In-situ Tensile Straining of Metal Films on Polymer Substrates under an AFM

2013 ◽  
Vol 1527 ◽  
Author(s):  
M.J. Cordill ◽  
V.M. Marx
Keyword(s):  
Optical Microscope ◽  
Metal Films ◽  
Scanning Electron Micrographs ◽  
Adhesion Properties ◽  
Polymer Substrates ◽  
Fragmentation Test ◽  
First Occurrence ◽  
Film Substrate ◽  
Scanning Electron

ABSTRACTMetal films on polymer substrates are commonly used in flexible electronic devices and as gas barrier coatings. One way to evaluate the fracture and adhesion properties of such film systems is the fragmentation test. In the fragmentation test a film-substrate system is strained in tension under an optical microscope or inside a scanning electron microscope to observe the cracking and delamination events in situ. The technique works very well for brittle metal and ceramic films. However, when ductile films are strained they deform plastically before cracks and buckles appear. Therefore, a tensile straining device was developed to fit under an AFM for in situ observation of ductile metal films on polymer substrates. With the new in situ device the first occurrence of plastic deformation in the form of localized thinning of the film and channel cracks are visible. These features can only be detected through a height difference in the AFM images and not with optical or scanning electron micrographs. A comparison to brittle Cr films on polymer substrates was performed.

Study on Mechanical Properties of AA6351 Alloy Reinforced with Titanium Di-Boride (TiB2) Composite by In Situ Casting Method

2015 ◽  
Vol 787 ◽  
pp. 583-587 ◽  
Author(s):  
V. Mohanavel ◽  
K. Rajan ◽  
K.R. Senthil Kumar
Keyword(s):  
Tensile Strength ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composites ◽  
Scanning Electron Micrographs ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
In Situ Reaction ◽  
Halide Salts ◽  
Scanning Electron

In the present study, an aluminum alloy AA6351 was reinforced with different percentages (1, 3 and 5 wt %) of TiB2 particles and they were successfully fabricated by in situ reaction of halide salts, potassium hexafluoro-titanate and potassium tetrafluoro-borate, with aluminium melt. Tensile strength, yield strength and hardness of the composite were investigated. In situ reaction between the inorganic salts K2TiF6 and KBF4 to molten aluminum leads to the formation of TiB2 particles. The prepared aluminum matrix composites were characterized using X-ray diffraction and scanning electron microscope. Scanning electron micrographs revealed a uniform dispersal of TiB2 particles in the aluminum matrix. The results obtained indicate that the hardness and tensile strength were increased with an increase in weight percentages of TiB2 contents.

Removing the Barriers to Next Generation'S Dielectric Films: In Situ Void-Free Planarized Films

1990 ◽  
Vol 203 ◽  
Author(s):  
J.R. Monkowski ◽  
M.A. Logan ◽  
L.F. Wright
Keyword(s):  
Aspect Ratio ◽  
Ion Chromatography ◽  
Field Measurements ◽  
Dielectric Films ◽  
Breakdown Field ◽  
Scanning Electron Micrographs ◽  
Aspect Ratios ◽  
New Process ◽  
Scanning Electron

ABSTRACTIn the next generation of semiconductor devices, minimum dimensions will be smaller, aspect ratios (height to width) of devices features will be larger, and BPSG dielectrics will be challenged to deal with these changes. A new process, which integrates deposition, flow, and anneal of BPSG films, and allows void-free filling of high-aspect-ratio trenches with excellent surface planarization, is presented in this paper. Scanning electron micrographs are used to show the extent of film coverage and planarization. Additional characterization includes ion chromatography, ellipsometry, stress measurements, and breakdown field measurements.

