Mechanical Properties Evolution of Polydimethylsiloxane During Crosslinking Process

2006 ◽  
Vol 975 ◽  
Author(s):  
Yi Zhao ◽  
Xin Zhang
Keyword(s):  
Mechanical Properties ◽  
Mechanical Behavior ◽  
Measurement System ◽  
Curing Agent ◽  
Operational Parameters ◽  
Crosslinking Process ◽  
Sensing Applications ◽  
Curvature Measurement ◽  
The Relationship ◽  
Mechanical Sensing

ABSTRACTThis paper reports mechanical properties evolution of polydimethylsiloxane (PDMS) during the crosslinking process. In this work, PDMS crosslinking was induced by mixing base prepolymer and curing agent at certain ratios. The liquid prepolymer was spun coated on a silicon wafer, and the curvature change of the wafer was measured continuously using a curvature measurement system. The relationship between the curvature change and typical mechanical properties was investigated using a bilayer model; and the evolution of the properties was derived, as a function of operational parameters. This work is expected to help better understanding of the crosslinking process and provide practical strategies for controlling the mechanical behavior of the resulting polymer structures, especially those for mechanical sensing applications.

Stress Hysteresis and Thermal-Mechanical Behavior of PECVD Silicon Nitride and Ebeam Aluminum Films for Microbolometer Applications

2004 ◽  
Vol 854 ◽  
Author(s):  
Shusen Huang ◽  
Xin Zhang
Keyword(s):  
Silicon Nitride ◽  
Mechanical Behavior ◽  
Measurement System ◽  
Low Cost ◽  
High Sensitivity ◽  
Central Idea ◽  
Aluminum Films ◽  
Uncooled Microbolometer ◽  
Curvature Measurement ◽  
Stress Hysteresis

ABSTRACTUncooled cantilever-based microbolometer arrays received more attention recently due to high sensitivity and low cost. The central idea is built on the deflection of a bilayer SiNx/Al material upon the temperature change. The thermal-mechanical behavior of the bilayer is significant for the performance of the microbolometers. In this paper, we perform thermal cyclings to aluminum and SiNx films. The CTEs and the stress evolutions were measured using a curvature measurement system. The curvature profile of a SiNx/Al/Si component was predicted using an extension of Stoney's formula, well agreeing with the experimental results. This work demonstrates fundamental mechanics issues in bilayer SiNx/Al components, which have a great potential for the use in uncooled microbolometer applications.

scholarly journals Development of Polypropylene/Polyethylene Terephthalate Microfibrillar Composites Filament to Support Waste Management

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 233 ◽  
Author(s):  
Abdulhakim Almajid ◽  
Rolf Walter ◽  
Tim Kroos ◽  
Harry Junaidi ◽  
Martin Gurka ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Waste Management ◽  
Mechanical Behavior ◽  
Polyethylene Terephthalate ◽  
Melt Temperature ◽  
Chamber Temperature ◽  
Microfibrillar Composites ◽  
Stretching Ratio ◽  
The Relationship ◽  
Properties Of Composites

The concept of microfibrillar composites (MFCs) is adopted to produce composites of polyethylene terephthalate (PET) fiber-reinforced polypropylene (PP) materials. The two polymers were dry mixed with PET content ranging from 22 to 45 wt%. The PET has been used as a reinforcement to improve the mechanical properties of composites. The relationship between the morphology of the MFC structure and the mechanical behavior of the MFC filament was investigated. Analysis of the structure and mechanical behavior helped to understand the influence of the stretching ratio, extruder-melt temperature, stretching-chamber temperature, and filament speed.

scholarly journals Crystal structure, hydrogen bonding, mechanical properties and Raman spectrum of the lead uranyl silicate monohydrate mineral kasolite

RSC Advances ◽  
2019 ◽  
Vol 9 (27) ◽  
pp. 15323-15334 ◽  
Author(s):  
Francisco Colmenero ◽  
Jakub Plášil ◽  
Joaquín Cobos ◽  
Jiří Sejkora ◽  
Vicente Timón ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Mechanical Properties ◽  
Hydrogen Bonding ◽  
Raman Spectrum ◽  
Mechanical Behavior ◽  
New Method ◽  
Complex Crystal Structure ◽  
Detailed Interpretation ◽  
The Relationship ◽  
Complex Crystal

A profound understanding of the relationship between the complex crystal structure of kasolite and its mechanical behavior is provided. A detailed interpretation of its Raman spectrum and a new method for band resolution are reported.

