Thermal and mechanical characterization of high performance epoxy systems with extended cure times

1996 ◽  
Vol 46 (6) ◽  
pp. 1511-1525 ◽  
Author(s):  
D. Chinn ◽  
Sang -Beom Shim ◽  
J. C. Seferis
Keyword(s):  
High Performance ◽  
Mechanical Characterization ◽  
Epoxy Systems

Mechanical Characterization Study of Sintered Silver Pastes Bonded in a Double-Lap Configuration

2018 ◽  
Author(s):  
Paul Paret ◽  
Joshua Major ◽  
Douglas DeVoto ◽  
Sreekant Narumanchi ◽  
Yansong Tan ◽  
...  
Keyword(s):  
High Performance ◽  
Mechanical Characterization ◽  
Wide Bandgap ◽  
State University ◽  
Silver Particles ◽  
Enabling Technology ◽  
Characterization Study ◽  
Synthesis Procedure ◽  
Sintered Silver

Sintered silver-based bonded interfaces are a critical enabling technology for high-temperature, compact, high-performance, and reliable wide-bandgap packages and components. High-pressure (∼40 MPa) sintered silver interfaces have been implemented commercially, most notably the commercial products offered by Semikron. To reduce manufacturing complexity, there is significant industry interest in pressure-less sintered silver interfaces. To this end, current formulations of sintered silver paste are comprised of purely nano-sized silver particles or a combination of nano- and micro-sized silver particles/flakes. It is essential to quantify the mechanical properties and determine the reliability of these interfaces prior to use in automotive power electronics applications. In this paper, research efforts at the National Renewable Energy Laboratory, in collaboration with Virginia Polytechnic Institute and State University and an industry partner, in optimizing the synthesis procedure and mechanical characterization of sintered silver double-lap samples are described. These double-lap samples were synthesized using pressure-less sintering techniques. Shear testing was conducted at multiple temperatures and displacement rates on these samples sintered using two types of sintered sintered silver pastes, one of them consisting of nano-silver particles and the other a hybrid paste or a combination of nano- and micron-sized silver flakes, employed in a double-lap configuration. Maximum values of shear stress obtained from the characterization study are reported.

An Alternative Approach for FRCM Matrix Tensile Strength Evaluation

2019 ◽  
Vol 817 ◽  
pp. 365-370 ◽  
Author(s):  
Alessandro Bellini ◽  
Marco Bovo ◽  
Andrea Incerti ◽  
Claudio Mazzotti
Keyword(s):  
Tensile Strength ◽  
High Performance ◽  
Mechanical Characterization ◽  
Experimental Tests ◽  
Tensile Tests ◽  
Test Methods ◽  
Test Method ◽  
The Matrix ◽  
Flexural Tests

Structural retrofitting with composite materials proved to be an effective technique for rehabilitation of degraded or damaged masonry and concrete buildings. Nowadays, Fiber Reinforced Cementitious Matrix (FRCM) composites are widely used as externally bonded strengthening systems thanks to their high performance, low weight and easiness of installation. Several experimental tests and numerical studies are currently available concerning the tensile and bond behavior of FRCM systems, but a debated and still open issue concerns the methods for the mechanical characterization of the mortar used as matrix within the strengthening system. The present paper analyses and compares different test methods for determining the matrix tensile strength. Pure tensile and flexural tests have been carried out on different mortar matrix samples. In order to evaluate which is the most suitable value to be considered for a correct interpretation and modeling of the composite system, the experimental results obtained through flexural tests on standard mortar specimens have been compared with the outcomes obtained from direct tensile tests on FRCM coupons. The present study represents only a first step for the definition of the most appropriate test method for the mechanical characterization of the matrix used within FRCM strengthening systems.

Mechanical Characterization of Graphite and CNT Reinforced Aluminium-5083

2017 ◽  
Vol 889 ◽  
pp. 56-62 ◽  
Author(s):  
D.S. Robinson Smart ◽  
Nithin P. Johns ◽  
Joses Jenish Smart
Keyword(s):  
Corrosion Resistance ◽  
Base Metal ◽  
High Performance ◽  
Mechanical Characterization ◽  
Stir Casting ◽  
Mechanical Tests ◽  
Primary Objective ◽  
Aluminium Metal

Aluminium composites are widely used in a variety of applications including aerospace, automotive, defence, thermal as well as in sports and avocation. Technological and industrial demands often account to inculcating special properties to materials to achieve its target that may not be achieved by conventional materials. This phenomenon was widely observed in the recent decades in fields of aerospace and transport where high performance materials with low densities are required. The primary objective of this work is to develop an Aluminium Metal Matrix Composite (AMMC) by in-situ stir casting for naval applications and successfully bring about self-lubrication properties, thereby lowering wear rate and improving corrosion resistance. This is done by adding graphite at various weight fractions to the base metal. The fabricated composites are subjected to various mechanical tests and corrosion test. It was found that ,increase in graphite addition improves the Microhardness of the material, improves the wear resistance and enhances its corrosion resistance. The materials were further observed and found that , there will be lower tensile strengths compared to the base metal with increase in addition of graphite particles.

Preparation and Characterization of NH2-Terminal Fibrinogen Bβ Fragments from N-DSK of Human Fibrinogen

1984 ◽  
Vol 51 (01) ◽  
pp. 016-021 ◽  
Author(s):  
S Birken ◽  
G Agosto ◽  
B Lahiri ◽  
R Canfield
Keyword(s):  
High Performance ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Reverse Phase ◽  
Human Fibrinogen ◽  
Human Volunteers ◽  
Cnbr Cleavage ◽  
Two Peaks

SummaryIn order to investigate the early release of NH2-terminal plasmic fragments from the Bβ chain of fibrinogen, substantial quantities of Bβ 1-42 and Bβ 1-21 are required as immunogens, as radioimmunoassay standards and for infusion into human volunteers to determine the half-lives of these peptides. Towards this end methods that employ selective proteolytic cleavage of these fragments from fibrinogen have been developed. Both the N-DSK fragment, produced by CNBr cleavage of fibrinogen, and Bβ 1-118 were employed as substrates for plasmin with the finding of higher yields from N-DSK. Bβ 1-42 and Bβ 1-21 were purified by gel filtration and ion-exchange chromatography on SP-Sephadex using volatile buffers. When the purified preparation of Bβ 1-42 was chromatographed on reverse-phase high performance liquid chromatography, two peaks of identical amino acid composition were separated, presumably due either to pyroglutamate or to amide differences.

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