Investigation on Recovery and Recrystallization of Al-Si-Al2O3 Composites

2013 ◽  
Vol 813 ◽  
pp. 345-350
Author(s):  
Xiong Wei Wang ◽  
Xiao Song Jiang ◽  
De Gui Zhu ◽  
Luo Zhang
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Optical Microscope ◽  
In Situ Synthesis ◽  
Recrystallization Temperature ◽  
Recrystallization Behavior ◽  
Micro Hardness ◽  
Hardness Tester ◽  
Scanning Electron

Al-Si-Al2O3 composites were prepared by powder metallurgy with in-situ synthesis technology. The recovery and recrystallization behavior of Al-Si-Al2O3 composites which underwent compression and then heat-treatment under different temperature were studied using micro-hardness tester, optical microscope (OM) and scanning electron microscopy (SEM) . The results showed that the hardness of composites increased dramatically after compression, and the sample containing 5wt% Si was increasing more evidently than the sample including 10wt%Si. Heat treatment gradually eliminated work hardening; meanwhile the fact that the hardness of composites trended to decline greatly when subjected to annealing suggested occurrence of recovery and recrystallization inside the composites. Recrystallization nucleation preferentially took place in the region near the particle, while the growth of recrystallized grains can also be hindered owning to the pining effect of particles. Depending on the analysis of microstructure and microhardness, it can be concluded that the recrystallization temperature of Al-wt.5%Si-Al2O3 composites was 500°C and the Al-wt.10%Si-Al2O3 composites was 525°C.

scholarly journals Failure by simultaneous grain growth, strain localization, and interface debonding in metal films on polymer substrates

2009 ◽  
Vol 24 (2) ◽  
pp. 379-385 ◽  
Author(s):  
Nanshu Lu ◽  
Xi Wang ◽  
Zhigang Suo ◽  
Joost Vlassak
Keyword(s):  
Grain Growth ◽  
Strain Localization ◽  
Deformation Process ◽  
Copper Film ◽  
Metal Films ◽  
Thin Metal Film ◽  
Interface Debonding ◽  
Growth Strain ◽  
Polymer Substrates ◽  
Film Substrate

In a previous paper, we have demonstrated that a microcrystalline copper film well bonded to a polymer substrate can be stretched beyond 50% without cracking. The film eventually fails through the coevolution of necking and debonding from the substrate. Here we report much lower strains to failure (approximately 10%) for polymer-supported nanocrystalline metal films, the microstructure of which is revealed to be unstable under mechanical loading. We find that strain localization and deformation-associated grain growth facilitate each other, resulting in an unstable deformation process. Film/substrate delamination can be found wherever strain localization occurs. Therefore, we propose that three concomitant mechanisms are responsible for the failure of a plastically deformable but microstructurally unstable thin metal film: strain localization at large grains, deformation-induced grain growth, and film debonding from the substrate.

Mechanical Behavior of Indium Oxide Thin Films on Polymer Substrates

1999 ◽  
Vol 594 ◽  
Author(s):  
D. R. Cairns ◽  
S. M. Sachsman ◽  
D. K. Sparacin ◽  
R. P. Witte ◽  
G. P. Crawford ◽  
...  
Keyword(s):  
Thin Films ◽  
Indium Oxide ◽  
Optical Microscope ◽  
Conducting Layer ◽  
Oxide Thin Films ◽  
Orthogonal Direction ◽  
Polymer Substrates ◽  
Threshold Strain ◽  
Lateral Contraction

AbstractWe report on the change in electrical resistance of tin doped indium oxide thin films on polymer substrates with increasing uniaxial strain. The resistance increases rapidly but continuously above a threshold strain. The threshold strain at which the resistance increases is correlated to the onset of cracking in the oxide film. The strain for cracking and increase in resistance depend upon film thickness. We have measured the distance between neighboring ITO cracks as a function of strain in situ using an optical microscope. At high uniaxial strains the ITO layer fails in the orthogonal direction due to lateral contraction of the polymer substrate. The gradual increase in resistance is modeled assuming there is a conducting layer at the polymer/ITO interface.

scholarly journals Testate Amoebae (Amebozoa: Arcellinida) in Tropical Lakes of Central Mexico

