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.

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 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.

Determination of Time-Dependent Plastic Properties of Metals by Indentation Load Relaxation Techniques

1984 ◽  
Vol 40 ◽  
Author(s):  
Simo-Pekka Hannula ◽  
Donald Stone ◽  
Che-Yu Li
Keyword(s):  
Thin Film ◽  
Indentation Test ◽  
Indentation Load ◽  
Time Dependent ◽  
Relaxation Techniques ◽  
Load Relaxation ◽  
Surface Layers ◽  
Plastic Properties ◽  
Load Relaxation Test

AbstractLoad relaxation testing has been demonstrated to be useful for characterizing the time dependent plastic properties of metals. However, for testing of small material volumes, such as thin film metallizations, thin films, and contact surfaces, conventional load relaxation techniques cannot be used. For such applications an indentation test offers an attractive means for obtaining data necessary for materials characterization. This work shows that an indentation load relaxation test is experimentally feasible for thin film testing. Experiments on brass and beryllium copper samples with or without a gold/nickel plating illustrate different relaxation properties of the substrates and the surface layers. Furthermore, results of experiments on some fcc metals suggest rather simple relations between the conventional uniaxial load relaxation (LR) test and the indentation load relaxation (ILR) test.

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.

Constitutive Modeling of Low-Temperature Superplastic Flow of Ultrafine Ti-6Al-4V Sheet Material

2010 ◽  
Vol 433 ◽  
pp. 235-240 ◽  
Author(s):  
S. Lee Semiatin ◽  
Gordon A. Sargent
Keyword(s):  
Low Temperature ◽  
Flow Behavior ◽  
Sheet Material ◽  
Superplastic Flow ◽  
Flow Softening ◽  
Flow Localization ◽  
Flow Curves ◽  
Localization Model ◽  
Simple Flow ◽  
Stress Flow

The low-temperature superplastic flow behavior of two lots of Ti-6Al-4V sheet with an ultrafine microstructure was modeled. One lot (Sheet A) had an equiaxed-alpha starting microstructure; the flow stress/flow hardening exhibited by this material was explained on the basis of the Bird-Mukherjee-Dorn constitutive equation. The other material (Sheet B), having a mixed equiaxed- and remnant-lamellar alpha microstructure, underwent flow softening, flow hardening, or steady-state flow depending on test temperature and strain rate. These behaviors were interpreted in the context of a dynamic spheroidization model. The apparent flow softening at the end of all of the flow curves was explained using a simple flow-localization model.

Effect of Crystallographic Orientation on Hardness and Indentation Modulus in Austenitic Stainless Steel

2013 ◽  
Vol 586 ◽  
pp. 31-34 ◽  
Author(s):  
Petr Haušild ◽  
Aleš Materna ◽  
Jiri Nohava
Keyword(s):  
Stainless Steel ◽  
Crystallographic Orientation ◽  
Indentation Test ◽  
Indentation Load ◽  
Indentation Modulus ◽  
Instrumented Indentation ◽  
Depth Of Penetration ◽  
Indentation Method ◽  
Electron Back Scattered Diffraction ◽  
Instrumented Indentation Test

The most commonly used method for the analysis of instrumented indentation test (Oliver-Pharr) is based on isotropic elastic solution of contact problem which is not necessarily valid when indenting at the scale of one (anisotropic) grain. In this paper, we performed the grid indentation method at the sub-micron scale (at low indentation load and depth of penetration) on an area containing several grains with different crystallographic orientation which was simultaneously characterized by electron back-scattered diffraction. Measured dependencies of hardness and indentation modulus on crystallographic orientation were compared with analytical solution and finite element simulations.

