scholarly journals Investigation of Inhibitory Effect of the Aloe Vera Extract on Corrosion of Aluminium Alloys

2019 ◽  
Keyword(s):  
Cyclic Voltammetry ◽  
Aluminium Alloys ◽  
Room Temperature ◽  
Aloe Vera ◽  
Scanning Speed ◽  
Inhibitory Effect ◽  
Sodium Chloride Solutions ◽  
Heat Treated ◽  
Constant Potential ◽  
Linear Polarisation

This paper considers the inhibition effect of Aloe Vera on the selected aluminium alloys in 10 % sulfuric acid and 3 % sodium chloride solutions at room temperature, using methods of potentiodynamic polarisation and cyclic voltammetry. The study involved as-cast and heat-treated 2xxx alloys, with the scanning speed of 1mV/s for linear polarisation and 50 mV/s for cyclic voltammetry. The various constant potential was applied for each tested alloy. Polarisation results indicate that the transpassivation occurs in an acid medium in case of each alloy. The obtained results indicate that Aloe vera extract acts as a cathodic inhibitor.

Spectro-Electrochemistry of Diethyldithiocarbamate Complexes of Ni(II), Pd(II) and Pt(II)

2001 ◽  
Vol 56 (2) ◽  
pp. 202-208 ◽  
Author(s):  
Şeniz Özalp Yaman ◽  
Ahmet M. Önal ◽  
Hiüseyin Isci
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Oxidation ◽  
Room Temperature ◽  
Electrochemical Behaviour ◽  
Reference Electrode ◽  
Electrochemical Process ◽  
Oxidation Peak ◽  
Complex Species ◽  
Constant Potential

Abstract The electrochemical behaviour of Na(Et2NCS2) and M(Et2NCS2)2 (M= Ni(II), Pd(II) and Pt(II); Et2NCS2-= diethyldithiocarbamate) as studied by cyclic voltammetry in the acetonitrile-( n-Bu)4NBF4 solvent-electrolyte couple at room temperature vs. Ag/Ag+ reference electrode. Constant potential electrolyses of the complexes were carried out at their first oxidation peak potentials and monitored in situ by UV-VIS spectrophotometry. The electrolysis of Ni(Et2NCS2)2 in solution yielded the dimer of the ligand, (Et2NCS2)2, and Ni2+(sol) as final products. During this electrochemical process the formation of a Ni(III) complex species as an intermediate has been observed. The electrochemical oxidation of bis(diethyldithiocarbamato) complexes of Pd(II) and Pt(II) yielded [Pd(Et2NCS2)3]+ and [Pt(Et2NCS2)3]+, respectively.

scholarly journals Effect of Substrate Plate Heating on the Microstructure and Properties of Selective Laser Melted Al-20Si-5Fe-3Cu-1Mg Alloy

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 330
Author(s):  
Pan Ma ◽  
Pengcheng Ji ◽  
Yandong Jia ◽  
Xuerong Shi ◽  
Zhishui Yu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Internal Stresses ◽  
Test Results ◽  
Laser Melting ◽  
Microstructure And Properties ◽  
Uniform Microstructure ◽  
Heat Treated ◽  
Fine Microstructure ◽  
Plate Heating ◽  
Substrate Plate

The Al-20Si-5Fe-3Cu-1Mg alloy was fabricated using selective laser melting (SLM). The microstructure and properties of the as-prepared SLM, post-treated SLM, and SLM with substrate plate heating are studied. The as-prepared SLM sample shows a non-uniform microstructure with four different phases: fcc-αAl, eutectic Al-Si, Al2MgSi, and δ-Al4FeSi2. With thermal treatment, the phases become coarser and the δ-Al4FeSi2 phase transforms partially to β-Al5FeSi. The sample produced with SLM substrate plate heating shows a relatively uniform microstructure without a distinct difference between hatch overlaps and track cores. Room temperature compression test results show that an as-prepared SLM sample reaches a maximum strength (862 MPa) compared to the heat-treated (524 MPa) and substrate plate heated samples (474 MPa) due to the presence of fine microstructure and the internal stresses. The reduction in strength of the sample produced with substrate plate heating is due to the coarsening of the microstructure, but the plastic deformation shows an improvement (20%). The present observations suggest that substrate plate heating can be effectively employed not only to minimize the internal stresses (by impacting the cooling rate of the process) but can also be used to modulate the mechanical properties in a controlled fashion.

