scholarly journals Effect of Aluminum Addition on the Microstructure and Properties of Non-Eutectic Sn-20Bi Solder Alloys

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1194 ◽  
Author(s):  
Yang ◽  
Li ◽  
Li ◽  
Feng ◽  
Wu ◽  
...  
Keyword(s):  
Test Results ◽  
X Ray Diffraction ◽  
Solder Alloys ◽  
X Ray ◽  
Eds Analysis ◽  
Maximum Value ◽  
Cu Substrates ◽  
Microstructure Morphology ◽  
Hardness Change ◽  
Spreading Test

This study investigates the effect of aluminum (Al) on the microstructure, micro-hardness, and wettability of environmentally friendly Sn-20Bi-xAl (x = 0, 0.1, 0.3, 0.5 (wt.%)) solder alloys. Scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) analysis, and X-ray diffraction (XRD), were used to identify the microstructure morphology and composition. The spreading area and contact angle of the Sn-20Bi-xAl alloys on Cu substrates were used to measure the wettability of solder alloys. The results indicate that Al increased the hardness to a maximum value of ~27.1 HV for x = 0.5. When the content of Al was more than 0.3 wt.%, the hardness change value gradually flattened. From the spreading test results, Al reduced the wettability of solder alloys. When the content of Al was 0.1 wt.%, the change was slight. When more than 0.3 wt.%, the wettability of Sn-20Bi-xAl solder alloys sharply dropped. The corrosion resistance of Sn-20Bi-0.1Al alloy was the best, and the corrosion rate was at the lowest value at 0.092 mm/a due to the dense corrosion products.

scholarly journals Mining Wastes of an Albite Deposit as Raw Materials for Vitrified Mullite Ceramics

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 232
Author(s):  
Pedro J. Sánchez-Soto ◽  
Eduardo Garzón ◽  
Luis Pérez-Villarejo ◽  
George N. Angelopoulos ◽  
Dolores Eliche-Quesada
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Phase Evolution ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Mining Wastes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Maximum Value

In this work, an examination of mining wastes of an albite deposit in south Spain was carried out using X-ray Fluorescence (XRF), X-ray diffraction (XRD), particle size analysis, thermo-dilatometry and Differential Thermal Analysis (DTA) and Thermogravimetric (TG) analysis, followed by the determination of the main ceramic properties. The albite content in two selected samples was high (65–40 wt. %), accompanied by quartz (25–40 wt. %) and other minor minerals identified by XRD, mainly kaolinite, in agreement with the high content of silica and alumina determined by XRF. The content of Na2O was in the range 5.44–3.09 wt. %, being associated with albite. The iron content was very low (<0.75 wt. %). The kaolinite content in the waste was estimated from ~8 to 32 wt. %. The particle size analysis indicated values of 11–31 wt. % of particles <63 µm. The ceramic properties of fired samples (1000–1350 °C) showed progressive shrinkage by the thermal effect, with water absorption and open porosity almost at zero at 1200–1250 °C. At 1200 °C, the bulk density reached a maximum value of 2.38 g/cm3. An abrupt change in the phase evolution by XRD was found from 1150 to 1200 °C, with the disappearance of albite by melting in accordance with the predictions of the phase diagram SiO2-Al2O3-Na2O and the system albite-quartz. These fired materials contained as main crystalline phases quartz and mullite. Quartz was present in the raw samples and mullite was formed by decomposition of kaolinite. The observation of mullite forming needle-shape crystals was revealed by Scanning Electron Microscopy (SEM). The formation of fully densified and vitrified mullite materials by firing treatments was demonstrated.

Transient liquid phase bonding of Cu and Al using metallic particles interlayers

2021 ◽  
pp. 095440542098823
Author(s):  
Alireza Zaheri ◽  
Mohammadreza Farahani ◽  
Alireza Sadeghi ◽  
Naser Souri
Keyword(s):  
Liquid Phase ◽  
Mechanical Test ◽  
Transient Liquid Phase ◽  
Transient Liquid Phase Bonding ◽  
Joint Interface ◽  
Test Results ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metallic Particles ◽  
Powder Interlayer

