scholarly journals The Microhardness as an Express Method for Estimation the Depth of Metal Particle Distribution

2016 ◽  
Vol 6 (1) ◽  
pp. 37
Author(s):  
L.L. Muhina ◽  
I.V. Razumovskaja ◽  
S.K. Kudaikulova ◽  
B.A. Zhubanov ◽  
M.J.M. Abadie
Keyword(s):  
Metal Particle ◽  
Particle Distribution ◽  
Polymeric Materials ◽  
Microhardness Measurement ◽  
Metal Particles ◽  
Silver Layer ◽  
Express Method ◽  
Polyimide Films

By measurement of microhardness of silver layer on polyimide films and its reduction after removing the stress, the depth of silver distribution in the polyimide films was calculated. A significant hardening of Kapton 100 HN films was observed especially for cobalt-impregnated materials, which was about 10 μm. The distribution of silver in the film layers was obviously deeper that manifested as entirely lower hardening at microhardness measurement. Because of the initial microhardness of Upilex it was observed strong hardening of the effort, which was led to shallow distribution of metals in the films. For example, Cometallized films showed 5 μm distribution in the top film layers. Such method could allow precisely and rapidly estimating the distribution of metal particles impregnated in metallized polymeric materials.

Electron Microscopy of the Shape of Small Metal Particles

1977 ◽  
Vol 35 ◽  
pp. 300-301
Author(s):  
M. Jose Yacaman
Keyword(s):  
Electron Microscopy ◽  
Metal Particle ◽  
Field Experiments ◽  
Size Range ◽  
Dark Field ◽  
Metal Particles ◽  
Bragg Condition ◽  
Crystal Particle ◽  
Small Metal Particle ◽  
Small Metal Particles

In the Study of small metal particles the shape is a very Important parameter. Using electron microscopy Ino and Owaga(l) have studied the shape of twinned particles of gold. In that work electron diffraction and contrast (dark field) experiments were used to produce models of a crystal particle. In this work we report a method which can give direct information about the shape of an small metal particle in the amstrong- size range with high resolution. The diffraction pattern of a sample containing small metal particles contains in general several systematic and non- systematic reflections and a two-beam condition can not be used in practice. However a N-beam condition produces a reduced extinction distance. On the other hand if a beam is out of the bragg condition the effective extinction distance is even more reduced.

scholarly journals Microfluidic Airborne Metal Particle Sensor Using Oil Microcirculation for Real-Time and Continuous Monitoring of Metal Particle Emission

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 825
Author(s):  
Jong-Seo Yoon ◽  
Jiwon Park ◽  
Hye-Rin Ahn ◽  
Seong-Jae Yoo ◽  
Yong-Jun Kim
Keyword(s):  
Real Time ◽  
Metal Particle ◽  
Continuous Monitoring ◽  
Metal Particles ◽  
Minimum Size ◽  
Capacitive Sensing ◽  
Test Bed ◽  
Optimal Frequency ◽  
Site Monitoring ◽  
Cost Efficient

Airborne metal particles (MPs; particle size > 10 μm) in workplaces result in a loss in production yield if not detected in time. The demand for compact and cost-efficient MP sensors to monitor airborne MP generation is increasing. However, contemporary instruments and laboratory-grade sensors exhibit certain limitations in real-time and on-site monitoring of airborne MPs. This paper presents a microfluidic MP detection chip to address these limitations. By combining the proposed system with microcirculation-based particle-to-liquid collection and a capacitive sensing method, the continuous detection of airborne MPs can be achieved. A few microfabrication processes were realized, resulting in a compact system, which can be easily replaced after contamination with a low-priced microfluidic chip. In our experiments, the frequency-dependent capacitive changes were characterized using MP (aluminum) samples (sizes ranging from 10 μm to 40 μm). Performance evaluation of the proposed system under test-bed conditions indicated that it is capable of real-time and continuous monitoring of airborne MPs (minimum size 10 μm) under an optimal frequency, with superior sensitivity and responsivity. Therefore, the proposed system can be used as an on-site MP sensor for unexpected airborne MP generation in precise manufacturing facilities where metal sources are used.

Time-Dependent Fracture of Polyimide Films

1993 ◽  
Vol 115 (3) ◽  
pp. 264-269 ◽  
Author(s):  
S. F. Popelar ◽  
C. H. Popelar ◽  
V. H. Kenner
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Crack Growth ◽  
Practical Implication ◽  
Slow Crack Growth ◽  
Polymeric Materials ◽  
Polyimide Films ◽  
Test Protocol ◽  
Fracture Tests

A fracture mechanics approach for quantifying slow crack growth in thin polyimide films and assessing their structural integrity and life expectancy is presented. The methodology and techniques developed in this investigation may also be applied to other polymeric materials. A test protocol for studying slow crack growth is described. Room temperature fracture tests were performed and an analysis model was developed and validated to analyze the fracture tests. Correlations between the rate of crack growth and the crack driving force as measured by the stress intensity factor were made and contrasted for Kapton 100HN, 300H and 500HN polyimide films. The crack growth rate was found to depend very strongly upon the stress intensity factor. The practical implication of this finding is that the fracture of these polyimide films may be approximated as being controlled by a critical value of the stress intensity factor.

