Mechanical Property Evaluation of Electroplated High Aspect Ratio Microstructures

1998 ◽  
Vol 518 ◽  
Author(s):  
L. S. Stephens ◽  
K.W. Kelly ◽  
E.I. Meletis ◽  
S. Simhadri
Keyword(s):  
Mechanical Properties ◽  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Mold Insert ◽  
Processing Parameters ◽  
Strength Properties ◽  
Knoop Hardness ◽  
Modulus Of Rupture ◽  
Mechanical Seal ◽  
Property Evaluation

AbstractHigh aspect ratio microstructures (HARMs) with a height of hundreds of micrometers and a width of a few tens of micrometers present high promise in a number of challenging fields. At LSU, a number of applications are being developed in which nickel HARMs are electroplated on metal surfaces (mold insert fabrication for the LIGA process, HARMs on mechanical seal faces, HARMs on heat exchange surfaces, etc.). In some of these applications, the HARMs are subjected to high stresses and the mechanical properties are particularly important. These properties can be used to adjust processing parameters to optimize properties of the HARMS.This paper presents a method for measuring the strength properties of cantilevered nickel HARMs constructed by LIGA. Experimentally measured values are reported for modulus of rupture (1280 MPa), Young's modulus (153 GPa) and Knoop hardness (500 Hk) for HARMs with an overplated base. SEM micrographs clearly indicate that failure of the beams is brittle and most frequently occurs at the interface of the beam and overplated base.

Functionalization and Tip-open of Carbon Nanotubes for High-Performance Symmetric Supercapacitor

2021 ◽  
Author(s):  
Yaxiong Zhang ◽  
Erqing Xie
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Aspect Ratio ◽  
Specific Surface ◽  
Surface Area ◽  
Chemical Stability ◽  
High Aspect Ratio ◽  
High Performance ◽  
Large Specific Surface Area ◽  
Symmetric Supercapacitor

Carbon nanotubes (CNTs) have been widely studied as supercapacitor electrodes because of their excellent conductivity, high aspect ratio, excellent mechanical properties, chemical stability, and large specific surface area. However, the...

scholarly journals Sixteen properties of Eucalyptus Tereticornis wood for structural uses

2020 ◽  
Vol 36 (2) ◽  
Author(s):  
Marta Cristina de Jesus Albuquerque Nogueira ◽  
Victor Almeida de Araujo ◽  
Juliano Souza Vasconcelos ◽  
André Luis Christoforo ◽  
Francisco Antonio Rocco Lahr
Keyword(s):  
Mechanical Properties ◽  
Decision Making ◽  
Shear Stress ◽  
Modulus Of Elasticity ◽  
Strength Properties ◽  
Modulus Of Rupture ◽  
Eucalyptus Tereticornis ◽  
Moisture Contents ◽  
Through Diffusion ◽  
Standard Documents

Forest Red Gum eucalypt provides a versatile wood and is converted into different purposes. However, such wood is somewhat limited in structural ends, which highlights the need to exploit this gap through diffusion of mechanical properties of such timber. Obtained results should assist engineers and architects in decision-making for its best building application. This paper studied two physical and fourteen mechanical properties evaluation of Eucalyptus tereticornis at two different moisture contents, following the prescriptions of Brazilian (ABNT NBR 7190: 1997) and North American (ASTM D-143-14: 2014) standard documents. Thus, 1091 repeats were carried out for all properties. By a moisture reduction from 30% to 12%, the bulk density and eleven strength properties statistically showed changes such as modulus of rupture (static bending, parallel and perpendicular compressions), modulus of elasticity (perpendicular compression and static bending), shear stress, tangential cleavage, and parallel and perpendicular hardnesses. Then, the Eucalyptus tereticornis timber could be better usable if is further applied for structural construction uses.

scholarly journals Direct Generation of High-Aspect-Ratio Structures of AISI 316L by Laser-Assisted Powder Deposition

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5670
Author(s):  
Piera Alvarez ◽  
M. Ángeles Montealegre ◽  
Francisco Cordovilla ◽  
Ángel García-Beltrán ◽  
Ignacio Angulo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aspect Ratio ◽  
Cross Sections ◽  
High Aspect Ratio ◽  
316L Stainless Steel ◽  
Laser Metal Deposition ◽  
Homogeneous Microstructure ◽  
Tension Tests ◽  
Powder Deposition ◽  
Direct Generation

The effect of process parameters and the orientation of the cladding layer on the mechanical properties of 316L stainless steel components manufactured by laser metal deposition (LMD) was investigated. High aspect-ratio walls were manufactured with layers of a 4.5 mm wide single-cladding track to study the microstructure and mechanical properties along the length and the height of the wall. Samples for the tensile test (according to ASTM E-8M-04) were machined from the wall along both the direction of the layers and the direction perpendicular to them. Cross-sections of the LMD samples were analyzed by optical and scanning electron microscopy (SEM). The orientation of the growing grain was observed. It was associated with the thermal gradient through the building part. A homogeneous microstructure between consecutive layers and some degree of microporosity was observed by SEM. Uniaxial tension tests were performed on samples extracted from the wall in perpendicular and parallel directions. Results for ultimate tensile strength were similar in both cases and with the wrought material. The σ0.2 were similar in both cases but slightly superior to the wrought material.

scholarly journals Strain and Temperature Sensitivities Along with Mechanical Properties of CNT Buckypaper Sensors