The bonding strength, and microstructures of Cu and Al couples using metallic powders as interlayer during transient liquid phase bonding (TLP bonding) were investigated. The interfacial morphologies and microstructures were studied by scanning electron microscopy equipped with energy dispersive X-ray spectroscopy, and X-ray diffraction. First, to explore the optimum bonding time and temperature, nine samples were bonded without interlayers in a vacuum condition. Mechanical test results indicated that bonding at 560°C in 20 min returns the highest bond strength (84% of Al). This bonding condition was used to join ten samples with powder interlayers. Powders were prepared by mixing different combinations of Cu, Al (+Fe nanoparticles) and Zn. In the bonding zone, different Cu9Al4, CuAl, and CuAl2 intermetallic co-precipitate. The strongest bonding is formed in the sample with the 70Al (+Fe)-30Cu powder interlayer. Powder interlayers present thinner and more uniform intermetallic layers at the joint interface.

scholarly journals Effect of Molybdenum Content on the Corrosion and Microstructure of Low-Ni, Co-Free Maraging Steels

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 852
Author(s):  
Asiful H. Seikh ◽  
Hossam Halfa ◽  
Mahmoud S. Soliman
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Microstructural Analysis ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Alloying Element ◽  
X Ray ◽  
Maraging Steels ◽  
Eds Analysis ◽  
Electroslag Refining

Molybdenum (Mo) is an important alloying element in maraging steels. In this study, we altered the Mo concentration during the production of four cobalt-free maraging steels using an electroslag refining process. The microstructure of the four forged maraging steels was evaluated to examine phase contents by optical microscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis. Additionally, we assessed the corrosion resistance of the newly developed alloys in 3.5% NaCl solution and 1 M H2SO4 solution through potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. Furthermore, we performed SEM and energy-dispersive spectroscopy (EDS) analysis after corrosion to assess changes in microstructure and Raman spectroscopy to identify the presence of phases on the electrode surface. The microstructural analysis shows that the formation of retained austenite increases with increasing Mo concentrations. It is found from corrosion study that increasing Mo concentration up to 4.6% increased the corrosion resistance of the steel. However, further increase in Mo concentration reduces the corrosion resistance.

Study on Phases and Thermoelectric Properties of Bulk Fe4Sb12 and Fe3CoSb12 Prepared by Milling and Sintering

2011 ◽  
Vol 121-126 ◽  
pp. 1526-1529
Author(s):  
Ke Gao Liu ◽  
Jing Li
Keyword(s):  
Thermoelectric Properties ◽  
Impurity Phase ◽  
Semiconductor Materials ◽  
Thermal Constant ◽  
X Ray Diffraction ◽  
X Ray ◽  
Seebeck Coefficients ◽  
Maximum Value ◽  
Type Semiconductor ◽  
P Type

Bulk Fe4Sb12 and Fe3CoSb12 were prepared by sintering at 600 °C. The phases of samples were analyzed by X-ray diffraction and their thermoelectric properties were tested by electric constant instrument and laser thermal constant instrument. Experimental results show that, the major phases of bulk samples are skutterudite with impurity phase FeSb2. The electric resistivities of the samples increase with temperature rising at 100~500 °C. The bulk samples are P-type semiconductor materials. The Seebeck coefficients of the bulk Fe4Sb12 are higher than those of bulk Fe3CoSb12 samples at 100~200 °C but lower at 300~500 °C. The power factor of the bulk Fe4Sb12 samples decreases with temperature rising while that of bulk Fe3CoSb12 samples increases with temperature rising at 100~500 °C. The thermal conductivities of the bulk Fe4Sb12 samples are relatively higher than those of and Fe3CoSb12, which maximum value is up to 0.0974 Wm-1K-1. The ZT value of bulk Fe3CoSb12 increases with temperature rising at 100~500 °C, the maximum value is up to 0.031.The ZT values of the bulk Fe4Sb12 samples are higher than those of bulk Fe3CoSb12 at 100~300 °C while lower at 400~500 °C.

scholarly journals Alkali Activation of Oil Shale Ash Based Ceramics

2012 ◽  
Vol 9 (3) ◽  
pp. 1373-1388 ◽  
Author(s):  
A. Hamadi ◽  
K. Nabih
Keyword(s):  
Oil Shale ◽  
Experimental Approach ◽  
Acid Leaching ◽  
Alkali Activation ◽  
X Ray Diffraction ◽  
Oil Shale Ash ◽  
X Ray ◽  
Eds Analysis ◽  
Shale Ash ◽  
Activating Solution

