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.

Planar single-crystal thin-films of YAG obtained by ion implantation and thermal exfoliation: Mechanical properties

2012 ◽  
Vol 35 (1) ◽  
pp. 25-28 ◽  
Author(s):  
O. Gaathon ◽  
J.D. Adam ◽  
S.V. Krishnaswamy ◽  
J.W. Kysar ◽  
S. Bakhru ◽  
...  
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Ion Implantation ◽  
Single Crystal

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 Mechanical Properties of 3C-SiC Films for MEMS Applications

2007 ◽  
Vol 1049 ◽  
Author(s):  
Jayadeep Deva Reddy ◽  
Alex A. Volinsky ◽  
Christopher L. Frewin ◽  
Chris Locke ◽  
Stephen E. Saddow
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Silicon Carbide ◽  
Plastic Deformation ◽  
Elastic Modulus ◽  
Single Crystal ◽  
Elastic Contact ◽  
Si Substrates ◽  
Sic Films

AbstractThere is a technological need for hard thin films with high elastic modulus and fracture toughness. Silicon carbide (SiC) fulfills such requirements for a variety of applications at high temperatures and for high-wear MEMS. A detailed study of the mechanical properties of single crystal and polycrystalline 3C-SiC films grown on Si substrates was performed by means of nanoindentation using a Berkovich diamond tip. The thickness of both the single and polycrystalline SiC films was around 1-2 μm. Under indentation loads below 500 μN both films exhibit Hertzian elastic contact without plastic deformation. The polycrystalline SiC films have an elastic modulus of 457 GPa and hardness of 33.5 GPa, while the single crystalline SiC films elastic modulus and hardness were measured to be 433 GPa and 31.2 GPa, respectively. These results indicate that polycrystalline SiC thin films are more attractive for MEMS applications when compared with the single crystal 3C-SiC, which is promising since growing single crystal 3C-SiC films is more challenging.

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.

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.

Indentation Size Effect (ISE) of Vickers Hardness in Steels: Correlation with H/E

2013 ◽  
Vol 391 ◽  
pp. 23-28 ◽  
Author(s):  
I. Nyoman Budiarsa
Keyword(s):  
Size Effect ◽  
Power Law ◽  
Indentation Size Effect ◽  
Hardness Test ◽  
Indentation Load ◽  
Model Material ◽  
Modulus Ratio ◽  
Indentation Size ◽  
Load Range ◽  
Power Law Index

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.

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