2016 ◽  
Vol 64 (1) ◽  
pp. 377 ◽  
Author(s):  
Itzel Sigala ◽  
Socorro Lozano-García ◽  
Jaime Escobar ◽  
Liseth Pérez ◽  
Elvia Gallegos-Neyra
Keyword(s):  
Volcanic Belt ◽  
Distribution Patterns ◽  
Testate Amoebae ◽  
Optical Microscope ◽  
Tropical Lakes ◽  
Scanning Electron Micrographs ◽  
Taxonomic Richness ◽  
Aperture Diameter ◽  
Eukaryotic Organisms ◽  
Scanning Electron

Testate amoebae are common single-celled eukaryotic organisms in aquatic ecosystems. Despite their important role in these ecosystems, and their potential as bioindicators and paleoindicators, they remain poorly studied in Mexico. The major objectives of this study were to: 1) increase knowledge of testate amoebae in Mexico’s tropical lakes, and 2) create a catalog of high-quality scanning electron micrographs that can be used for future ecological and paleoenvironmental studies. We collected surface-sediment samples from 29 lakes, located in the Transmexican Volcanic Belt, one at each lake during June and October 2011, and March 2013. Sediments were collected with an Ekman grab and preserved in anhydrous ethanol. Sub-samples were observed under a stereomicroscope and morphometric data for each species were recorded. Total diameter and aperture diameter were measured on circular tests. Irregularly shaped tests were measured for length and width of the aperture and for the size of the whole test. If a specimen possessed spines, the length of one randomly selected spine was measured. The best-preserved specimen of each taxon was photographed with an optical microscope and a scanning electron microscope (SEM). We found 41 taxa of testate amoebae belonging to the genera: Arcella, Centropyxis, Cucurbitella, Cyclopyxis, Cyphoderia, Difflugia, Euglypha, Lesquereusia, Pentagonia, Pseudodifflugia and Scutiglypha. Twelve species not previously reported for Mexico were recorded, along with 13 varieties. The average number of taxa recorded in each lake was eight, and the highest taxonomic richness was 18. The taxon found in the greatest number of lakes was Centropyxis aculeata var. aculeata. Taxonomic richness varied among lakes in the same region. This could reflect lake-specific differences in environmental conditions, underscoring the need for more detailed studies that include collection of data on physical and chemical variables in the lakes. Our results highlighted the need of further studies for the distribution patterns and ecology of lacustrine testate amoebae.

scholarly journals Ultrastructural Changes in Chloroplasts in Harvested Broccoli Flower Buds During Senescence

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 824C-824
Author(s):  
Hirofumi Terai ◽  
Hironobu Tsuchida ◽  
Masashi Mizuno ◽  
Yumi Fukui
Keyword(s):  
Structural Changes ◽  
Optical Microscope ◽  
Ultrastructural Changes ◽  
Scanning Electron Micrographs ◽  
Small Particles ◽  
Flower Buds ◽  
Electron Microscopic ◽  
Green Color ◽  
Polyethylene Bags ◽  
Scanning Electron

Green broccoli (Brassica oleracea L. Italica Group) flower heads were stored in perforated polyethylene bags at 20C. Green color of sepals in broccoli flower buds changed to yellow and individual flower buds wilted gradually during storage. Chlorophyllase activity in flower buds tended to increase and chlorophyll content decreased during senescence. Optical and scanning electron microscopic observations were conducted to elucidate the structural changes of chloroplasts in sepals of broccoli flower buds through the senescence. The chloroplasts observed with optical microscope were fine and green when the stage of broccoli flower buds was all green. However, at half-yellow stage, the shapes of chloroplasts obscured and the green color faded. After this stage, colored small particles appeared in the cells and the number of particles tended to increase as yellowing of the flower buds progressed through the senescence. Scanning electron micrographs indicated that the small particles were formed in the chloroplasts and come out from them with senescence followed by aggregation with each other.