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3067
Author(s):  
Shiuh-Chuan Her ◽  
Wei-Chun Hsu
Keyword(s):  
Mechanical Properties ◽  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Complex Surface ◽  
Thermogravimetric Analyzer ◽  
Low Aspect Ratio ◽  
Four Point Bending ◽  
Thermal Chamber ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

In this work, buckypaper composed of multi-walled carbon nanotubes (MWCNT) was prepared through a vacuum filtration process. The effect of MWCNT aspect ratio on the buckypaper performance was investigated. The freestanding and highly flexible buckypaper can be used as a sensor to attach on a complex surface monitoring the strain and temperature at the critical area. The mechanical properties of the buckypaper were examined using the tensile and nanoindentation tests. The strain and temperature sensitivities of the buckypaper were evaluated through the four-point bending and thermal chamber tests, respectively. In addition, the microstructure and thermal stability of the buckypaper were studied by scanning electron microscopy (SEM) and thermogravimetric analyzer (TGA), respectively. Experimental results showed that the mechanical properties such as Young’s modulus, tensile strength, fracture strain, and hardness of the buckypaper made of high aspect ratio MWCNTs were significantly superior to the buckypaper consisted of low aspect ratio MWCNTs, while the strain and temperature sensitivities of the buckypaper composed of low aspect ratio MWCNTs were better than that of the buckypaper made of high aspect ratio MWCNTs.

Mechanical properties of natural rubber nanocomposites reinforced with high aspect ratio cellulose nanocrystals isolated from soy hulls

2016 ◽  
Vol 153 ◽  
pp. 143-152 ◽  
Author(s):  
Wilson Pires Flauzino Neto ◽  
Marcos Mariano ◽  
Ingrid Souza Vieira da Silva ◽  
Hudson Alves Silvério ◽  
Jean-Luc Putaux ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aspect Ratio ◽  
Natural Rubber ◽  
Cellulose Nanocrystals ◽  
High Aspect Ratio ◽  
Soy Hulls ◽  
Rubber Nanocomposites

scholarly journals Mechanically Improved and Multifunctional CFRP Enabled by Resins with High Concentrations Epoxy-Functionalized Fluorographene Fillers

2021 ◽  
Author(s):  
Junhua Wei
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Elastic Modulus ◽  
Carbon Fiber ◽  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Reinforcing Particles ◽  
Thermoset Resin ◽  
High Concentrations ◽  
Carbon Based

To meet the maximum potential of the mechanical properties of carbon fiber reinforced plastics (CFRP), stress transfer between the carbon fibers through the polymer matrix must be improved. A recent promising approach reportedly used reinforcing particles as fillers dispersed in the resin. Carbon based fillers are an excellent candidate for such reinforcing particles due to their intrinsically high mechanical properties, structure and chemical nature similar to carbon fiber and high aspect ratio. They have shown great potential in increasing the strength, elastic modulus and other mechanical properties of interest of CFRPs. However, a percolation threshold of ~1% of the carbon-based particle concentration in the base resin has generally been reported, beyond which the mechanical properties deteriorate due to particle agglomeration. As a result, the potential for further increase of the mechanical properties of CFRPs with carbon-based fillers is limited. We report a significant increase in the strength and elastic modulus of CFRPs, achieved with a novel reinforced thermoset resin that contains high loadings of epoxy-reacted fluorographene (ERFG) fillers. We found that the improvement in mechanical performance of CFRPs was correlated with increase in ERFG loading in the resin. Using a novel thermoset resin containing 10 wt% ERFG filler, CFRPs fabricated by wet layup technique with twill weaves showed a 19.6% and 17.7% increase in the elastic modulus and tensile strength respectively. In addition, because of graphene’s high thermal conductivity and high aspect ratio, the novel resin enhanced CFRPs possessed 59.3% higher through-plane thermal conductivity and an 81-fold reduction in the hydrogen permeability. The results of this study demonstrate that high loadings of functionalized particles dispersed in the resin is a viable path towards fabrication of improved, high-performance CFRP parts and systems.

scholarly journals VARIABILITY OF SOME MECHANICAL PROPERTIES OF SAN RAMON TALL VARIETY OF COCONUT

CORD ◽  
1994 ◽  
Vol 10 (01) ◽  
pp. 34
Author(s):  
R. N. Palomar
Keyword(s):  
Mechanical Properties ◽  
Natural Variation ◽  
Elastic Limit ◽  
Strength Properties ◽  
Modulus Of Rupture ◽  
Average Moisture Content ◽  
Rupture Stress ◽  
Crushing Strength ◽  
The Core ◽  
Strength In Compression

The natural variation of some strength properties of about 80‑year old brown‑and green‑pigmented San Ramon variety of coconut was investigated. The properties were determined from tests on small clear specimens in the air dry condition with an average moisture content of 16.98%. The mechanical properties studied include modulus of rupture, stress at elastic limit and modulus of elasticity in static bending, maximum crushing strength in compression parallel to grain, stress at elastic limit and in compression perpendicular to grain, and shear parallel to grain.   The brown‑pigmented trees showed significantly higher values in all the mechanical properties than the green‑pigmented palms.   For the brown‑and green‑pigmented trees, the values of strength properties markedly decreased with increasing height levels and significantly increased radially from the core to the periphery of the stem.

Sign in / Sign up

Export Citation Format

Share Document