The Effect of Current Density on Zinc Whisker Growth

2012 ◽  
Vol 562-564 ◽  
pp. 129-133
Author(s):  
Wen Cui
Keyword(s):  
Current Density ◽  
Whisker Growth ◽  
X Ray Diffraction ◽  
Electronic Components ◽  
X Ray ◽  
Current Densities ◽  
Zinc Coatings ◽  
Surface Morphologies ◽  
Scanning Electron ◽  
Sem Analyses

Zinc whiskers threaten the safety of electronic components due to their electrical conductivity. Factors that control zinc whisker growth are still unknown. The aim of this study was to investigate the effect of current density (1.5, 2.25 and 3.0 A/dm2) on the formation of zinc whiskers, and to relate this to the microstructure of the deposit. Scanning Electron Microscopy (SEM) analyses show that the surface morphologies of deposits became rougher when current density increased; however, nodule density increased from 25/mm2 to 53/mm2 when current density increased from 1.5 to 2.25 A/dm2, and it decreased to 24/mm2 when current density increased to 3.0 A/dm2. X-ray diffraction analyses (XRD) show that the preferred orientation of deposits remain when current densities increased from 1.5 to 2.25 A/dm2, while it changed to when current density increased to 3.0 A/dm2. Results show that zinc coatings electroplated at 2.25 A/dm2 may have greater risk of whisker growth then that electroplated at 1.5 or 3.0 A/dm2.

Sn Whisker Growth in Cu(Top)-Sn(Bottom) Bilayer System upon Room Temperature Aging

2013 ◽  
Vol 785-786 ◽  
pp. 918-923 ◽  
Author(s):  
Lin Huang ◽  
Xue Nian Lin ◽  
Ren Wu Chen ◽  
Jiang Yong Wang
Keyword(s):  
Room Temperature ◽  
Whisker Growth ◽  
X Ray Diffraction ◽  
Sn Whisker ◽  
X Ray ◽  
Bilayer System ◽  
Room Temperature Aging ◽  
Sublayer Thickness ◽  
Temperature Aging ◽  
Scanning Electron

The Sn whisker growth in Cu(top)-Sn(bottom) bilayer system upon room temperature aging was investigated by scanning electron microscope and X-ray diffraction techniques. The experimental observations indicate that the Sn whisker growth on the Cu surface in Cu-Sn bilayer system is different from that on the Sn surface in Sn-Cu bilayer system. When the Sn sublayer thickness is less than 0.5μm, the Sn whisker growth can take place in Cu-Sn system but not in Sn-Cu system. An explanation for Sn whisker growth in Cu-Sn bilayer system is given.

Microwave irradiation used for all steps of pre-pillaring Al-montmorillonite

Clay Minerals ◽  
2009 ◽  
Vol 44 (2) ◽  
pp. 267-278 ◽  
Author(s):  
S. Yapar ◽  
R. M. Torres Sánchez ◽  
M. Emreol ◽  
P. Weidler ◽  
K. Emmerich
Keyword(s):  
Microwave Irradiation ◽  
Physicochemical Properties ◽  
Structural Changes ◽  
Thermal Analyses ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ageing Processes ◽  
Pillared Montmorillonites ◽  
Scanning Electron ◽  
Sem Analyses

AbstractIn this study, a new procedure for the synthesis of pillared clays is proposed. Ageing processes and intercalation reactions were carried out using microwave irradiation in order to decrease the consumption of three industrially-important parameters; time, water consumption and energy. The effects of microwave irradiation, the amount of Al and the Al3+/clay ratio on the physicochemical properties of Al-pillared montmorillonites were investigated. The structural changes, depending on the intercalation and microwave irradiation, were characterized using X-ray diffraction (XRD), Fourier-transform infrared (FTIR) and scanning electron microscopy (SEM) analyses and by measuring the specific surface area and pore-size distribution. Additionally, simultaneous thermal analyses (STA) and zeta potential measurements were carried out to determine physicochemical properties. According to the XRD measurements, the d001 value of microwave-irradiated samples is not affected by the amount of Al and the Al3+/clay ratio; microwave irradiation causes a 0.20 nm contraction in the d001 value in comparison to that of a conventionally pillared sample. The results of FTIR analyses reveal that the intensity of peaks assigned to Keggin-OH and Keggin-H2O stretches is diminished in the case of microwave-irradiated samples. The STA analyses indicate that the amount of water released during dehydroxylation is decreased in the case of microwave-irradiated samples. By considering the contraction in d001 values and the decreases in Keggin-stretching bands and also in the amount of dehydroxylation water, it was concluded that microwave irradiation has a calcination effect.

