Indentation load relaxation experiments with indentation depth in the submicron range

1990 ◽  
Vol 5 (10) ◽  
pp. 2100-2106 ◽  
Author(s):  
W. R. LaFontaine ◽  
B. Yost ◽  
R. D. Black ◽  
C-Y. Li
Keyword(s):  
Indentation Depth ◽  
Metal Films ◽  
Indentation Load ◽  
Hard Substrate ◽  
Flow Properties ◽  
Load Relaxation ◽  
Relaxation Data ◽  
Flow Curves ◽  
Relaxation Experiments

Indentation load relaxation (ILR) experiments with indentation depths in the submicron range are described. Under appropriate conditions, the ILR data are found to yield flow curves of the same shape as those based on conventional load relaxation data. Variations in flow properties as a function of depth in submicron metal films deposited on a hard substrate are detected by the experiments described.

Indentation Load Relaxation Experiments on Al-Si Metallizations

1990 ◽  
Vol 188 ◽  
Author(s):  
W. R. LaFontaine ◽  
B. Yost ◽  
R. D. Black ◽  
Che-Yu Li
Keyword(s):  
Flow Behavior ◽  
Indentation Load ◽  
Load Relaxation ◽  
Depth Of Penetration ◽  
Flow Curves ◽  
Bulk Specimen ◽  
Load Relaxation Test ◽  
Relaxation Experiments ◽  
Film Substrate ◽  
Penetration Depths

ABSTRACTIndentation load relaxation (ILR) experiments with indentation depths in the submicron range are described. The observed flow behavior of a 1μm thick A1-2%Si film deposited on a silicon substrate depended on the depth of penetration. For shallow penetration depths, the shape of the flow curves obtained from this sample are similar to those obtained from a conventional load relaxation test of a bulk specimen. For penetration depths close to the film/substrate interface, the influence of the substrate on the film's deformation behavior was observed.

Spherical indentation load-relaxation of soft biological tissues

2006 ◽  
Vol 21 (8) ◽  
pp. 2003-2010 ◽  
Author(s):  
Jason M. Mattice ◽  
Anthony G. Lau ◽  
Michelle L. Oyen ◽  
Richard W. Kent
Keyword(s):  
Costal Cartilage ◽  
Kidney Tissue ◽  
Biological Tissues ◽  
Indentation Load ◽  
Spherical Indentation ◽  
Load Relaxation ◽  
Soft Biological Tissues ◽  
Long Time ◽  
Constant Displacement ◽  
Soft Biological Materials

Elastic-viscoelastic correspondence was used to generate displacement–time solutions for spherical indentation testing of soft biological materials with time-dependent mechanical behavior. Boltzmann hereditary integral operators were used to determine solutions for indentation load-relaxation following a constant displacement rate ramp. A “ramp correction factor” approach was used for routine analysis of experimental load-relaxation data. Experimental load-relaxation tests were performed on rubber, as well as kidney tissue and costal cartilage, two hydrated soft biological tissues with vastly different mechanical responses. The experimental data were fit to the spherical indentation ramp-relaxation solutions to obtain values of short- and long-time shear modulus and of material time constants. The method is used to demonstrate linearly viscoelastic responses in rubber, level-independent indentation results for costal cartilage, and age-independent indentation results for kidney parenchymal tissue.

scholarly journals Changes in suspension properties of structural modified montmorillonites

Cerâmica ◽  
2001 ◽  
Vol 47 (301) ◽  
pp. 4-8 ◽  
Author(s):  
C. Volzone ◽  
L. B. Garrido
Keyword(s):  
Particle Size ◽  
Structural Disorder ◽  
Physicochemical Characteristics ◽  
Exchange Capacity ◽  
X Ray Diffraction ◽  
Flow Properties ◽  
Flow Curves ◽  
Structural Modifications ◽  
Fine Particle Size ◽  
Cationic Exchange

Rheological changes were found in smectite (Wyoming- and Cheto-type montmorillonites) suspensions after structural modifications. The effect of the particle size and Na+ exchange on the flow curves of 6% wt/wt suspensions of smectites with and without Na2CO3 were examined. Mineralogical, structural and physicochemical characteristics were studied by X-ray diffraction (XRD), infrared spectroscopy (IR), cationic exchange capacity (CEC), Mg2+, Al3+ determinations, particle size distribution and swelling index (SI). Grinding in an oscillating mill modified the particle sizes. The montmorillonite grain size and the structural disorder increased after larger grinding times. The grinding treatment modified the apparent viscosity and the yield stress of the montmorillonite suspensions. The homoionic Na Cheto-type montmorillonite with fine particle size (obtained by grinding) increased the flow properties. Nevertheless, rheological properties were lower than those of suspensions of the Wyoming-type montmorillonite. Montmorillonite-types reacted differently with Na2CO3 additions and this behavior may be related to their structural composition. The Na2CO3 activation improved the flow properties of the original Wyoming-type montmorillonite and after 30 s grinding.