Hot Deformation Behavior and Microstructure Evolution of Extruded 6069 Al Alloy under Tension

2014 ◽  
Vol 670-671 ◽  
pp. 33-36
Author(s):  
Horng Yu Wu ◽  
Ming Chieh Lin ◽  
Feng Jun Zhu ◽  
Cheng Tao Wu ◽  
Ching Hao Liao ◽  
...  
Keyword(s):  
Dynamic Recovery ◽  
Flow Behavior ◽  
True Strain ◽  
Peak Stress ◽  
Tensile Tests ◽  
Al Alloy ◽  
Strain Rates ◽  
Flow Curves ◽  
Softening Mechanism ◽  
Dynamic Softening

The flow behavior and associated microstructural changes of wrought 6069 Al alloy deformed in tension were analyzed in this work. Tensile tests were conducted on an extruded tube with a thickness of 1.6 mm in the temperature range of 300–500 oC, with initial strain rates from 0.001 to 0.1 s-1. The true stress–true strain curves exhibited a peak stress at a critical strain. The overall level of the flow curve increased when the strain rate was increased and/or the temperature was decreased. The flow curves exhibited a typical flow behavior with dynamic softening and showed that the softening degree after reaching the peak stress was dependent on the deformation conditions. This could be related to the softening mechanism. The main softening mechanism of the alloy was dynamic recovery (DRV) at low temperatures; dynamic recrystallization (DRX) occurred as deformed at high temperatures.

scholarly journals Estimativa de precipitação e vazões médias para a bacia hidrográfica do rio Itacaiúnas (BHRI), Amazônia Oriental, Brasil (Estimation of Precipitation and average Flows for the Itacaiúnas River Watershed (IRW) - Eastern Amazonia, Brazil)

2017 ◽  
Vol 10 (5) ◽  
pp. 1638 ◽  
Author(s):  
Renato Oliveira Silva Júnior ◽  
Joaquim Carlos Barbosa Queiroz ◽  
Douglas Batista Silva Ferreira ◽  
Alexandra Lima Tavares ◽  
Pedro Walfir Martins Souza-Filho ◽  
...  
Keyword(s):  
Forest Cover ◽  
Flow Behavior ◽  
Climate Prediction ◽  
Reference Station ◽  
Conservation Units ◽  
Flow Curves ◽  
Seasonal Behavior ◽  
Flow Rates ◽  
Single Station ◽  
Climate Prediction Center

Este artigo discute a relação entre dados observados de precipitação de sete estações meteorológicas e os dados resultantes de interpolação realizadas pelo Climate Prediction Center (CPC) para a área da bacia hidrográfica do rio Itacaiúnas (BHRI), Amazônia Oriental, no período de 1986-2005. O trabalho avalia também a aplicação de metodologias expeditas para estimar vazões médias mensais nas sub bacias, a partir de uma única estação de referência situada em seu exutório. As vazões foram estimadas pelos métodos de correção pela área de drenagem e de padronização de vazões médias comparadas com vazões medidas (1985-1995) em uma de suas sub bacias. Os resultados obtidos para a precipitação mostraram-se compatíveis com o comportamento sazonal definido para a região, cuja correlação entre os dados observados e os interpolados pelo CPC demonstram que estes representam bem a variabilidade espaço-temporal da precipitação na BHRI. A análise dos resultados das estações meteorológicas mostrou uma tendência de incremento na precipitação de leste para oeste, cujo comportamento pode estar associado a densa cobertura florestal que compõe o mosaico de Unidades de Conservação (UC’s), combinado com altitudes elevadas (600-800 m) da Serra de Carajás. A avaliação do comportamento das vazões da única estação (Fazenda Alegria) com série de dados fluviométricos disponíveis apresentou resultados consistentes com o comportamento sazonal das curvas de vazão dentro do ano hidrológico. Os métodos utilizados para a estimativa de vazões mostraram resultados diferenciados em termos absolutos, porém, as curvas de vazões estimadas acompanham o comportamento da curva de vazões medidas na estação Fazenda Rio Branco.  A B S T R A C TThis paper discusses the relationship between observed precipitation data from seven meteorological stations and the resulting interpolation data from the Climate Prediction Center (CPC) for the area of the Itacaiúnas river basin (BHRI), Eastern Amazonia, in the period 1986-2005. The work also evaluates the application of expeditious methodologies to estimate monthly average flows in the sub basins, from a single reference station located in its exutorio. The flow rates were estimated by the methods of correction by the drainage area and standardization of average flows compared to measured flows (1985-1995) in one of its sub basins. The results obtained for the precipitation were compatible with the seasonal behavior defined for the region, whose correlation between the data observed and those interpolated by the CPC show that they represent well the spatio-temporal variability of the precipitation in the BHRI. The analysis of the results of the meteorological stations showed a tendency of increase in the precipitation from east to west, whose behavior may be associated with dense forest cover that composes the mosaic of Conservation Units (UC's), combined with high altitudes (600-800 m) of the Serra de Carajás. The evaluation of the flow behavior of the single station (Fazenda Alegria) with a series of available fluviometric data presented results consistent with the seasonal behavior of the flow curves within the hydrological year. The methods used for the estimation of flow rates showed different results in absolute terms, however, the estimated flow curves follow the behavior of the measured flow curve in Fazenda Rio Branco station. Keywords: Estimation, precipitation, flow, sub basin, Eastern Amazon 

