Mechanical Deformation in Conductive Adhesives as Measured With Electron-Beam Moire´

1999 ◽  
Vol 121 (2) ◽  
pp. 69-74 ◽  
Author(s):  
E. S. Drexler ◽  
J. R. Berger
Keyword(s):  
Electron Beam ◽  
Mechanical Deformation ◽  
Shear Mode ◽  
Conductive Adhesives ◽  
Additional Loading ◽  
The Matrix ◽  
Film Specimen ◽  
Shear Strains ◽  
Electron Beam Moiré

Two forms (paste and film) of isotropically conductive adhesives (CAs) were mechanically loaded in shear mode. The specimens were instrumented with crossed-line gratings so that normal and shear displacements could be measured. The CA paste specimen failed outside the observed region at a stress 28 percent below the manufacturer’s predicted value. In the observed region there were no normal strains, only shear strains restricted to the CA. In the film specimen the conducting particles began breaking away from the matrix epoxy at very low loads. However, the specimen continued carrying the additional loading increments until the load was transferred to the adjacent material.

Electron-Beam Moiré Study Of Local Deformation In Conductive Adhesives

1996 ◽  
Vol 445 ◽  
Author(s):  
E. S. Drexler ◽  
J. R. Berger
Keyword(s):  
Electron Beam ◽  
Cross Section ◽  
Strain Measurement ◽  
Local Deformation ◽  
Large Displacements ◽  
Conductive Adhesives ◽  
Lap Shear ◽  
Film Specimen ◽  
Measurement Capabilities ◽  
Scanning Electron

AbstractElectron-beam (e-beam) moiré is a recently developed technique for micro-mechanics. It allows one to combine the resolution of the scanning electron microscope (SEM) with the strain measurement capabilities of moiré. With e-beam moiré we are able to study locally the effect of temperatures ranging between −50 and 150 °C on conductive adhesives (CAs) and their interfaces. With this technique we measured the local displacements due to the thermal expansion of the copper and the CA. The modified lap-shear specimens were made of copper-to-copper attached with CAs and cured according to the manufacturer's instructions. A cross section of each material was polished and a moiré grating was written on the surface using e-beam lithography techniques. Digital images of the moiré were collected from the SEM at regular temperature intervals. The images were compared and the displacements measured. Local regions of large displacements were observed in the paste specimen. Permanent deformations in the film specimen resulted from exceeding the glass transition temperature of the CA.

Measurement of electron beam moire fringes with pulsed-dilation framing camera using different lasers

Optik ◽  
2019 ◽  
Vol 195 ◽  
pp. 163149
Author(s):  
Yanli Bai ◽  
Rongbin Yao ◽  
Haiying Gao ◽  
Xun Wang ◽  
Dajian Liu
Keyword(s):  
Electron Beam ◽  
Moiré Fringes ◽  
Framing Camera ◽  
Electron Beam Moiré

Analysis of an extraordinary electron beam moiré phenomena in a pulse-dilation framing camera

Optik ◽  
2019 ◽  
Vol 199 ◽  
pp. 163516
Author(s):  
Yanli Bai ◽  
Rongbin Yao ◽  
Haiying Gao ◽  
Xun Wang ◽  
Dajian Liu
Keyword(s):  
Electron Beam ◽  
Framing Camera ◽  
Electron Beam Moiré

Intermetallic Matrix Composites by Physical Vapor Deposition

1990 ◽  
Vol 194 ◽  
Author(s):  
Dallis A. Hardwick ◽  
Richard C. Cordi
Keyword(s):  
Electron Beam ◽  
Cross Sections ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Sheet Material ◽  
Electron Beam Evaporation ◽  
Layered Composite ◽  
Auger Analysis ◽  
The Matrix ◽  
Intermetallic Matrix Composites

AbstractThe feasibility of producing layered composite sheet material, in which the matrix is the intermetallic compound TiAl, using physical vapor deposition (PVD) has been demonstrated. The PVD techniques of sputtering and electron beam evaporation were both investigated. Films were deposited by alternately sputtering from targets of composition Ti-53A1–3Nb and TiB2 or were co-deposited from separate electron beam heated hearths containing Ti and Al. In the latter case, nitrogen gas was pulsed into the deposition chamber at controlled intervals resulting in the formation of a TiAl/TiAlN layered composite. The composition of the films was determined using Auger analysis and Rutherford backscattering spectroscopy and the crystal structure was checked using X-ray and electron diffraction. Cross-sections through the films were prepared for examination by transmission electron microscopy so that the layered microstructure of the films could be verified.

scholarly journals Continuous Bamboo Fibers/Fire-Retardant Polyamide 11: Dynamic Mechanical Behavior of the Biobased Composite

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 299
Author(s):  
Louise Lods ◽  
Tutea Richmond ◽  
Jany Dandurand ◽  
Eric Dantras ◽  
Colette Lacabanne ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Security Requirements ◽  
Shear Mode ◽  
Calorimetric Study ◽  
Experimental Conditions ◽  
Polyamide 11 ◽  
Melamine Cyanurate ◽  
Dynamic Mechanical ◽  
The Matrix ◽  
Bamboo Fibers