Impact of metal particle size on partial discharge characteristics of moving metal particles in transformer oil

2019 ◽  
Vol 731 ◽  
pp. 136577 ◽  
Author(s):  
Shouxiao Ma ◽  
Dongmei Yang ◽  
Bin Liang ◽  
Ying Jin
Keyword(s):  
Particle Size ◽  
Metal Particle ◽  
Partial Discharge ◽  
Transformer Oil ◽  
Metal Particles ◽  
Discharge Characteristics ◽  
Metal Particle Size

Theory of metal particle ignition I. Ignition of metal particles in the formation of solid solutions

1979 ◽  
Vol 15 (3) ◽  
pp. 299-304 ◽  
Author(s):  
A. B. Arutyunyan ◽  
S. L. Kharatyan ◽  
A. G. Merzhanov
Keyword(s):  
Solid Solutions ◽  
Metal Particle ◽  
Metal Particles ◽  
Particle Ignition

scholarly journals Polymer substrates for flexible photovoltaic cells application in personal electronic system

2016 ◽  
Vol 24 (1) ◽  
Author(s):  
K. Znajdek ◽  
M. Sibiński ◽  
A. Strąkowska ◽  
Z. Lisik
Keyword(s):  
Photovoltaic Cells ◽  
Polymeric Materials ◽  
Electronic System ◽  
Electronic Systems ◽  
Flexible Substrates ◽  
Polyimide Films ◽  
Polymer Substrates ◽  
The Third ◽  
Visible Light Range ◽  
High Elasticity

The article presents an overview of polymeric materials for flexible substrates in photovoltaic (PV) structures that could be used as power supply in the personal electronic systems. Four types of polymers have been elected for testing. The first two are the most specialized and heat resistant polyimide films. The third material is transparent polyethylene terephthalate film from the group of polyesters which was proposed as a cheap and commercially available substrate for the technology of photovoltaic cells in a superstrate configuration. The last selected polymeric material is a polysiloxane, which meets the criteria of high elasticity, is temperature resistant and it is also characterized by relatively high transparency in the visible light range. For the most promising of these materials additional studies were performed in order to select those of them which represent the best optical, mechanical and temperature parameters according to their usage for flexible substrates in solar cells.

Two types of metal particle in the Bachmut (L6) chondritic meteorite

1986 ◽  
Vol 50 (356) ◽  
pp. 317-322
Author(s):  
V. P. Semenenko ◽  
L. G. Samoilovich ◽  
B. V. Tertichnaya
Keyword(s):  
Chemical Composition ◽  
Thermal History ◽  
Metal Particle ◽  
Metal Particles ◽  
Cu Content

AbstractMetal particles in the Bachmut chondrite may be subdivided into large (hundreds of μm in size) and small (1–10 µm in size) varieties. They differ in the ratio of their constituent phases, in structure, and in chemical composition. Large particles are richer in Ni than small ones, the latter being characterized by an abnormally high Cu content. It is suggested that different pre-accretion histories were responsible for producing the various types of metal grains, and that, during post-accretion thermal history, temperatures were too low to cause elemental redistribution among the grains.

Morphology and Dielectric Property of Cellular Polyimide Films Prepared by Phase Inversion

2012 ◽  
Vol 557-559 ◽  
pp. 704-707
Author(s):  
Hui Juan Chu ◽  
Hong Liang Wei ◽  
Jing Zhu ◽  
Bao Ku Zhu ◽  
You Yi Xu
Keyword(s):  
Dielectric Properties ◽  
Dielectric Property ◽  
Phase Inversion ◽  
Polymeric Materials ◽  
Dielectric Constants ◽  
Cellular Structures ◽  
Coagulation Bath ◽  
Inversion Method ◽  
Polyimide Films ◽  
Chemical Structures

In order to explore low dielectric polymeric materials, two types of cellular polyimide films with different dianhydride units were prepared by phase inversion method, and their dielectric properties were investigated. Polyimide films with various cellular structures were obtained by controlling coagulation bath compositions and temperatures. The effects of chemical structures, cellular structures on dielectric property of cellular polyimide films were studied. The results showed that all of the cellular polyimide films had lower dielectric constants than the polymer matrix. The dielectric properties were influenced dominantly by the morphologies of the films. Cellular Polyimide films filled with uniform small cellular structures behaved excellent dielectric property compared with those large-pore cellular films. These findings would provide potential application for cellular polyimide films in microelectronic devices.

scholarly journals Optimum Disposition of Metal Particles in the Propellant Grain

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Leonid L. Minkov ◽  
Ernst R. Shrager ◽  
Elizaveta V. Pikushchak
Keyword(s):  
Metal Particle ◽  
Specific Impulse ◽  
Combustion Products ◽  
Combustion Efficiency ◽  
Metal Particles ◽  
Phase Flow ◽  
Solid Propellants ◽  
Two Phase ◽  
Cross Sectional ◽  
Metal Combustion

Using the dispersed metal in solid propellants to increase the temperature of combustion products leads to such a problem as the specific impulse loss due to the incomplete combustion of metal particles in the exhaust products. A redistribution of metal loaded into the propellant grain is one of the methods to decrease the specific impulse loss. This paper reports on the ways to obtain the optimum metal particle disposition for the case-bounded propellant grain of tube cross-sectional type. Three different approaches to analyze the metal combustion efficiency are discussed. The influence of the dynamic nonequilibrium of two-phase flow on the optimum metal particles disposition in the propellant grain of tube cross-sectional type is investigated.

scholarly journals Explanation of the express method of the determination of steel grade by spark

2015 ◽  
Vol 1 ◽  
pp. 157
Author(s):  
Igor Nikiforov ◽  
Pavel Maltsev ◽  
Vladimir Ivanov ◽  
Inna Barsuk
Keyword(s):  
Steel Grade ◽  
Metal Particles ◽  
Express Method ◽  
Chemical Theory ◽  
Physico Chemical

<p>On the basis of physico-chemical theory of burning metal particles, the explanation known method of determining the grade of steel for the spark when it is grinding is performed. The features of formation of globules are reviewed and given them a brief description. The conditions for the formation of a spark in the processing of steels and alloys of various grades are researched.</p>

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