scholarly journals Physicochemical Properties of Enzymatically Modified Starches

Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2251
Author(s):  
Abdellatif A. Mohamed ◽  
Husham Alqah ◽  
Mohammed S. Alamri ◽  
Shahzad Hussain ◽  
Akram A. Qasem ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Flow Behavior ◽  
The Other ◽  
Arrhenius Model ◽  
Flow Curves ◽  
Flow Behavior Index ◽  
Excess Water ◽  
Modified Starches ◽  
Water Holding ◽  
Behavior Index

The physicochemical properties of native, annealed and enzyme-treated chickpea (CP), corn (CS), Turkish bean (TB) and sweet potato (SPS) were investigated. Germinated sorghum extract (GSET) was used as the source of enzymes. Starches were annealed in excess water by holding the slurry at 60 °C for 60 min with or without GSET. The flow curves/rheological data were fitted to the power law, Casson and Herschel–Bulkley models. Starches exhibited shear thinning behavior and a variation in the flow behavior index (n) (0.34–0.82) as a function of the starch type. The consistency index (k) of CP and CS decreased with annealing and GSET treatment but increased for TB and SPS. Annealed and GSET-treated SPS exhibited the highest yield stress compared to the other starches, except for CP. The temperature dependency of all starches was well described by the Arrhenius model (r2 = 0.88–0.99). The activation energy (Ea) values were in the range of 660–5359 (J/mol). The TB exhibited the most Ea and SPS the least. With the exception of SPS, annealing appeared to increase the Ea of all tested starches, but the range of Ea was broader for SPS and CS. Annealed and GSET starches exhibited an increase in the gelatinization temperatures (onset and peak) and a decrease in gelatinization enthalpy (ΔH). The syneresis and water holding capacity decreased after annealing or GSET treatment.

Compressive Flow Behavior of AZ61 Mg Alloy at Elevated Temperatures

2011 ◽  
Vol 311-313 ◽  
pp. 587-590
Author(s):  
Horng Yu Wu ◽  
Pin Hou Sun ◽  
Jie Chen Yan ◽  
Jing Hao Liao ◽  
Feng Jun Zhu ◽  
...  
Keyword(s):  
Structural Changes ◽  
Elevated Temperatures ◽  
Flow Behavior ◽  
Mg Alloy ◽  
Strain Rates ◽  
Compression Tests ◽  
Flow Curves ◽  
Hollomon Parameter ◽  
Compressive Flow ◽  
Az61 Mg Alloy

The flow behavior and associated structural changes of an AZ61 Mg alloy were analyzed by using hot compression tests in the temperature and strain rate ranges of 250–400 °C and 0.001 to 1 s–1, respectively. The stress–strain curves exhibited the trend typical of materials in which deformation is recovery-controlled in the high Z regime (Z is the Zener–Hollomon parameter), while at low strain rates and high T, the flow curves exhibited a softening typical of recrystallization phenomena. Microstructure analysis has been performed to correlate the microstructure changes to the flow behaviors.

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