Timahdit oil shale was subjected to firing transformation via ceramics processing followed by alkali activation to synthesis a materials combining the mechanical properties of ceramics and Zeolites. The mineralogical transformations during firing oil shale have been studied. The main crystalline phases found in oil shale ash (OSA) were wollastonite, gehlenite and augite. Modified oil shale ash (MOSA) was obtained with HNO3acid-leaching in the aim to diminish Ca content. Our experimental approach required a NaOH alkaline activating solution with different concentrations (0.5; 1; 2; 4; 6 and 8M). In our study, X-ray diffraction (XDR), Fourier transform infrared (FTIR) and SEM/EDS analysis were used to evaluate the effect of alkali activation on the structural arrangement of the starting materials (OSA and MOSA) in our study. The quantity and the type of the produced zeolites depended critically on the starting materials and on the NaOH concentration.

Corrosion inhibition of organic amine on Q235 steel in ammonium sulfate slurry of ammonia flue gas desulfurization system

2017 ◽  
Vol 64 (4) ◽  
pp. 432-442
Author(s):  
Zhouyang Lian ◽  
Zhengwei Luo ◽  
Lirui Yuan ◽  
Mulin Guo ◽  
Wuji Wei ◽  
...  
Keyword(s):  
Ammonium Sulfate ◽  
Flue Gas ◽  
Inhibition Efficiency ◽  
Flue Gas Desulfurization ◽  
Protective Film ◽  
X Ray Diffraction ◽  
Content Type ◽  
X Ray ◽  
Q235 Steel ◽  
Maximum Value

Purpose This paper aims to evaluate diethylenetriamine (DETA) as an inhibitor on Q235 (Gr. D) steel in ammonia flue gas desulfurization (AFGD) system. Design/methodology/approach This research was carried out by weight loss, electrochemical measurements, scanning electron microscopy and X-ray photoelectron spectrometry. The effects of DETA on crystallization of ammonium sulfate and its co-crystallization were also investigated by X-ray diffraction and infrared spectroscopy. Findings The inhibition efficiency of DETA reached a maximum value of 98.96 per cent. DETA is postulated to adsorb on Q235 steel surface, resulting in the formation of a protective film by the accumulation of many flat particles, and the thickness of protective film is 8 μm. DETA had no effect on the crystallization of ammonium sulfate product. Originality/value DETA can be used in AFGD system as an inhibitor to protect the equipment well.

Effect of ultra-thin Cu underlayer on the magnetic properties of Ni80Fe50 / Fe50Mn50 films

1999 ◽  
Vol 562 ◽  
Author(s):  
C. Liu ◽  
L. Shen ◽  
H. Jiang ◽  
D. Yang ◽  
G. Wu ◽  
...  
Keyword(s):  
Thin Film ◽  
Atomic Force Microscopy ◽  
Exchange Bias ◽  
Film Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Maximum Value ◽  
Film Roughness

ABSTRACTThe Ni80Fe20/Fe50Mn50,thin film system exhibits exchange bias behavior. Here a systematic study of the effect of atomic-scale thin film roughness on coercivity and exchange bias is presented. Cu (t) / Ta (100 Å) / Ni80Fe20 (100 Å) / Fe50Mno50 (200 Å) / Ta (200 Å) with variable thickness, t, of the Cu underlayer were DC sputtered on Si (100) substrates. The Cu underlayer defines the initial roughness that is transferred to the film material since the film grows conformal to the initial morphology. Atomic Force Microscopy and X-ray diffraction were used to study the morphology and texture of the films. Morphological characterization is then correlated with magnetometer measurements. Atomic Force Microscopy shows that the root mean square value of the film roughness exhibits a maximum of 2.5 Å at t = 2.4 Å. X-ray diffraction spectra show the films are polycrystalline with fcc (111) texture and the Fe50Mn50 (111) peak intensity decreases monotonically with increasing Cu thickness, t. Without a Cu underlayer, the values of the coercivity and loop shift are, Hc = 12 Oe and Hp = 56 Oe, respectively. Both the coercivity and loop shift change with Cu underlayer thickness. The coercivity reaches a maximum value of Hc= 36 Oe at t = 4 Å. The loop shift exhibits an initial increase with t, reaches a maximum value of HP = 107 Oe at t = 2.4 Å, followed by a decrease with greater Cu thickness. These results show that a tiny increase in the film roughness has a huge effect on the exchange bias magnitude.

