Rapid Growth of Tin Whiskers on the Surface of Sn3.8Ag0.7Cu1.0Y Alloy

2012 ◽  
Vol 557-559 ◽  
pp. 1397-1403
Author(s):  
Jun Tian ◽  
Hu Hao
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Rapid Growth ◽  
Trace Amount ◽  
Volume Expansion ◽  
Solder Matrix ◽  
Chemical Activity ◽  
Tin Whiskers ◽  
High Chemical ◽  
High Chemical Activity

It is known that rare-earth elements exhibit high chemical activity and adding trace amount of rare-earth Y in the solder can significantly improve the properties of solder alloy. However, adding excessive rare-earth Y in the solder will result in rapid growth of tin whiskers. The research results show that: if the YSn3 precipitates formed in the interior of Sn3.8Ag0.7Cu1.0Y were exposed to the air, YSn3 precipitates will oxidize and expand in volume, and the tremendous compressive stress produced by the surrounding solder matrix constraining the volume expansion will accelerate the growth of tin whiskers.

scholarly journals Effects of Adding Active Elements to Aluminum-Based Filler Alloys on the Bonding of 6061 Aluminum Alloy and Alumina

2021 ◽  
Vol 11 (21) ◽  
pp. 10440
Author(s):  
Yu-Kai Sun ◽  
Shih-Ying Chang ◽  
Lung-Chuan Tsao ◽  
Tung-Han Chuang ◽  
Guo-Zhan Zhang ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Active Element ◽  
Chemical Activity ◽  
Filler Alloy ◽  
High Chemical ◽  
6061 Aluminum Alloy ◽  
Element Addition ◽  
Average Bond ◽  
High Chemical Activity

In this study, AA6061/AA6061 and AA6061/alumina were directly brazed with Al10.8Si10Cu, Al10Si10Cu4Ti and Al10Si10Cu4Ti0.1RE filler alloys at 530 °C for 10 min without the use of flux. The addition of titanium and rare-earth elements into Al10.8Si10Cu alloy effectively improved the bonding shear strengths of AA6061/AA6061 and AA6061/alumina joints. The highest joint shear strengths were 61.1 and 19.2 MPa, respectively. The Al10.8Si10Cu filler alloy without titanium and rare-earth elements could not wet on the alumina and caused failure of the AA6061/alumina joint. The shear strengths of the AA6061/AA6061 and AA6061/alumina joints both strongly depended on the active element addition. Due to the high chemical activity of the rare-earth elements, they formed AlLa between the Al10Si10Cu4Ti0.1RE filler alloy and alumina. The addition of rare-earth elements into Al10Si10Cu4Ti filler alloy resulted in significant enhancement of the average bond strength of AA6061/alumina joints, from 8.0 to 14.8 MPa.

Substrate Influence in YBaCuO Melt-Texturing Growth

1992 ◽  
Vol 275 ◽  
Author(s):  
N. Pellerin ◽  
M. Gervais ◽  
P. Odier
Keyword(s):  
Chemical Activity ◽  
High Chemical ◽  
Melt Texturing ◽  
Substrate Influence ◽  
High Chemical Activity

Melt-texturing of YBaCuO is generally processed on substrates. Due to its high chemical activity, the non-stoichiometric liquid, mainly due to the barium element, generally reacts with the substrate which is therefore subjected to play a role in the crystallization of YBaCuO and in the development of the texture. The particular case of Y2O3, which is a reacting but non-polluting substrate, is treated in details. The comparison of textured YBaCuO in similar conditions but on different substrates: Al2O3, Y2O3 and MgO gives some insight in the texturing process.

scholarly journals The use of 19F in Medicine in Poland and in the World

2021 ◽  
Vol 12 (6) ◽  
pp. 8561-8572
Keyword(s):  
Chemical Element ◽  
Chemical Activity ◽  
Toxic Effects ◽  
Large Impact ◽  
High Chemical ◽  
High Affinity ◽  
The World ◽  
Living Organisms ◽  
Very High ◽  
High Chemical Activity

Fluorine is a chemical element belonging to the group of halogens. Due to its many properties, it has been used in various fields of medicine, mainly in dentistry, pharmacology, oncology, and radiology. It is an element that occurs naturally in the environment with a very high chemical activity. In addition, it has a high affinity for calcium or magnesium [1], which may have a large impact on the body's functioning when a higher dose of fluoride is taken. Moreover, fluorine is an element that has toxic effects, not only on living organisms but also on the environment. Fluoride-based preparations are widely used in several areas of medicine. This paper presents the use of fluoride in its various branches of medicine.

scholarly journals Carbon as an Effective Modifier of Silicon Dioxide and Reagent for Obtaining Nanostructurized SHS-Composites

2011 ◽  
Vol 14 (1) ◽  
pp. 31
Author(s):  
Z.A. Mansurov ◽  
N.N. Mofa
Keyword(s):  
Silicon Dioxide ◽  
Chemical Activity ◽  
Powder Materials ◽  
Redox Processes ◽  
Nanosized Particles ◽  
High Chemical ◽  
Structure And Morphology ◽  
Composition Materials ◽  
Composition Structure ◽  
High Chemical Activity

The peculiarities of the structure and morphology of quartz particles modified by carbon depending on MCT conditions and type of specific carbonaceous modifier were studied. Powder materials with the composition structure of the materials, which are hybrid formations organics-inorganics with a high chemical activity of its components, were obtained by combined MCT of carbon or carbon containing organic compounds with quartz. A high chemical activity of quartz particles modified by carbon is effectively realized when producing SHS-ceramics composition materials. The rate of redox processes increases, the initial reagents are most completely realized and nanosized particles of silicon carbide are formed. It is shown how one can regulate the process of combustion in SH-synthesis and produce the material of the necessary quality by modifying silicon dioxide particles in the course of MCT.