Modeling of Mechanical Behavior of Porous Sintered Timing Wheel in Contact with Chain Wheels

2007 ◽  
Vol 561-565 ◽  
pp. 1649-1652
Author(s):  
M. Alizadeh ◽  
H. Khorsand ◽  
Ali Shokuhfar
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Finite Element ◽  
Tensile Strength ◽  
Mechanical Behavior ◽  
Sintered Density ◽  
Fem Model ◽  
Gear Contact ◽  
The Relationship ◽  
Good Agreement

The mechanical properties of sintered timing wheel in contact with chain wheels were analysed using Finite Element Methods (FEM), in which the timing wheel is modelled as a metal powder. The mechanical properties of sintered timing wheel were investigated as a function of sintered density. Tensile strength and Young’s modulus increased with a decrease in porosity. Current methods of calculating gear contact stresses use Hertz’s equations, which were originally derived for contact between sintered timing wheel and chain wheels. The results of the 2D dimensional FEM analyses from ANSYS are presented. The relationship between relative density of P/M steels and mechanical behavior is also obtained from FEM and compared with the experimental data. Good agreement between the experimental and FEM results is observed, which demonstrates that FEM can capture the major features of the P/M steels behaviour during loading. This indicates that the FEM model is accurate.

scholarly journals Impedance of tissue-mimicking phantom material under compression

2019 ◽  
Vol 4 (1) ◽  
pp. 2-12 ◽  
Author(s):  
Barry Belmont ◽  
Robert E. Dodde ◽  
Albert J. Shih
Keyword(s):  
Mechanical Properties ◽  
Electrical Properties ◽  
Soft Tissue ◽  
Porous Structure ◽  
Mechanical Behavior ◽  
Biological Tissues ◽  
Stress And Strain ◽  
The Relationship ◽  
Passive Electrical Properties ◽  
Phantom Material

Abstract The bioimpedance of tissues under compression is a field in need of study. While biological tissues can become compressed in a myriad of ways, very few experiments have been conducted to describe the relationship between the passive electrical properties of a material (impedance/admittance) and its underlying mechanical properties (stress and strain) during deformation. Of the investigations that have been conducted, the exodus of fluid from samples under compression has been thought to be the cause of changes in impedance, though until now was not measured directly. Using a soft tissue-mimicking phantom material (tofu) whose passive electrical properties are a function of the conducting fluid held within its porous structure, we have shown that the mechanical behavior of a sample under compression can be measured through bioimpedance techniques.

scholarly journals Extraction of Anisotropic Mechanical Properties From Nanoindentation of SiC-6H Single Crystals

2016 ◽  
Vol 83 (9) ◽  
Author(s):  
Amit Datye ◽  
Lin Li ◽  
Wei Zhang ◽  
Yujie Wei ◽  
Yanfei Gao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Mechanical Behavior ◽  
Peak Load ◽  
Contact Analysis ◽  
Elastic Contact ◽  
Wide Range ◽  
Anisotropic Mechanical Properties ◽  
Anisotropic Elastic ◽  
The Relationship

Because brittle solids fail catastrophically during normal tension and compression testing, nanoindentation is often a useful alternative technique for measuring their mechanical properties and assessing their deformation characteristics. One practical question to be addressed in such studies is the relationship between the anisotropy in the uniaxial mechanical behavior to that in the indentation response. To this end, a systematic study of the mechanical behavior the 6H polytype of a hexagonal silicon carbide single crystal (SiC-6H) was performed using standard nanoindentation methods. The indentation elastic modulus and hardness measured using a Berkovich indenter at a peak load of 500 mN varied over a wide range of crystal orientation by only a few percent. The variation in modulus is shown to be consistent with an anisotropic elastic contact analysis based on the known single crystal elastic constants of the material. The variation in hardness is examined using a single crystal plasticity model that considers the anisotropy of slip in hexagonal crystals. When compared to experimental measurements, the analysis confirms that plasticity in SiC-6H is dominated by basal slip. An anisotropic elastic contact analysis provides insights into the relationship between the pop-in load, which characterizes the transition from elasticity to plasticity during nanoindentation testing, and the theoretical strength of the material. The observations and analyses lay the foundations for further examination of the deformation and failure mechanisms in anisotropic materials by nanoindentation techniques.