MAGNETIZATION AND INTRAGRANULAR CRITICAL CURRENT DENSITY IN Yb1Ba2Cu3O7−x HIGH TEMPERATURE SUPERCONDUCTOR

1995 ◽  
Vol 09 (28) ◽  
pp. 3715-3723
Author(s):  
RAANA MAHMOOD ◽  
M. NASIR KHAN ◽  
M. S. ZAFAR ◽  
FARID A. KHWAJA ◽  
A. WAHEED
Keyword(s):  
Electrical Resistivity ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Applied Field ◽  
High Temperature Superconductor ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Current Densities

The Yb 1 Ba 2 Cu 3 O 7−x samples have been prepared by the solid state reaction using the appropriate amount of Yb 2 O 3, BaCO 3, and CuO powders and characterized them using X-ray diffraction and electrical resistivity techniques. The X-ray diffraction pattern of the sample shows an orthorhombic structure refined in the space group Pmmm. The critical current densities are calculated from magnetization measurements over a temperature range 77 K to 86 K, and in magnetic fields up to 2 KOe. The intragrain critical current density is estimated to range from 5.24 × 106 ( A/cm 2) at an applied field of 0.2 KOe to 1.01 × 106 ( A/cm 2) at an applied field of 2 KOe at T = 77 K in this sample.

Biocompatibility Research of Medicine Titanium Alloy Coating by Microarc Oxidation

2011 ◽  
Vol 189-193 ◽  
pp. 222-226
Author(s):  
Feng Biao Wang ◽  
Shi Chun Di ◽  
Jie Yu
Keyword(s):  
Titanium Alloy ◽  
Body Fluid ◽  
Oxidation Process ◽  
Microarc Oxidation ◽  
Alloy Coating ◽  
P Value ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Morphologies ◽  
Scanning Electron

A medicinal titanium alloy hydroxyapatite coating was fabricated by microarc oxidation process, and a kind standard of simulated body fluid was configured, after that the biocompatibility experiment was carried out. The soaked coatings surface morphologies were observed and analysed by scanning electron microscopy,and the coating spectra were simultaneityly researched by X-ray diffraction. The instance of degradation and precipitate were investigated,and the transformation of Ca/P value were measured.

Preparation and Electrochemical Properties of Nano Si-C Composite

2016 ◽  
Vol 852 ◽  
pp. 278-282
Author(s):  
Xiao Chen ◽  
Yun Yang ◽  
Shui Jin Yang ◽  
Chuan Qi Feng ◽  
Zai Ping Guo
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Current Density ◽  
Reversible Capacity ◽  
Testing System ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
X Ray ◽  
Initial Capacity ◽  
Scanning Electron

nanoSi-C composite was prepared using eletronspinning technique. The microstructure and morphology of the Si-C composite were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical performances of the Si-C composite were tested by battery testing system. The results showed that the Si-C composite not only behaved high initial capacity but also good cycle performances. The reversible discharge capacity could remain at 860 mAhg-1 when current density was 50 mAg-1. The rate reversible capacity is much higher than that of pure nanoSi anode at same condition.

Synthesis of submicrocrystalline TiCx–Al2O3 composites by mechanically-activated pressure-assisted self-propagating high-temperature synthesis technique

2007 ◽  
Vol 22 (10) ◽  
pp. 2700-2710 ◽  
Author(s):  
V. Gauthier ◽  
A.V. Khitev ◽  
V.A. Shcherbakov ◽  
M.F. Beaufort ◽  
P. Villechaise ◽  
...  
Keyword(s):  
Dilution Effect ◽  
X Ray Diffraction ◽  
Mechanical Method ◽  
Temperature Synthesis ◽  
Powder Mixtures ◽  
X Ray ◽  
High Temperature Synthesis ◽  
Reactant Powder ◽  
Scanning Electron ◽  
Sem Analyses

TiCx–Al2O3 composites have been synthesized by pressure-assisted combustion synthesis of (Ti + C + Al2O3) reactant powder. Different alumina contents (10–40 vol%) have been investigated to study the dilution effect on TiC microstructure. A mechanical method and a mixed chemical/mechanical method have been used to obtain (Ti + C + Al2O3) powder mixtures with different alumina distributions. Scanning electron microscopy (SEM) observations of these mixtures show that alumina is distributed inside micrometric (Ti + C) aggregates for the first method whereas alumina is located around (Ti + C) aggregates for the second one. X-ray diffraction (XRD) and SEM analyses of the composites indicate that TiCx is substoichiometric in carbon and mainly consists of submicrometric grains. A distribution of Al2O3 inside (Ti + C) aggregates is more efficient to reduce TiC grain size. For the 40 vol% Al2O3 diluted (Ti + C) mixture prepared from the mechanical route, TiCx nanocrystallites have been successfully stabilized, which demonstrates that the addition of Al2O3 diluent in a (Ti + C) mixture can be efficiently used to inhibit grain growth.