A second species of the genus Thermochiton Saito et Okutani, 1990 (Mollusca: Polyplacophora)

2020 ◽  
Vol 30 (1) ◽  
pp. 7-12
Author(s):  
B. I. Sirenko
Keyword(s):  
New Species ◽  
Papua New Guinea ◽  
New Guinea ◽  
Chemical Activity ◽  
High Chemical ◽  
Deep Waters ◽  
A New Species ◽  
High Chemical Activity

The paper describes a new species of the genus , sp. nov., found in deep waters off Papua New Guinea. This species differs from primarily in the dorsal scales, the marginal spicules, sculpture of the jugal area and the shape of the central teeth of radula. There are apparent similarities between the species of the genus Thermochiton , Connexochiton platynomenus , C. kaasi and Ischnochiton crassus. The last species is proposed to be transferred to . Owing to the friable, rusty brown deposits that densely cover the shell and girdle of both specimens of , the latter probably lives in areas of high chemical activity.

Potentiometric NO2 Sensor Based on YSZ and WS2

2016 ◽  
Vol 680 ◽  
pp. 212-215
Author(s):  
Jian Wu ◽  
Cheng Zhang ◽  
Jin Feng Xia ◽  
Dan Yu Jiang
Keyword(s):  
Linear Correlation ◽  
Electrochemical Sensors ◽  
Chemical Activity ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
High Chemical ◽  
Efficient Catalyst ◽  
Temperature Oxidation ◽  
Structure Surface ◽  
High Chemical Activity

In this study, Yttria-stabilized zirconia (YSZ) electrochemical sensors attached with the WS2 sensing electrode (SE) were fabricated and examined for NO2 sensing properties. Due to its internal stratiform structure, surface and edge of the lamella have high chemical activity, WS2 was used as a kind of highly efficient catalyst. WS2 was partial oxidated to WO3 at 400°C, and with the increment of temperature, oxidation will accelerate. The ΔEMF to 500 ppm NO2 was as high as 125mv at 400°C, while the value of WO3-based sensor was as small as 10 mv in the same condition. These WS2-attached devices gave a linear correlation between EMF and the logarithm of NO2 concentration from 30 to 500 ppm in the temperature range 350–500°C. The response time of the device is about 1 min at 400°C.

scholarly journals High Chemical Activity of a Perovskite Surface: Reaction of CO withSr3Ru2O7

2014 ◽  
Vol 113 (11) ◽  
Author(s):  
Bernhard Stöger ◽  
Marcel Hieckel ◽  
Florian Mittendorfer ◽  
Zhiming Wang ◽  
David Fobes ◽  
...  
Keyword(s):  
Surface Reaction ◽  
Chemical Activity ◽  
High Chemical ◽  
High Chemical Activity

scholarly journals Chemical and Biochemical Onslaught of Anthropogenic Airborne Species on the Heritage Monument of the Taj Mahal

Heritage ◽  
2019 ◽  
Vol 2 (3) ◽  
pp. 2137-2159 ◽  
Author(s):  
Deepankar Banerjee ◽  
Sabyasachi Sarkar
Keyword(s):  
Chemical Constituents ◽  
Chemical Activity ◽  
Oxygen Species ◽  
Plant Origin ◽  
High Chemical ◽  
Physico Chemical ◽  
Micro Level ◽  
Taj Mahal ◽  
Over The Top ◽  
High Chemical Activity

The science on the anthropogenic airborne aerosols impacting the World Heritage marble monument, the Taj Mahal, at Agra, has been studied in the light of modern physico-chemical approaches. The study is an effort to understand unrecognized airborne species which were found on the surface of the Taj Mahal monument. These species have been analyzed in the light of current analytical methods to impart characterization features and their possible impacts on the surface of the marble. Chemical constituents of these substrates, which were incorporated over the top surface of the monument, have been identified. Interestingly, the carbon particulates which were found on the micro level, popularly called “particulate matters”, have now been identified in the nano domain entity, which is chemically more reactive, and have been found on the surface of the monument. Because of their high chemical activity, these nano carbons have a newer chemistry in the presence of air and sunlight, generating several reactive oxygen species (ROS). These ROS are capable of responding to complicated chemical reactions on the surface of the marble in association with deposited cyanophyceae and other deposits of plant origin, causing rapid degradation. This study provides the nature of the onslaught of such monuments exposed under the prevalent smoggy environmental scenario.

scholarly journals Reversible ionically-crosslinked single chain nanoparticles as bioinspired and recyclable nanoreactors forN-heterocyclic carbene organocatalysis

2018 ◽  
Vol 9 (43) ◽  
pp. 5286-5294 ◽  
Author(s):  
Sofiem Garmendia ◽  
Andrew P. Dove ◽  
Daniel Taton ◽  
Rachel K. O'Reilly
Keyword(s):  
Ionic Liquid ◽  
Chemical Activity ◽  
Flexible Structure ◽  
Single Chain ◽  
High Chemical ◽  
Poly Ionic Liquid ◽  
High Chemical Activity

The intrinsic advantages of poly(ionic liquid)s (PILs), based on their high chemical activity and flexible structure, have been harnessed by exploring their applicability as catalytic single chain nanoparticles (SCNPs).

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