Experimental Analysis of the Adhesion of Copper and Chromium Films Deposited on a Polymer

1992 ◽  
Vol 264 ◽  
Author(s):  
M. Ignat ◽  
L. Fayette ◽  
P. Normandon ◽  
F. Templier ◽  
J. Torres
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Interfacial Adhesion ◽  
Polymer Substrate ◽  
Critical Parameters ◽  
Interfacial Damage ◽  
Adhesion Properties ◽  
Film Substrate ◽  
Chromium Films ◽  
Scanning Electron

AbstractAn analysis of bulk and interfacial damage of film/substrate systems consisting of copper or chromium films deposited on a single polymer substrate, is presented here. For these systems (metal/single polymer substrate) the failure analysis is based on the experimental results obtained from deformation experiments performed in a scanning electron microscope. Critical parameters deduced from the experiments, and microstructural observations allow us to discuss the mechanical behaviour of these systems, and their interfacial adhesion properties.

scholarly journals Effect of Implantoplasty on Fatigue Performance and Surface Roughness of Narrow Diameter Dental Implants

2021 ◽  
Author(s):  
Octavi Camps-Font ◽  
Jorge Toledano-Serrabona ◽  
Ana Juiz-Camps ◽  
Rui Figueiredo ◽  
Cosme Gay-Escoda ◽  
...  
Keyword(s):  
Dental Implants ◽  
Visual Inspection ◽  
Bacterial Colonization ◽  
Testing Machine ◽  
Optical Microscope ◽  
Control Group ◽  
Scanning Electron Micrographs ◽  
Number Of Cycles ◽  
Type Of Failure ◽  
Scanning Electron

Abstract Implantoplasty (IP) is used in dental implants with peri-implantitis and aims to remove threads and polish rough surfaces in order to prevent bacterial colonization. As a result of this procedure, implant strength might be compromised. We tested 20 tapered screw-shaped Ti6Al4V dental implants with a simulated bone loss of 50%. Ten implants underwent IP and 10 served as controls. Surface topography (Sa, Sz, Ssk and Sdr) was analyzed with a confocal optical microscope. Subsequently, cyclic loads were applied with a servo-hydraulic mechanical testing machine (5x106 cycles at 15 Hz, between the maximal compression force - 529N in the IP group and 735N in the control group - and 10% of that force). We recorded the number of cycles until failure and the type of failure. Implant failure was analyzed by visual inspection and scanning electron microscopy. Implantoplasty reduced the median Sa from 1.76 (IQR=0.11) to 0.49 (IQR=0.16). The fatigue limits of the control and implantoplasty groups were 551 N and 529 N, respectively. The scanning electron micrographs showed fatigue striations indicating fatigue failure. The infinite life range of the dental implants evaluated was largely above the threshold of usual chewing forces. Implantoplasty seems to render a fairly smooth surface and has a limited impact upon fatigue resistance.

The functional morphology of the retractor lentis muscle of a teleost fish, Astronotus ocellatus

1994 ◽  
Vol 72 (11) ◽  
pp. 1880-1886 ◽  
Author(s):  
M. E. Andison ◽  
J. G. Sivak
Keyword(s):  
Smooth Muscle ◽  
Light Microscopy ◽  
Relative Size ◽  
Lens Capsule ◽  
Scanning Electron Micrographs ◽  
Anatomical Basis ◽  
Astronotus Ocellatus ◽  
Muscle Scanning ◽  
Scanning Electron

Visual teleost species such as the oscar, Astronotus ocellatus, accommodate by moving the lens within the eye. This movement is controlled by a smooth muscle, the retractor lentis. We observed two components in the accommodative lens movement: a nasotemporal and a mediolateral component. In the present study, the anatomical basis of these two components was investigated. Photographs of freshly dissected specimens were used to determine the position and relative size of the retractor lentis muscle in situ. Light microscopy sections reveal two fibre orientations within the muscle. Scanning electron micrographs illustrate that the muscle ligament fans out in two primary directions where it inserts into the lens capsule. The observation that two independent lens movements occur during accommodation is supported anatomically by the orientation of the fibres within the muscle and by the nature of the insertion of the ligament into the lens capsule.

Sign in / Sign up

Export Citation Format

Share Document