Effects of Thickness and Indenter Geometry in Nanoindentation of Nickel Thin Films

2003 ◽  
Vol 795 ◽  
Author(s):  
Padma Parakala ◽  
Reza A. Mirshams ◽  
Seifollah Nasrazadani ◽  
Kun Lian
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Indentation Size Effect ◽  
Deformation Mechanisms ◽  
Indentation Size ◽  
Depth Of Penetration ◽  
Nickel Thin Films ◽  
Cube Corner ◽  
Depth Effects ◽  
Indenter Geometry

ABSTRACTEffects of thickness and tip geometry on Ni thin films deposited on Cu substrate were studied using nanoindenter. The deformation mechanisms in correlation to hardness measurements were discussed at various loads and depths of penetration. The Berkovich, Cube corner and Conical tips have been used in this study. Initially, the hardness and modulus of elasticity were measured at a depth of 10% of film thickness. The depth of penetration was increased to 20% to observe the depth effects. Analysis of data showed that there is an Indentation Size Effect (ISE) irrespective of indenter tip geometries.

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.

scholarly journals Atomic force microscopy study of nanoindentation deformation and indentation size effect in MgO crystals

1999 ◽  
Vol 14 (10) ◽  
pp. 3973-3982 ◽  
Author(s):  
K. Sangwal ◽  
P. Gorostiza ◽  
J. Servat ◽  
F. Sanz
Keyword(s):  
Experimental Data ◽  
Plastic Deformation ◽  
Atomic Force Microscopy ◽  
Size Effect ◽  
Deformation Zone ◽  
Indentation Size Effect ◽  
Indentation Size ◽  
Depth Of Penetration ◽  
Force Microscopy ◽  
Atomic Force

The dependences of various nanoindentation parameters, such as depth of penetration d, indentation diameter a, deformation zone radius R, and height h of hills piled up around indents, on applied load were investigated for the initial (unrecovered) stage of indentation of the (100) cleavage faces of MgO crystals by square pyramidal Si tips for loads up to 10 μN using atomic force microscopy. The experimental data are analyzed using theories of elastic and plastic deformation. The results revealed that (i) a, R, and h linearly increase with d; (ii) the development of indentation size and deformation zone and the formation of hills are two different processes; (iii) the load dependence of nanohardness shows the normal indentation size effect (i.e., the hardness increases with a decrease in load); and (iv) there is an absence of plastic deformation involving the formation of slip lines around the indentations. It is found that Johnson's cavity model of elastic–plastic boundary satisfactorily explains the experimental data. The formation of hills around indentations is also consistent with a new model (i.e., indentation crater model) based on the concept of piling up of material of indentation cavity as hills.

Length-scale-based hardening model for ultra-small volumes

2004 ◽  
Vol 19 (10) ◽  
pp. 2812-2821 ◽  
Author(s):  
J.M. Jungk ◽  
W.M. Mook ◽  
M.J. Cordill ◽  
M.D. Chambers ◽  
W.W. Gerberich ◽  
...  
Keyword(s):  
Thin Films ◽  
Silicon Nanoparticles ◽  
Indentation Size Effect ◽  
Back Stress ◽  
Length Scale ◽  
Copper Films ◽  
Indentation Size ◽  
Composite Effect ◽  
Hardening Behavior ◽  
Surface Length

Understanding the hardening response of small volumes is necessary to completely explain the mechanical properties of thin films and nanostructures. This experimental study deals with the deformation and hardening response in gold and copper films ranging in thickness from 10 to 400 nm and silicon nanoparticles with particle diameters less than 100 nm. For very thin films of both gold and copper, it was found that hardness initially decreases from about 2.5 to 1.5 GPa with increasing penetration depth. Thereafter, an increase occurs with depths beyond about 5–10% of the film thickness. It is proposed that the observed minima are produced by two competing mechanisms. It is shown that for relatively deep penetrations, a dislocation back stress argument reasonably explains the material hardening behavior unrelated to any substrate composite effect. Then, for shallow contacts, a volume-to-surface length scale argument relating to an indentation size effect is hypothesized. A simple model based on the superposition of these two mechanisms provides a reasonable fit to the experimental nanoindentation data.

Formation of Self-Affine Surface During the Growth of Nickel Thin Films

1994 ◽  
Vol 367 ◽  
Author(s):  
M.V.H. Rao ◽  
V. Srinivas ◽  
B.K. Mathur ◽  
K.L. Chopra
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Surface Structure ◽  
Film Growth ◽  
The Self ◽  
Affine Surface ◽  
Nickel Thin Films ◽  
Topographic Data ◽  
Shape And Size

AbstractThin films of nickel deposited on various substrates have been investigated by using an STM. Topographic data recorded at different stages of the film growth reveal that the surface structure at one location of the film resemble that at another location of the same film. The repetitive structures are made up of a few coalescing clusters and forming exactly similar looking islands. As the film thickness increases, the shape and size of these repetitive patterns changes but the self-affinity of the surface structure is maintained.