Deformation Properties of a Lead-Tin (95–5) Solder

1986 ◽  
Vol 72 ◽  
Author(s):  
D. Stone ◽  
H. Wilson ◽  
R. Subrahmanyan ◽  
Che-Yu Li
Keyword(s):  
Room Temperature ◽  
Grain Boundary Sliding ◽  
Load Relaxation ◽  
Relaxation Data ◽  
Static Recovery ◽  
Lower Strain ◽  
Deformation Properties ◽  
Solute Interaction ◽  
Show Evidence ◽  
Boundary Sliding

AbstractConsecutive load relaxation tests are performed on a 95 Pb-5 Sn specimen near room temperature, then at 69 ° C and 1°C. The initial relaxation runs at room temperature show evidence of static recovery, which diminishes after a number of load relaxations have been performed. Evidence of grain boundary sliding is also found. The specimen hardens slowly at 69°C, as manifested by successive load relaxation data falling at lower strain rates. At 1°C, the material slowly softens. These temperature effects are believed to result from a dislocation-solute interaction involving tin atoms in the lead matrix.

Study of the ratcheting by the indentation fatigue method with a flat cylindrical indenter: Part I. Experimental study

2006 ◽  
Vol 21 (7) ◽  
pp. 1793-1797 ◽  
Author(s):  
B.X. Xu ◽  
Z.F. Yue
Keyword(s):  
Steady State ◽  
Fatigue Test ◽  
Indentation Depth ◽  
Fatigue Testing ◽  
Indentation Load ◽  
Compression Tests ◽  
Constant Rate ◽  
Secondary Stage ◽  
Indentation Fatigue ◽  
Analogous Equation

Generally, ratcheting is studied on round specimens under tension–compression tests with a nonzero mean load. This work explored the possibility of studying ratcheting by indentation fatigue with a flat cylindrical indenter. In the experiment, emphasis was concentrated on the influence of maximum indentation load (Pmax.), indentation load variance (ΔP = Pmax − Pmin) and frequency of cycling (f) on the indentation depth–cycle curves. The experimental results showed that the indentation depth–cycle curves are analogous to the conventional strain–cycle curve of uniaxial fatigue testing, which has a primary stage of decaying indentation depth per cycle followed by a secondary stage of nearly constant rate of indentation depth per cycle. It was found that the steady-state indentation depth per cycle is an approximate linear function of maximum indentation load (Pmax) and indentation load variance (ΔP = Pmax − Pmin) in the log–log grid. This relationship can be given with a power-law expression as an analogous equation of steady-state ratcheting rate. Further study showed that the influence of frequency of cycling on the steady state indentation depth per cycle can be ignored when the frequency of cycling exceeds a certain value. Finally, comparison was made between the conventional uniaxial fatigue test and indentation fatigue test for the steady-state stage. It was shown that the conventional uniaxial fatigue parameters can be obtained by the indentation fatigue method.

Indentation Load Relaxation Studies of Thin Film-Substrate Systems

1986 ◽  
Vol 72 ◽  
Author(s):  
D. Stone ◽  
W. Lafontaine ◽  
S. Ruoff ◽  
S.-P. Hannula ◽  
B. Yost ◽  
...  
Keyword(s):  
Thin Film ◽  
Aluminum Film ◽  
Indentation Load ◽  
Load Relaxation ◽  
Tin Film ◽  
Relaxation Studies ◽  
Film Substrate

AbstractResults from indentation load relaxation (ILR) tests on thin film-substrate systems are reported. In the case of a 1 pum aluminum film on silicon, the data can be interpreted as reflecting both the properties of the film and the interface between film and substrate. Data from a 37μm TiN film on 304 SS are believed to reflect the combined behavior of the film and substrate.