scholarly journals Tribological Properties of Room Temperature Fluorinated Graphite Heat-Treated Under Fluorine Atmosphere

2009 ◽  
Vol 37 (1) ◽  
pp. 31-41 ◽  
Author(s):  
K. Delbé ◽  
P. Thomas ◽  
D. Himmel ◽  
J. L. Mansot ◽  
M. Dubois ◽  
...  
Keyword(s):  
Tribological Properties ◽  
Room Temperature ◽  
Fluorinated Graphite ◽  
Heat Treated ◽  
Graphite Heat ◽  
Fluorine Atmosphere

Effect of Equal-Channel Angular Pressing (ECAP) on Creep in Aluminium Alloys

2007 ◽  
Vol 539-543 ◽  
pp. 2904-2909 ◽  
Author(s):  
Vàclav Sklenička ◽  
Jiří Dvořák ◽  
Marie Kvapilová ◽  
Milan Svoboda ◽  
Petr Král ◽  
...  
Keyword(s):  
Equal Channel Angular Pressing ◽  
Aluminium Alloys ◽  
Creep Resistance ◽  
Room Temperature ◽  
Creep Behaviour ◽  
Coarse Grained ◽  
Pure Aluminium ◽  
Creep Tests ◽  
Angular Pressing ◽  
Compression Creep

This paper examines the effect of equal-channel angular pressing (ECAP) on creep behaviour of pure aluminium, binary Al-0.2wt.%Sc alloy and ternary Al-3wt.%Mg-0.2wt.%Sc alloy. The ECAP was conducted at room temperature with a die that had a 90° angle between the channels and 8 repetitive ECAP passes followed route BC. Constant stress compression creep tests were performed at 473 K and stresses ranging between 16 to 80 MPa on ECAP materials and, for comparison purposes, on the initial coarse-grained materials. The results showed that the creep resistance of the ECAP processed Al-Sc and Al-Mg-Sc alloys was markedly deteriorated with respect to unpressed coarse-grained materials.

Cyclic Voltammetry of Th(IV) in the Room-Temperature Ionic Liquid [Me3NnBu][N(SO2CF3)2]

2006 ◽  
Vol 45 (4) ◽  
pp. 1677-1682 ◽  
Author(s):  
Anand I. Bhatt ◽  
Noel W. Duffy ◽  
David Collison ◽  
Iain May ◽  
Robert G. Lewin
Keyword(s):  
Cyclic Voltammetry ◽  
Ionic Liquid ◽  
Room Temperature ◽  
Room Temperature Ionic Liquid

New Avenues in Radical Trifluoromethylselenylation with ­Trifluoromethyl Tolueneselenosulfonate

Synlett ◽  
2018 ◽  
Vol 30 (07) ◽  
pp. 777-782 ◽  
Author(s):  
Clément Ghiazza ◽  
Cyrille Monnereau ◽  
Lhoussain Khrouz ◽  
Maurice Médebielle ◽  
Thierry Billard ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Transition Metal ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Room Temperature ◽  
Diazonium Salts ◽  
Metal Free ◽  
Luminescence Measurement ◽  
Stable Reagent ◽  
Shelf Stable

We demonstrated that the shelf-stable reagent trifluoromethyl tolueneselenosulfonate can be involved in radical trifluoromethylselenylation. Upon visible-light irradiation, the homolysis of the reagent could take place at room temperature. This finding is explored for unprecedented C(sp2)–SeCF3 and C(sp3)–SeCF3 processes under transition-metal-free conditions. Mechanistic investigations, including cyclic voltammetry, luminescence measurement, and EPR studies, allowed the proposal of plausible mechanisms.1 Introduction.2 Reactivity of Reagent I with Diazonium Salts3 Reactivity of Reagent I with Alkenes and Alkynes4 Conclusion

Obtention of an Al-Based Composite Material by Direct Fusion of Used Beverage Cans

2012 ◽  
Vol 706-709 ◽  
pp. 271-276 ◽  
Author(s):  
Claudia Carrasco ◽  
C. Montalba ◽  
Carlos Camurri
Keyword(s):  
Composite Material ◽  
Aluminium Alloys ◽  
Metal Matrix ◽  
Mechanical Analysis ◽  
Heat Treated ◽  
Structural Applications ◽  
Metal Matrix Composite Material ◽  
Direct Fusion ◽  
Scanning Electron