Indentation and Finite Element Modelling Investigations of the Indentation Size Effect in Aluminium Coatings on Borosilicate Glass Substrates

2003 ◽  
Vol 795 ◽  
Author(s):  
I. Spary ◽  
N. M. Jennett ◽  
A. J. Bushby
Keyword(s):  
Thin Films ◽  
Finite Element ◽  
Size Effect ◽  
Yield Stress ◽  
Borosilicate Glass ◽  
Quantitative Methods ◽  
Indentation Size Effect ◽  
Surface Profile ◽  
Indentation Size ◽  
Plastic Properties

ABSTRACTNanoindentation is one of the few available methods and the most commercially widespread technique for investigating the elastic and plastic properties of small volumes such as thin films. Quantitative methods for obtaining the indentation (plane strain) modulus and hardness of a coating have been published and finite element models (FEM) of the elastic-plastic response of indentation have been developed. Comparison of the FEM output with actual indentation data has shown that, as the indentation size reduces, the apparent yield stress of the material increases. We have shown that the increase in yield stress is predictable and falls on a master curve (MRS Symp. Proc., Vol 788, p123, 2003). Predictions have been tested and agree for a range of metals (Cu, Al, W, Ir). This points to there being a fundamental length scale for dislocation-based deformation and raises the question as to whether the yield stress of thin films may be altered by reducing thickness. This study therefore investigates the indentation response of Al coatings on Borosilicate glass as a function of coating thickness and indentation depth. FEM of the indentation contact will be compared with indentation data and AFM measurements of the surface profile to investigate the relative contributions of the indentation size effect and the effect of hardening due to the additional constraint of substrate proximity to the plastic zone.

An Investigation of Film Thickness Effect on Mechanical Properties of Au Films Using Nanoindentation Techniques

2005 ◽  
Vol 875 ◽  
Author(s):  
Yifang Cao ◽  
Zong Zong ◽  
Wole Soboyejo
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Electron Beam ◽  
Film Thickness ◽  
Size Effects ◽  
Experimental Studies ◽  
Thickness Effect ◽  
Length Scale ◽  
Indentation Size ◽  
Au Thin Films

AbstractThis paper presents the results of nanoindentation experimental studies of Au thin films with different thicknesses. The effects of film thickness and microstructure on the hardnesses of electron-beam deposited Au films were studied in terms of Hall-Petch relationship. The effects of different thicknesses on indentation size effects (ISE) are explained within the framework of mechanism-based strain gradient (MSG) theory using the concept of microstructural length scale.

scholarly journals The Correlation of Indentation Size Effect Experiments with Pyramidal and Spherical Indenters

2001 ◽  
Vol 695 ◽  
Author(s):  
J. G. Swadener ◽  
E. P. George ◽  
G. M. Pharr
Keyword(s):  
Size Effect ◽  
Work Hardening ◽  
Size Effects ◽  
Indentation Size Effect ◽  
Experimental Results ◽  
Indentation Size ◽  
Depth Of Penetration ◽  
Wide Range ◽  
Sphere Radius

ABSTRACTExperiments were conducted in annealed iridium using pyramidal and spherical indenters over a wide range of load. For a Berkovich pyramidal indenter, the hardness increased with decreasing depth of penetration. However, for spherical indenters, hardness increased with decreasing sphere radius. Based on the number of geometrically necessary dislocations generated during indentation, a theory that takes into account the work hardening differences between pyramidal and spherical indenters is developed to correlate the indentation size effects measured with the two indenters. The experimental results verify the theoretical correlation.

scholarly journals INDENTATION SIZE EFFECT IN HIGH PRESSURE TORSION PROCESSED HIGH ENTROPY ALLOY

2020 ◽  
Vol 27 ◽  
pp. 141-144
Author(s):  
Petr Haušild ◽  
Jakub Čížek ◽  
Jaroslav Čech ◽  
Jiří Zýka ◽  
Hyoung Seop Kim
Keyword(s):  
High Pressure ◽  
Size Effect ◽  
Indentation Size Effect ◽  
High Pressure Torsion ◽  
High Entropy Alloy ◽  
Indentation Size ◽  
Depth Of Penetration ◽  
Slow Cooling ◽  
Cast Sample ◽  
High Entropy

High entropy alloy HfNbTaTiZr in as cast conditions and after high pressure torsion straining was characterized by nanoindentation. The length-scale dependent material response (indentation size effect) was characterized by indentation at various indentation depths. Hardness dependence on the characteristic length (depth of penetration) indicated decomposition of disordered high entropy alloy in the as cast sample, which probably occurred during slow cooling after casting. Subsequent severe plastic deformation by high pressure torsion led on the other hand to the short-range disorder of (originally partially decomposed as cast) structure. Further hardening was generated during high pressure torsion by the mechanisms of grain refinement and increasing dislocation density.

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