Evaluation of Mechanical Strength of Miniaturized Functional Substrates and Components in Different Environments

2016 ◽  
Vol 13 (1) ◽  
pp. 17-22
Author(s):  
Raul Bermejo ◽  
Clemens Krautgasser ◽  
Marco Deluca ◽  
Martin Pletz ◽  
Peter Supancic ◽  
...  
Keyword(s):  
Environmental Degradation ◽  
Protective Layer ◽  
Strength Distribution ◽  
Rectangular Plates ◽  
Biaxial Testing ◽  
Surface Features ◽  
Silicon Chips ◽  
Ceramic Components ◽  
Experimental Findings ◽  
Functional Components

Functional components such as multilayer, low-temperature cofired ceramics are examples of the combination of a ceramic-based substrate with internal electrodes as well as surface features (e.g., metallization, contacting pads, and cylindrical vias) employed to provide the component with a given functionality. Another example is that of functionalized silicon chips to be embedded into polymer circuit boards to enhance integration and save costs. The functionality of the system can be influenced by the mechanical reliability of the different components. Due to miniaturization and design complexity, no standard methods for mechanical testing can be applied for the characterization of these brittle components. In this work, an experimental approach is presented that enables the determination of the strength distribution in functional components (e.g., rectangular plates as small as 2 ×2 ×0.12 mm3) in different environments at different temperatures. The method is based on localized biaxial testing using a ball-on-three-balls fixture. The high accuracy of the test allows quantification of the effect of surface quality, surface features, and/or metallization (e.g., contact pads or cylindrical vias) on the component strength distribution. Experimental findings show that the strength distribution of ceramic components can be affected by environmental degradation, whereby subcritical crack growth phenomena can be enhanced in environments with high relative humidity. In addition, metallization at the surface subjected to tensile stresses can even raise the strength of the component, acting as a protective layer against environmental degradation, whereas cylindrical vias can become weak points in the design. It is shown that functionalized layers such as those used in silicon chips can have a significant effect on the strength parameters, thus influencing the lifetime of the device.

Mechanical characterization of miniaturized functional substrates and components in different environments

2015 ◽  
Vol 2015 (CICMT) ◽  
pp. 000085-000091
Author(s):  
Raul Bermejo ◽  
Clemens Krautgasser ◽  
Marco Deluca ◽  
Martin Pletz ◽  
Peter Supancic ◽  
...  
Keyword(s):  
Environmental Degradation ◽  
Protective Layer ◽  
Strength Distribution ◽  
Rectangular Plates ◽  
Biaxial Testing ◽  
Surface Features ◽  
Silicon Chips ◽  
Experimental Findings ◽  
Functional Components

Functional components such as multilayer low temperature co-fired ceramics are examples of the combination of a ceramic-based substrate with internal electrodes as well as surface features (e.g. metallization, contacting pads, cylindrical vias, etc) employed to provide the component with a given functionality. Another example is that of functionalized silicon chips to be embedded into polymer circuit boards in order to enhance integration and save costs. The functionality of the system can be influenced by the mechanical reliability of the different components. Due to miniaturization and design complexity, no standard methods for mechanical testing can be applied for the characterization of these brittle components. In this work, an experimental approach is presented, which enables determining the strength distribution in functional components (e.g. rectangular plates as small as 2 × 2 × 0.1 mm3) in different environments at different temperatures. The method is based on localized biaxial testing using a ball-on-three-balls fixture. The high accuracy of the test allows quantifying the effect of surface quality, surface features and/or metallization (e.g. contact pads or cylindrical vias) on the component strength distribution. Experimental findings show that the strength distribution of ceramic components can be affected by environmental degradation, whereby subcritical crack growth phenomena can be enhanced in environments with high relative humidity. In addition, metallization at the surface subjected to tensile stresses can even raise the strength of the component, acting as a protective layer against environmental degradation, whereas cylindrical vias can become weak points in the design. It is shown that functionalized layers such as those used in silicon chips can have a significant effect on the strength parameters, thus influencing the lifetime of the device.

scholarly journals Chemical Durability of Glass Containing Srp Waste - Leachability Characteristics, Protective Layer Formation, and Repository System Interactions