A biobased composite was generated from bamboo fibers (BF) and a polyamide 11 (PA11) matrix. In order to fulfill security requirements, a PA11 already containing a flame retardant (FR) was chosen: This matrix is referred as PA11-FR. In this work, the effects of flame retardant (melamine cyanurate) on the composite properties were considered. In the calorimetric study, the glass transition and melting temperatures of PA11-FR were the same as those of PA11. The melamine cyanurate (MC) had no influence on these parameters. Thermogravimetric analysis revealed that PA11-FR was less stable than PA11. The presence of MC facilitated thermal decomposition regardless of the analysis atmosphere used. It is important to note that the presence of FR did not influence processing conditions (especially the viscosity parameter) for the biosourced composite. Continuous BF-reinforced PA 11-FR composites, single ply, with 60% of fibers were processed and analyzed using dynamic mechanical analysis. In shear mode, comparative data recorded for BF/PA11-FR composite and the PA11-FR matrix demonstrated that the shear glassy modulus was significantly improved: multiplied by a factor of 1.6 due to the presence of fibers. This result reflected hydrogen bonding between reinforcing fibers and the matrix, resulting in a significant transfer of stress. In tensile mode, the conservative modulus of BF/PA11-FR reached E’ = 8.91 GPa. Upon BF introduction, the matrix tensile modulus was multiplied by 5.7. It can be compared with values of a single bamboo fiber recorded under the same experimental conditions: 31.58 GPa. The difference is partly explained by the elementary fibers’ lack of alignment in the composite.

scholarly journals Numerical Simulation and Microstructure and Properties of 45 Steel by Scanning Electron Beam Bevel Polishing

2021 ◽  
Vol 2133 (1) ◽  
pp. 012032
Author(s):  
Tenghui Xia ◽  
Chunping Du ◽  
Zhiyong Liu ◽  
Jian Lu ◽  
Zhifa Zhu
Keyword(s):  
Surface Layer ◽  
Electron Beam ◽  
Lath Martensite ◽  
Mixed Phase ◽  
Scanning Electron Beam ◽  
Good Surface ◽  
The Matrix ◽  
Continuous Scanning ◽  
Inclination Angles ◽  
Scanning Electron

Abstract In order to obtain metal products with good surface quality, it is necessary to develop an efficient bevel polishing method. Therefore, this article Uses continuous scanning electron beam polishing. The surface of the material undergoes rapid melting and solidification and generates a dynamic temperature field. The polishing treatment improves the microstructure of the surface layer of the quenched and tempered 45 steel, and significantly increases the microhardness of the surface layer. The hardness after treatment can reach up to 747.6Hv, which is about 2.4 times higher than the matrix; the structure after hardening is transformed from the mixed phase of coarse acicular martensite and lath martensite to hidden acicular martensite and retained austenite a mixed phase thereof. In addition, after bevels with different inclination angles are subjected to electron beam surface polishing modification treatments with different scanning speeds, under the same parameters, as the inclination angle increases, the hardness value at the same position decreases.

Mechanism of Silicon Plate Decay in Aluminum Matrix under Electron Beam Effect

2020 ◽  
Vol 839 ◽  
pp. 32-36
Author(s):  
Vladimir Sarychev ◽  
Sergey Nevskii ◽  
Sergey Konovalov ◽  
Alexander Semin ◽  
Elena Martusevich ◽  
...  
Keyword(s):  
Electron Beam ◽  
Wave Length ◽  
Aluminum Matrix ◽  
Mechanical Stresses ◽  
High Current Electron Beam ◽  
Initial Stage ◽  
The Matrix ◽  
Current Electron ◽  
Rayleigh Taylor Instability ◽  
Expansion Coefficients

The decay mechanism of silicon particles in silumin in the thermal effect zone of low-energy high-current electron beam is proposed. Its essence consists in the fact that under the effect of the mechanical stresses the interface of silicon inclusion with aluminum matrix becomes instable resulting in the decay of silicon particle. It was supposed that the instability was the analog of Rayleigh-Taylor instability. The mechanical stresses arising due to the discrepancy of the elastic moduli and the linear expansion coefficients of the inclusion and the matrix are the analogs of gravity force. The analysis of the initial stage of instability within the frameworks of the visco-potential approximation has shown that the dependence of the rate of perturbations’ growth has only one maximum which falls on the wave length of the order ≈ 500 nm that is 5-fold higher than that of the experimental data. Such a discrepancy may be explained by the fact that when developing the model the temperature of the silicon inclusion and the aluminum matrix was considered to be constant, similar and being equal to the eutectic temperature of silumin. In fact, the temperatures of the inclusion and the matrix are different. To take into account the influence of these facts on the instability of the interface the new investigations are necessary.

Electron beam moiré

1993 ◽  
Vol 33 (4) ◽  
pp. 270-277 ◽  
Author(s):  
J. W. Dally ◽  
D. T. Read
Keyword(s):  
Electron Beam ◽  
Electron Beam Moiré

Lattice defects in lawsonite: a TEM investigation

2001 ◽  
Vol 65 (1) ◽  
pp. 33-39 ◽  
Author(s):  
F. Cámara ◽  
J. C. Doukhan ◽  
M. A. Carpenter
Keyword(s):  
Electron Beam ◽  
Low Temperature ◽  
High Mobility ◽  
High Sensitivity ◽  
Lattice Defects ◽  
Coffee Bean ◽  
Transmission Electron ◽  
The Matrix ◽  
Antiphase Domains

AbstractLattice defects in lawsonite have been studied by transmission electron microscopy. It is proposed that twinning and easy glide systems are 1/2[110] {110}; the easy glide planes are coincident with twin planes. This mineral displays high sensitivity to the electron beam, even at low temperatures. In situ precipitates appear as a consequence of beam irradiation. The precipitation takes places first on dislocations, then on twin boundaries and then in the matrix, causing ‘coffee-bean’ contrast features typical of precipitates. The studies were performed at low temperature (∼110 K) in order to investigate the low temperature displacive transitions from space group Cmcm to Pmcn and P21cn and elucidate their microscopic character. No characteristic microstructural texture, such as antiphase domains associated with the transition, were observed, however. This is probably due to the high mobility of protons under the electron beam. The development of regularly spaced dislocations along twin planes is hypothesized as the only evidence that a phase transition takes place at a nanoscale.

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