Anodization of Sputtered Titanium Films

2007 ◽  
Vol 1023 ◽  
Author(s):  
Deepak Dhawan ◽  
Suresh K. Bhargava ◽  
Wojtek Wlodarski ◽  
Kourosh Kalantar-zadeh
Keyword(s):  
Thin Films ◽  
Ammonium Fluoride ◽  
X Ray Diffraction ◽  
X Ray ◽  
Anodization Process ◽  
Titanium Thin Films ◽  
Anodized Titanium ◽  
Surface Morphologies ◽  
Micro Structures ◽  
Scanning Electron

AbstractNanoporous Ti (and TiOx) has been formed by anodization of RF sputtered titanium thin films. A solution of 1M (NH4)2SO4 (ammonium sulphate) electrolytes containing 0.5wt% (NH4)F (ammonium fluoride) was used in the anodization process. Different nano and micro structures were obtained. Voltage in a rage of 2 to 10V was employed in the process. It was observed that the magnitude of applied voltage have a significant impact in the formation of different surface morphologies with various nano/micro structures. The anodized titanium thin films were characterised using scanning electron microscopy and X-ray diffraction techniques.

Study on the Surface Morphologies of Nickel-Phosphorus Ultra-Black Films

2014 ◽  
Vol 924 ◽  
pp. 166-169 ◽  
Author(s):  
Pan Pan Yue ◽  
Yong Zhong Jin ◽  
Xu Dong Hu ◽  
Hong Yang Yan ◽  
Guo Qing Zeng
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phase Composition ◽  
Chemical Etching ◽  
Etching Time ◽  
X Ray Diffraction ◽  
X Ray ◽  
Black Films ◽  
Surface Morphologies ◽  
Scanning Electron

Ni-P ultra-black films having conical pores with the diameter of ~ 10-30 μm and the depth of ~ 15-30 μm were prepared by chemical etching of electroless plated Ni-P films using 8 mol/L nitric acid at 40 °C for 60 s. The phase composition and microstructure of the film samples were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The results show that the diameter and depth of the etching pores become larger and the flat top regions bounded by etching pores become smaller by the coalescence of adjacent pores with the increase of etching time. The surface morphologies of the etched Ni-P films are characterized by the distribution of conical pores.

scholarly journals Bimetallic Co-Based (CoM, M = Mo, Fe, Mn) Coatings for High-Efficiency Water Splitting

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 92
Author(s):  
Jadranka Milikić ◽  
Aldona Balčiūnaitė ◽  
Zita Sukackienė ◽  
Dušan Mladenović ◽  
Diogo M. F. Santos ◽  
...  
Keyword(s):  
Current Density ◽  
Potassium Hydroxide ◽  
Electroless Deposition ◽  
High Efficiency ◽  
Low Cost ◽  
Copper Substrate ◽  
X Ray Diffraction ◽  
X Ray ◽  
A Current ◽  
Scanning Electron

Bimetallic cobalt (Co)-based coatings were prepared by a facile, fast, and low-cost electroless deposition on a copper substrate (CoFe, CoMn, CoMo) and characterized by scanning electron microscopy with energy dispersive X-ray spectroscopy and X-ray diffraction analysis. Prepared coatings were thoroughly examined for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline solution (1 M potassium hydroxide, KOH) and their activity compared to that of Co and Ni coatings. All five coatings showed activity for both reactions, where CoMo and Co showed the highest activity for HER and OER, respectively. Namely, the highest HER current density was recorded at CoMo coating with low overpotential (61 mV) to reach a current density of 10 mA·cm−2. The highest OER current density was recorded at Co coating with a low Tafel slope of 60 mV·dec−1. Furthermore, these coatings proved to be stable under HER and OER polarization conditions.

scholarly journals Влияние углеродных нанотрубок на электрические и механические свойства хитозановых пленок

2022 ◽  
Vol 92 (3) ◽  
pp. 435
Author(s):  
А.М. Камалов ◽  
В.В Kодолова-Чухонцева ◽  
E.Н Дресвянина ◽  
T.П Масленникова ◽  
И.П Добровольская ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Scanning Electron Microscopy ◽  
Composite Films ◽  
X Ray Diffraction ◽  
Electronic Components ◽  
Electrical Field ◽  
Field Frequency ◽  
X Ray ◽  
Scanning Electron

Using the methods of X-ray diffraction and scanning electron microscopy, the structure of composite films based on chitosan and single-wall carbon tubes has been studied. It is shown that the introduction of carbon nanotubes leads to the ordering of the chitosan structure. Increase in concentration of nanotubes (from 0 to 3%) causes rise in the value of storage modulus from 3 to 4 GPa (DMA data), increase in electrical conductivity of samples (from 10-11 to 102 S/m), and some changes in their dielectric permittivity (from 5.5. to 26 at an electrical field frequency of 1kHz). Data on the ionic and electronic components of the conductivity of the composite film are presented.

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