1981 ◽  
Vol 11 ◽  
Author(s):  
George G. Wicks ◽  
Barbara M. Robnett ◽  
W. Duncan Rankin
Keyword(s):  
Protective Layer ◽  
Layer Formation ◽  
Surface Layers ◽  
Waste Products ◽  
Safety And Reliability ◽  
Experimental Findings ◽  
Nuclear Waste Forms ◽  
Leaching Models ◽  
Surface Layer Formation

Leachability is one of the most important properties of solidified nuclear waste forms because it provides information on the performance and the subsequent safety and reliability that the waste products will possess. One of the most important experimental findings in the leachability field has been the discovery and subsequent detailed characterization of protective surface layers that form on waste glass during leaching. These layers can have a beneficial effect on product performance while in storage by improving productdurability with time. As a result of surface layer formation and the effects on subsequent product leaching characteristics, new qualitative and quantitative leaching models have recently been proposed.

scholarly journals Thiocarbohydrazones Based on Adamantane and Ferrocene as Efficient Corrosion Inhibitors for Hydrochloric Acid Pickling of C-Steel

Coatings ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1068
Author(s):  
Abdelwahed R. Sayed ◽  
Hany M. Abd El-Lateef
Keyword(s):  
Density Functional ◽  
Corrosion Inhibitors ◽  
Physical Adsorption ◽  
Protective Layer ◽  
Open Circuit ◽  
Organometallic Complexes ◽  
Important Idea ◽  
Eis Measurements ◽  
Inhibition Performance ◽  
Experimental Findings

N′-(adamantan-2-ylidene)hydrazinecarbothiohydrazide and 2-(ferrocenyl-1-ylidene) hydrazinecarbothiohydrazide are used in coordination and organometallic complexes. The important idea of the research in this paper is the principal to prepare thiocarbohydrazones from the reaction of 2-acetylferrocene (Fe-Th) or 2-adamantanone (Ad-Th) with carbonothioic dihydrazide. The materials were elucidated by elemental analysis and spectral data. The as-prepared compounds were applied as effective corrosion inhibitors for HCl pickling of C-steel. Detailed investigations on electrochemical (open circuit potential (OCP) vs. time, potentiodynamic polarization (PDP), and impedance spectroscopy (EIS)) techniques and surface morphology studies are introduced in this work. Results indicated that Fe-Th could deliver greater inhibition performance than Ad-Th, and the highest protection capacity values of 93.6% (Ad-Th) and 97.9% (Fe-Th) were accomplished at 200 ppm. The adsorption of Ad-Th or Fe-Th additives followed the Langmuir isotherm with both the chemical and the physical adsorption with chemisorption predominance. EIS measurements supported a betterment in the capacitive behavior with the corrosion inhibitors. The inhibitors exhibited a mixed-type behavior as observed from the PDP studies. Field emission scanning electron microscopy (FESEM) and Fourier-transform infrared spectroscopy (FTIR) studies emphasize the occurrence of a protective layer of the as-synthesized organic inhibitors on the C-steel interface. Theoretical studies (density functional theory (DFT) calculations and Monte Carlo (MC) simulations) provide appropriate support for the experimental findings. The existing report provides very significant consequences in formulating and designing novel thiocarbohydrazone inhibitors with high protection efficacy.

scholarly journals SCARE: A Postprocessor Program to MSC/NASTRAN for Reliability Analysis of Structural Ceramic Components

1986 ◽  
Vol 108 (3) ◽  
pp. 540-546 ◽  
Author(s):  
J. P. Gyekenyesi
Keyword(s):  
Least Squares Method ◽  
Three Dimensional ◽  
Strain Energy Release ◽  
Maximum Tensile Stress ◽  
Strength Distribution ◽  
Modulus Of Rupture ◽  
Distribution Model ◽  
Mixed Mode Fracture ◽  
Ceramic Components ◽  
Fast Fracture