Effect of nano Al2O3 coated Ag reinforced Cu matrix nanocomposites on mechanical and tribological behavior synthesis by P/M technique

2020 ◽  
Vol 54 (30) ◽  
pp. 4921-4928
Author(s):  
A Mohamed ◽  
MM Mohammed ◽  
AF Ibrahim ◽  
Omyma A El-Kady
Keyword(s):  
Wear Behavior ◽  
Composite Coatings ◽  
Microstructural Analysis ◽  
Wear Test ◽  
Test Results ◽  
X Ray Diffraction ◽  
X Ray ◽  
Average Hardness ◽  
Ag Particles ◽  
Matrix Nanocomposites

In this study, copper powder was reinforced with different weight percentages of Al2O3 particles (0, 5, 10, and 15 wt.% Al2O3 coated Ag) to produce Cu-Al2O3 composites by mechanical alloying and uniaxial cold pressing/sintering route. Electro-less deposition was used to coat Al2O3 particles with Ag. The microstructure of the consolidated samples was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) elemental mapping. The porosity, microhardness, and wear behavior of the consolidated samples were also investigated as a function of Al2O3 content. The EDX mapping images reveal that the Al2O3 reinforcement particles were homogeneously distributed into the Cu matrix. Microstructural analysis shows that the addition of Al2O3 coated Ag particles improves density of the composites coating. SEM micrographs result shows that slight porosities exist in the composites produced. Furthermore, the average hardness of the composite coatings varies from 72.3 to 187.6 HV as Al2O3 content increases from 0 to 15 wt.%. The wear test results showed that the composite with higher Al2O3 content 15 wt.% showed the best wear resistance.

A Novel Approach to Unzipped Tubes Synthesis Using Sulfanilic Acid as the Backbone Amino Acid

2019 ◽  
Vol 57 ◽  
pp. 17-30
Author(s):  
Christopher Narh ◽  
Charles Frimpong ◽  
Qu Fu Wei
Keyword(s):  
Differential Scanning Calorimetry ◽  
Bond Formation ◽  
Sulfanilic Acid ◽  
Test Results ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Torsion Angles ◽  
X Ray ◽  
Novel Approach ◽  
Hydrophobic Peptide

In this research, unzipped sulfanilic acid inspired hydrophobic peptide tube was synthesis by increasing the polarity of sulfanilic acid through nucleophilic attachment of aniline which then provided two reactive sites at the S-terminus. These two sites were then attached with the N-terminal of valine and alanine respectively at an intensity of 1000-1600 of 11 2θ (°). Through π-π stacking at the side chains, the opened ended peptide was linearly arranged to form the unzipped tube. Fourier transform infrared spectroscopy (FTIR) confirm the amine bond formation whiles X-ray diffraction test results confirmed D-spacing 7.36 and 4.44 corresponding 2θ (°)12 and 19.97 respectively whiles the torsion angles (Ø2) conformations was between-150.5°and-169.2° and-2 between-129.0° and-150.6°. The Thermogravimetric analysis result showed an increase in the rigidity of the bond with an increasing intensity. Finally, Differential scanning calorimetry (DSC) test was carried out to confirm the crystallinity of the structure. Keywords: Sulfanilic acid, hydrophobic Peptide, Unzipped tubes, Nanomaterial

scholarly journals Quantitative Evaluation of Crystalline and Amorphous Phases in Clay-Based Cordierite Ceramic

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1122
Author(s):  
Zdeněk Klika ◽  
Marta Valášková ◽  
Lucie Bartoňová ◽  
Petra Maierová
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Chemical Analysis ◽  
Test Results ◽  
Mineral Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amorphous Phases ◽  
Cordierite Ceramic ◽  
Scanning Electron

An innovative chemical quantitative mineral analysis (CQMA) was successfully tested on a cordierite-based clay ceramic sample to quantify crystalline and amorphous components. The accuracy of this method was demonstrated on an added module to the CQMA program that used oxide formulas of amorphous phases obtained by energy dispersive X-ray spectroscopy (EDS) microprobe chemical analysis. This CQMA method was tested for three variants calculated using chemical analysis, i.e., X-ray diffraction (XRD) identification of crystalline (cordierite and enstatite) and amorphous phases by scanning electron microscopy (SEM)/EDS texture and microanalyses. The test results from CQMA suggest their application possibilities as well as the limits of their utilization.

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