MODELISATION DE L'INFLUENCE DU TRAITEMENT THERMIQUE SUR LES PROPRIETES MECANIQUES DES ALLIAGES ALUMINIUM-CUIVRE (Al-Cu)

2015 ◽  
Vol 10 (2) ◽  
pp. 2753-2761
Author(s):  
Saad El Madani ◽  
S. ELHAMZI ◽  
A. IBNLFASSI ◽  
L. ZERROUK ◽  
O. BEN LENDA ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Behavior ◽  
Solidification Process ◽  
Traitement Thermique ◽  
Homogenization Process ◽  
Fundamental Reason ◽  
Segregation Phenomenon ◽  
Proprietes Mecaniques ◽  
Cooling Velocity ◽  
Copper Effect

In order to master and improve the quality and properties of the final products, the major industrial challenge lies in the possibility of controlling the morphology, size of microstructures that reside within the molded pieces, as well as their defects; this is the fundamental reason according to which we are more and more interested in mastering the growth and germination of such alloys, as well as the developing structures, at the time of solidification process. The modeling reveals as a valuable aid in the mastery of the formation of such heterogeneousness: segregation cells that are incompatible with industrial requirements.   The whole work focuses upon the modeling of the segregation phenomenon of the four hypoeutectic alloys, Al1%Cu, Al2%Cu, Al3%Cu et Al4%Cu, as well as the copper effect upon certain mechanical properties of aluminum. Usually, the microstructure and mechanical behavior of such alloys as Al-Cu are directly influenced by some parameters such as composition, cooling velocity and homogenization process.

Sunlight exposure: the effects on the performance of paragliding fabric

2018 ◽  
Vol 69 (05) ◽  
pp. 381-389
Author(s):  
MENGÜÇ GAMZE SÜPÜREN ◽  
TEMEL EMRAH ◽  
BOZDOĞAN FARUK
Keyword(s):  
Mechanical Properties ◽  
Aging Process ◽  
Air Permeability ◽  
Sunlight Exposure ◽  
Test Results ◽  
Coating Materials ◽  
Strength Tests ◽  
Before And After ◽  
The Relationship ◽  
Dark Blue

This study was designed to explore the relationship between sunlight exposure and the mechanical properties of paragliding fabrics which have different colors, densities, yarn counts, and coating materials. This study exposed 5 different colors of paragliding fabrics (red, turquoise, dark blue, orange, and white) to intense sunlight for 150 hours during the summer from 9:00 a.m. to 3:00 p.m. for 5 days a week for 5 weeks. Before and after the UV radiation aging process, the air permeability, tensile strength, tear strength, and bursting strength tests were performed. Test results were also evaluated using statistical methods. According to the results, the fading of the turquoise fabric was found to be the highest among the studied fabrics. It was determined that there is a significant decrease in the mechanical properties of the fabrics after sunlight exposure. After aging, the fabrics become considerably weaker in the case of mechanical properties due to the degradation in both the dyestuff and macromolecular structure of the fiber

Comparison of different curing method for mechanical properties of self-curing agent using diapers polymer

2021 ◽  
Author(s):  
Daud Mohamad ◽  
Salmia Beddu ◽  
Ibrahim ◽  
Karim Sherif ◽  
Mahyun Zainoddin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Curing Agent ◽  
Curing Method

scholarly journals Water lubrication of graphene oxide-based materials

Friction ◽  
2021 ◽  
Author(s):  
Shaoqing Xue ◽  
Hanglin Li ◽  
Yumei Guo ◽  
Baohua Zhang ◽  
Jiusheng Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Lubrication Theory ◽  
Lubricant Additives ◽  
Water Lubrication ◽  
Broad Application ◽  
Water Dispersibility ◽  
Metal Processing ◽  
The Relationship ◽  
Ph Concentration

AbstractWater is as an economic, eco-friendly, and efficient lubricant that has gained widespread attention for manufacturing. Using graphene oxide (GO)-based materials can improve the lubricant efficacy of water lubrication due to their outstanding mechanical properties, water dispersibility, and broad application scenarios. In this review, we offer a brief introduction about the background of water lubrication and GO. Subsequently, the synthesis, structure, and lubrication theory of GO are analyzed. Particular attention is focused on the relationship between pH, concentration, and lubrication efficacy when discussing the tribology behaviors of pristine GO. By compounding or reacting GO with various modifiers, amounts of GO-composites are synthesized and applied as lubricant additives or into frictional pairs for different usage scenarios. These various strategies of GO-composite generate interesting effects on the tribology behaviors. Several application cases of GO-based materials are described in water lubrication, including metal processing and bio-lubrication. The advantages and drawbacks of GO-composites are then discussed. The development of GO-based materials for water lubrication is described including some challenges.

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