In the present study, the fabrication of an Al-based metal matrix composite material obtained directly from the melting of the aluminium used beverage cans in a modified rheocasting process is presented. The analysed operational condition is the shear rate applied to the bath and its influence on the properties of the obtained samples. Additionally, samples were heat treated at two different times. The characterization of the phases obtained in Al-based MMC was made by means of metallography, scanning electron microscopy with energy dispersive spectroscopy and electron microprobe with wavelength dispersion spectroscopy. The results show that some constituents were formed during the fabrication process of the MMC, mainly Al6(Fe, Mn), which are partially transformed during the heat treatment. Additionally, samples were evaluated using dynamic mechanical analysis, and the results suggest that the obtained MMC could have very good mechanical properties, similar or superior to the aluminium alloys commonly used for structural applications such as 6XXX family.

Modification in Texture of Magnesium by the Addition of Rare Earth Elements and its Influence on Mechanical Properties

2012 ◽  
Vol 736 ◽  
pp. 307-315 ◽  
Author(s):  
Murugavel Suresh ◽  
Satyam Suwas
Keyword(s):  
Mechanical Properties ◽  
Rare Earth ◽  
Magnesium Alloys ◽  
Aluminium Alloys ◽  
Room Temperature ◽  
Main Obstacle ◽  
Rare Earth Addition ◽  
Structural Applications ◽  
Re Elements ◽  
The Relationship

Mg alloys show limited room temperature formability compared to its lightweight counterpart aluminium alloys, which is a main obstacle in using this metal for most of the structural applications. However, it is known that grain refinement and texture control are the two possibilities for the improvement of formability of magnesium alloys. Amongst the approaches attempted for the texture weakening, additions through of rare-earth (RE) elements have been found most effective. The relationship between the texture and ductility is well established. In this paper, the effect of rare earth addition on texture weakening has been summarized for various magnesium alloys under the two most common modes of deformation methods.

scholarly journals Facile and reproducible method of stabilizing $$\hbox {Bi}_2\hbox {O}_3$$ phases confined in nanocrystallites embedded in amorphous matrix

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tomasz K. Pietrzak ◽  
Agata Jarocka ◽  
Cezariusz Jastrzębski ◽  
Tomasz Płociński ◽  
Marek Wasiucionek ◽  
...  
Keyword(s):  
Room Temperature ◽  
Amorphous Matrix ◽  
Glassy Matrix ◽  
Process Conditions ◽  
Oxide Ion Conductivity ◽  
Heat Treated ◽  
Reproducible Method ◽  
Glassy Materials ◽  
Quenching Method ◽  
Oxide Ion

AbstractBismuth sesquioxide ($$\hbox {Bi}_2\hbox {O}_3$$ Bi 2 O 3 ) draws much attention due to wide variety of phases in which it exists depending on the temperature. Among them, $$\delta$$ δ phase is specially interesting because of its high oxide ion conductivity and prospects of applications as an electrolyte in fuel cells. Unfortunately, it is stable only in a narrow temperature range ca. 730–830 $$^{\circ }$$ ∘ C. Our group has developed a facile and reproducible two-stage method of stabilizing $$\hbox {Bi}_2\hbox {O}_3$$ Bi 2 O 3 crystalline phases confined in nanocrystallites embedded in amorphous matrix. In the first stage, glassy materials were obtained by a routine melt-quenching method: pure $$\hbox {Bi}_2\hbox {O}_3$$ Bi 2 O 3 powders were melted in porcelain crucibles and fast-cooled down to room temperature. In the second step, the materials were appropriately heat-treated to induce formation of crystallites of $$\beta$$ β , $$\delta$$ δ or $$\gamma$$ γ $$\hbox {Bi}_2\hbox {O}_3$$ Bi 2 O 3 phases confined in a glassy matrix, depending on the process conditions. It was found out that the vitrification of the initial $$\hbox {Bi}_2\hbox {O}_3$$ Bi 2 O 3 and the subsequent nanocrystallization were unexpectedly possible due to the presence of some Al, and Si impurities from the crucibles. Systematic DTA, XRD, optical, Raman and SEM/EDS studies were carried out to investigate the influence of the syntheses processes and allowed us to determine conditions under which the particular phases appear and remain stable down to room temperature.

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