◽  
Vol 339 ◽  
pp. 389-394
Author(s):  
L. Zhou ◽  
Ying Xue Yao ◽  
Shahjada Ahmed Pahlovy
Keyword(s):  
Size Effect ◽  
Single Crystal ◽  
Indentation Size Effect ◽  
Peak Load ◽  
Single Crystal Silicon ◽  
Indentation Hardness ◽  
Indentation Size ◽  
Crystal Silicon ◽  
New Model ◽  
Nanoindentation Hardness

In material nanoindentation hardness testing, the hardness will decrease with the indentation depth or peak load increase, i.e. indentation size effect (ISE). There are several models and equations were proposed to describe ISE. But the variables self-inaccurate in these models and equations, it will affect the result trueness. Single crystal silicon was used for nanoindentation experiments, and max depths were obtained from these experiments. Combining Matlab software, residual areas were obtained by atomic force microscopy (AFM). Based on max depth and residual area, a new model—residual area max depth model was proposed for indentation size effect in nanoindentaion hardness. The new model perhaps can understand and describe ISE in indentation hardness better than other models and equations.

scholarly journals Characterization of strain amplitude-dependent behavior of hardness and indentation size effect of SS400 structural steel

2020 ◽  
Vol 14 (3) ◽  
pp. 15-25
Author(s):  
Nguyen Ngoc Vinh ◽  
Vu Quoc Anh ◽  
Hong Tien Thang
Keyword(s):  
Mechanical Properties ◽  
Cyclic Loading ◽  
Size Effect ◽  
Strain Rate ◽  
Structural Steel ◽  
Indentation Size Effect ◽  
Low Cycle Fatigue ◽  
Indentation Hardness ◽  
Gradient Plasticity ◽  
Indentation Size

In this paper, the continuous stiffness measurement (CSM) indentation is employed to investigate fatigue mechanical properties of structural steel under cyclic loading. For this purpose, several representative analytical approaches were introduced to estimate the basic mechanical properties including Young’s modulus and indentation hardness from the characteristics of the loading/unloading curves. Several experiments including CSM nanoindentation, low-cycle fatigue experiment for four strain amplitude levels, optical microscope (OM), and transmission electron microscopy (TEM) examinations were conducted to observe the variation characteristics of mechanical properties at the microscale and their micro-mechanisms. The microstructural evolution of the specimens deformed by the low-cycle fatigue was observed using the OM and TEM examinations. The standard nanoindentation experiments were then performed at different strain rate levels to characterize the influences of strain rate indentation on hardness of the material. The micro-mechanisms established based on the microstructural evolution and strain gradient plasticity theory were introduced to be responsible for the variation of indentation hardness under cyclic loading. Finally, the indentation size effect (ISE) phenomenon in SS400 structural steel was investigated and explained through the strain gradient plasticity theory regarding geometrically necessary dislocations underneath the indenter tip. The experimental results can be used for practical designs as well as for understanding the fatigue behavior of SS400 structural steel. Keywords: cyclic loading; fatigue; nanoindentation; indentation size effect; strain rate sensitivity; structural steel.

Indentation Size Effects in Ductile and Brittle Materials

2013 ◽  
Vol 586 ◽  
pp. 51-54
Author(s):  
Jaroslav Menčík ◽  
Martin Elstner
Keyword(s):  
Size Effect ◽  
Size Effects ◽  
Indentation Size Effect ◽  
Brittle Materials ◽  
Indentation Hardness ◽  
Indentation Size ◽  
Homogeneous Materials

Indentation hardness of homogeneous materials should be constant. However, at very small depths, the apparent hardness often increases with decreasing imprint size. The paper discusses various cases of this indentation size effect in metals and ceramics and explains the extrinsic and intrinsic reasons.

scholarly journals Effect of Structural Relaxation on the Indentation Size Effect and Deformation Behavior of Cu–Zr–Based Nanoglasses

2021 ◽  
Vol 8 ◽  
Author(s):  
A Sharma ◽  
Sree Harsha Nandam ◽  
Horst Hahn ◽  
K. Eswar Prasad
Keyword(s):  
Size Effect ◽  
Structural Relaxation ◽  
Deformation Behavior ◽  
Indentation Size Effect ◽  
Shear Bands ◽  
Amorphous Structure ◽  
Indentation Load ◽  
Indentation Size ◽  
Show Evidence ◽  
Micro Indentation

In this work, the deformation behavior of as-prepared (AP) and structurally relaxed (SR) Cu–Zr–based nanoglasses (NGs) are investigated using nano- and micro-indentation. The NGs are subjected to structural relaxation by annealing them close to the glass transition temperature without altering their amorphous nature. The indentation load, p, vs. displacement, h, curves of SR samples are characterized by discrete displacement bursts, while the AP samples do not show any of them, suggesting that annealing has caused a local change in the amorphous structure. In both the samples, hardness (at nano- and micro-indentation) decreases with increasing p, demonstrating the indentation size effect. The micro-indentation imprints of SR NGs show evidence of shear bands at the periphery, indicating a heterogeneous plastic flow, while AP NG does not display any shear bands. Interestingly, the shear band density decreases with p, highlighting the fact that plastic strain is accommodated entirely by the shear bands in the subsurface deformation zone. The results are explained by the differences in the amorphous structure of the two NGs.

Nanomechanical Characterization on Zinc and Tin Oxides Nanobelts

2002 ◽  
Vol 740 ◽  
Author(s):  
Minhua Zhao ◽  
Scott Mao ◽  
Zhong Lin Wang ◽  
Fengting Xu ◽  
John A Barnard
Keyword(s):  
Size Effect ◽  
Cross Section ◽  
Indentation Depth ◽  
Indentation Size Effect ◽  
Indentation Size ◽  
Tin Oxides

ABSTRACTNanobelts are a group of materials that have a rectangle-like cross section with typical widths of several hundred nanometers, width-to-thickness ratios of 5 to 10, and lengths of hundreds of micron meters. In this paper, nanoindentations were made on individual ZnO, SnO2 nanobelts and (0001) bulk ZnO by using AFM and Hysitron Triboscope indenters. It was shown that the indentation size effect was still obvious for the indentation depth under 50 nm. It is also demonstrated that nanomaching is possible on nanobelt using AFM tip.

On the interpretation of the indentation size effect (ISE) through gradient theory for Vickers and Berkovich indenters

2016 ◽  
Vol 25 (5-6) ◽  
pp. 161-164 ◽  
Author(s):  
Asterios K. Kampouris ◽  
Avraam A. Konstantinidis
Keyword(s):  
Size Effect ◽  
Indentation Depth ◽  
Indentation Size Effect ◽  
Gradient Theory ◽  
Indentation Size ◽  
Model Predictions

AbstractThe so-called indentation size effect (ISE) observed mainly in nanoindentation measurements with prismatic tips, is theoretically modeled in this article with the use of gradient theory. It is shown that the ISE, i.e. the dependence of the calculated hardness value on the indentation depth, is rather an artifact of the geometry of the tip used, than a phenomenon related to the material tested. The model predictions are compared with nanoindentation measurements of Al specimens.

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