A computer program is developed for calculating the statistical fast fracture reliability and failure probability of ceramic components. The program includes the two-parameter Weibull material fracture strength distribution model, using the principle of independent action for polyaxial stress states and Batdorf’s shear-sensitive as well as shear-insensitive crack theories, all for volume distributed flaws in macroscopically isotropic solids. Both penny-shaped cracks and Griffith cracks are included in the Batdorf shear-sensitive crack response calculations, using Griffith’s maximum tensile stress or critical coplanar strain energy release rate criteria to predict mixed mode fracture. Weibull material parameters can also be calculated from modulus of rupture bar tests, using the least-squares method with known specimen geometry and fracture data. The reliability prediction analysis uses MSC/NASTRAN stress, temperature, and volume output, obtained from the use of three-dimensional, quadratic, isoparametric, or axisymmetric finite elements. The statistical fast fracture theories employed, along with selected input and output formats and options, are summarized. A sample problem to demonstrate various features of the program is included.

scholarly journals Study of Corrosion Behavior of N’-(2-(2-oxomethylpyrrol-1-yl)ethyl)piperidine for Mild Steel in the Acid Environment

2021 ◽  
Vol 12 (3) ◽  
pp. 3638-3646
Keyword(s):  
Electron Microscopy ◽  
Mild Steel ◽  
Steel Surface ◽  
Inhibition Efficiency ◽  
Protective Layer ◽  
Solution Temperature ◽  
Inhibitor Concentration ◽  
Acid Environment ◽  
Experimental Findings ◽  
Scanning Electron

The corrosion inhibition of mild steel in 1 M hydrochloric acid solution by N'-(2-(2-oxomethylpyrrol-1-yl)ethyl)piperidine (N-OPEP) was studied employing weight loss techniques. The experimental findings revealed that N-OPEP is the most excellent corrosion inhibitor, and the inhibitory performance increases with an increase in the inhibitor concentration. Furthermore, the inhibition efficiency decreases with an increase in the solution Temperature. The adsorption of inhibitor molecules on a mild steel surface followed Langmuir’s isotherm model and was found to be spontaneous. Scanning electron microscopy (SEM) photographs approved the formation of a protective layer of the inhibitor molecules on the surface of mild steel.

Modeling of Threshold Strength in Cylindrical Ceramic Structures

2005 ◽  
Vol 72 (3) ◽  
pp. 381-388 ◽  
Author(s):  
Fjo´la Jo´nsdo´ttir ◽  
Glenn E. Beltz ◽  
Robert M. McMeeking
Keyword(s):  
Ceramic Body ◽  
Three Dimensional ◽  
Element Model ◽  
Ceramic Composites ◽  
Strength Distribution ◽  
Penny Shaped Crack ◽  
Ceramic Components ◽  
Threshold Strength ◽  
Shaped Crack ◽  
Residual Compression

Recently, three-dimensional structured ceramic composites with large threshold strengths (i.e., stress below which there is zero probability of failure) have been fabricated utilizing an architecture consisting of relatively stress-free, elongated prismatic domains, separated by thin compressive walls. We build upon prior work on laminate architectures, with the common feature that these structures are all susceptible to fracture. Typically, these three-dimensional structures consist of thin shells of mullite that surround alumina. Cracks, originating from large flaws within the ceramic body, are arrested by the surrounding compressive layers until a specific stress level is attained (i.e., the threshold strength), resulting in a truncation of the strength distribution in the flaw region. A preliminary stress intensity solution has shown that this arrest is caused by a reduction of the crack driving force by the residual compression in the compressive walls. This solution also predicts that the threshold strength is dependent not only on the magnitude of the residual compression in the walls but also on the dimensions of both phases. A finite element model is presented that utilizes a penny-shaped crack in the interior of such a structure or half-penny-shaped crack emanating from the edge of such a structure. Ongoing analytical and experimental work that is needed to more fully understand this arrest phenomenon and its application towards the development of reliable, damage-tolerant ceramic components are discussed.

scholarly journals Special Issue: Perovskite Nanostructures: From Material Design to Applications

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 97
Author(s):  
Athanasia Kostopoulou ◽  
Dimitra Vernardou
Keyword(s):  
Low Cost ◽  
Material Design ◽  
Charge Carrier Mobility ◽  
Growth Conditions ◽  
Critical Parameters ◽  
Special Issue ◽  
Light Emitting ◽  
Reduced Dimensions ◽  
Experimental Findings ◽  
Functional Components