Statistical Analysis of Experimental Parameters in Continuous Indentation Tests Using Taguchi Method

2003 ◽  
Vol 125 (4) ◽  
pp. 406-411 ◽  
Author(s):  
Eun-chae Jeon ◽  
Joo-Seung Park ◽  
Dongil Kwon
Keyword(s):  
Taguchi Method ◽  
Tensile Properties ◽  
Indentation Depth ◽  
Signal To Noise Ratio ◽  
Indentation Test ◽  
Indentation Load ◽  
Optimum Parameters ◽  
Experimental Parameters ◽  
Indentation Tests ◽  
Continuous Indentation

The continuous indentation test, which applies an indentation load to a material and records the indentation depth, yields indentation tensile properties whose accuracy can vary depending on such experimental parameters as number of unloadings, unloading ratio, maximum depth ratio and indenter radius. The Taguchi method was used to quantify their effects and to determine their optimum values. Using signal-to-noise ratio calculated from the error in the indentation tensile properties, the criterions and the optimum values for the experimental parameters were presented. The indentation tensile properties evaluated with the optimum parameters were in better agreement with the tensile properties.

Indentation Deformation of a Cu47.5Zr19Hf28.5Al5 Bulk-Metallic Glass-Matrix Nanocomposite

2020 ◽  
Vol 20 (3) ◽  
pp. 1530-1539
Author(s):  
Yuan Sun ◽  
Dong Zhang ◽  
Shaojie Xin ◽  
Fuqian Yang
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Matrix Composite ◽  
Vickers Hardness ◽  
Glass Matrix ◽  
Indentation Depth ◽  
Loading Rate ◽  
Indentation Load ◽  
Glass Matrix Composite ◽  
Metallic Glass Matrix Composite

In this work, we study the indentation deformation of a Cu47.5Zr19Hf28.5Al5 bulk-metallic glass-matrix composite and characterize the effects of the indentation-loading rate and the holding time at the peak-indentation load. For the same peak-indentation load, increasing the holding time and/or decreasing the indentation-loading rate cause the increase of the indentation depth. There exists the “bulge” of the unloading curve at the onset of the unloading for small indentation-loading rates. The Vickers hardness is a monotonically increasing function of the indentation-loading rate for the same peak-indentation load. For the indentations with the same loading and unloading time of 30 s and without an intermediate stage at the peak-indentation load, the Vickers hardness of the Cu47.5Zr19Hf28.5Al5 bulk-metallic glass-matrix composite decreases with the increase of the indentation load. The strain energy dissipated through plastic deformation during the indentation is a power-law function of the indentation load with a power index of 3/2, and the energy ratio (total energy/plastic energy) linearly increases with the depth ratio (residual indentation depth/maximum indentation depth).

Analysis of sharp-tip-indentation load–depth curve for contact area determination taking into account pile-up and sink-in effects

2004 ◽  
Vol 19 (11) ◽  
pp. 3307-3315 ◽  
Author(s):  
Yeol Choi ◽  
Ho-Seung Lee ◽  
Dongil Kwon
Keyword(s):  
Finite Element ◽  
Elastic Modulus ◽  
Contact Area ◽  
Indentation Depth ◽  
Indentation Load ◽  
Real Contact Area ◽  
Elastic Deflection ◽  
Contact Depth ◽  
Real Contact ◽  
Pile Up

Hardness and elastic modulus of micromaterials can be evaluated by analyzing instrumented sharp-tip-indentation load–depth curves. The present study quantified the effects of tip-blunting and pile-up or sink-in on the contact area by analyzing indentation curves. Finite-element simulation and theoretical modeling were used to describe the detailed contact morphologies. The ratio f of contact depth, i.e., the depth including elastic deflection and pile-up and sink-in, to maximum indentation depth, i.e., the depth measured only by depth sensing, ignoring elastic deflection and pile-up and sink-in, was proposed as a key indentation parameter in evaluating real contact depth during indentation. This ratio can be determined strictly in terms of indentation-curve parameters, such as loading and unloading slopes at maximum depth and the ratio of elastic indentation energy to total indentation energy. In addition, the value of f was found to be independent of indentation depth, and furthermore the real contact area can be determined and hardness and elastic modulus can be evaluated from f. This curve-analysis method was verified in finite-element simulations and nanoindentation experiments.

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