In the past decade, perovskite materials have attracted great scientific and technological interest due to their interesting opto-electronic properties. Nanostructuring of the perovskites, due to their reduced dimensions are advantageous in offering large surface area, controlled transport and charge carrier mobility, strong absorption and photoluminescence, and confinement effects. These features, together with the unique tunability in composition, shape, and functionalities in addition to the ability to form efficient, low-cost, and light-active structures make the perovskite nanostructures efficient functional components for multiple applications, ranging from photovoltaics and batteries to lasing and light-emitting diodes. The purpose of this Special Issue is to give an overview of the latest experimental findings concerning the tunability in composition, shape, functionalities, growth conditions, and synthesis procedures of perovskite structures and to identify the critical parameters for producing materials with functional characteristics.

scholarly journals Ionic mechanisms and Ca2+ dynamics underlying the glucose response of pancreatic β cells: a simulation study

2011 ◽  
Vol 138 (1) ◽  
pp. 21-37 ◽  
Author(s):  
Chae Young Cha ◽  
Yasuhiko Nakamura ◽  
Yukiko Himeno ◽  
JianWu Wang ◽  
Shinpei Fujimoto ◽  
...  
Keyword(s):  
Action Potentials ◽  
Cell Model ◽  
Repetitive Firing ◽  
Glucose Response ◽  
Slow Potential ◽  
Ionic Mechanisms ◽  
K Current ◽  
Experimental Findings ◽  
Functional Components

To clarify the mechanisms underlying the pancreatic β-cell response to varying glucose concentrations ([G]), electrophysiological findings were integrated into a mathematical cell model. The Ca2+ dynamics of the endoplasmic reticulum (ER) were also improved. The model was validated by demonstrating quiescent potential, burst–interburst electrical events accompanied by Ca2+ transients, and continuous firing of action potentials over [G] ranges of 0–6, 7–18, and >19 mM, respectively. These responses to glucose were completely reversible. The action potential, input impedance, and Ca2+ transients were in good agreement with experimental measurements. The ionic mechanisms underlying the burst–interburst rhythm were investigated by lead potential analysis, which quantified the contributions of individual current components. This analysis demonstrated that slow potential changes during the interburst period were attributable to modifications of ion channels or transporters by intracellular ions and/or metabolites to different degrees depending on [G]. The predominant role of adenosine triphosphate–sensitive K+ current in switching on and off the repetitive firing of action potentials at 8 mM [G] was taken over at a higher [G] by Ca2+- or Na+-dependent currents, which were generated by the plasma membrane Ca2+ pump, Na+/K+ pump, Na+/Ca2+ exchanger, and TRPM channel. Accumulation and release of Ca2+ by the ER also had a strong influence on the slow electrical rhythm. We conclude that the present mathematical model is useful for quantifying the role of individual functional components in the whole cell responses based on experimental findings.

scholarly journals Thermal Shock Analysis and Testing of Simulated Ceramic Components for Gas Turbine Applications

1995 ◽  
Author(s):  
Harindra Rajiyah ◽  
Louis P. Inzinna ◽  
Gerald G. Trantina ◽  
Robert M. Orenstein ◽  
Martin B. Cutrone
Keyword(s):  
Thermal Shock ◽  
Gas Turbine ◽  
Failure Modes ◽  
Failure Prediction ◽  
Rectangular Plates ◽  
Shock Testing ◽  
Multiple Data ◽  
Ceramic Components ◽  
Transient Thermal ◽  
Data Censoring

A ceramic gas seal for a utility gas turbine was designed and analyzed using ANSYS and CARES/LIFE. SN-88 silicon nitride was selected as the candidate material. The objective was to validate the failure prediction methodology using rectangular plates which were thermally shocked in a fluidized bed. The failure prediction methodology would then be applied to the representative component geometry. Refined ANSYS finite element modeling of both the plate and component geometries was undertaken. The CARES/LIFE reliability analysis of the component geometry for fast fracture was performed for two cases: I) steady-state thermo-mechanical loads during normal gas turbine operation and II) transient thermal shock loading during a turbine trip. Thermal shock testing of alumina disks were performed in order to gain confidence in the testing and analysis procedures. Both notched and unnotched SN88 plates were then tested. Failure modes were identified through flexure tests and data censoring was performed using SAS. Weibull modulus was assumed to be invariant with temperature and the scale parameter was assumed to vary through a scaling variable such that multiple data could be pooled.

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