Effects of Ca and RE Additions on the Precipitation and Microstructure of As-Cast AZ91 Alloy

2017 ◽  
Vol 865 ◽  
pp. 30-35 ◽  
Author(s):  
Li Fu ◽  
Qi Chi Le ◽  
Pei Li Gou ◽  
Xi Bo Wang ◽  
Xuan Liu
Keyword(s):  
Intermetallic Compound ◽  
Grain Boundaries ◽  
Intermetallic Compounds ◽  
Lamellar Structure ◽  
Az91 Alloy ◽  
Sem Images ◽  
Xrd Pattern ◽  
Microstructure Changes ◽  
Polygonal Structure ◽  
Cast Alloys

The effect of Ca and RE metal additions on the precipitation and microstructure of as-cast AZ91 alloy was systematically investigated. It was found that Ca and RE additions could result in phase and microstructure changes. The XRD pattern showed the crystallite phase of as-cast AZ91 alloys consists of α-Mg matrix and β-Mg17Al12, however, after adding 1.5wt. % Ca and 0.8wt. % RE (0.5wt. % Sm and 0.3wt. % La), peaks coincident with Al2Ca, Al2Sm and Al11La3 intermetallic compounds were found, suggesting the generation of relative precipitates. The SEM images indicated that in as-cast alloys, the Al2Ca intermetallic compound was located at grain boundaries with a lamellar structure, and the Al2Sm intermetallic compound was homogeneously distributed in the α-Mg matrix or near the grain boundaries with a polygonal structure, and the Al11La3 intermetallic compound was located at grain boundaries with a needlelike structure. These intermetallic compounds could reduce the amount of β-Mg17Al12 and refine the microstructure of as-cast AZ91 alloy.

scholarly journals Antitumor Potential of Green Synthesized ZnONPs Using Root Extract of Withania somnifera against Human Breast Cancer Cell Line

Separations ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 8
Author(s):  
Kollur Shiva Prasad ◽  
Shashanka K Prasad ◽  
Ravindra Veerapur ◽  
Ghada Lamraoui ◽  
Ashwini Prasad ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Line ◽  
Withania Somnifera ◽  
Root Extract ◽  
Dependent Manner ◽  
Sem Images ◽  
Xrd Pattern ◽  
Transmission Electron

Herein we report the synthesis of zinc oxide nanoparticles (ZnONPs) using Withania somnifera root extract (WSE) as an effective chelating agent. The microscopic techniques viz., X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and selected area electron diffraction (SAED) were employed to analyze the as-obtained ZnONPs. The crystalline planes observed from the XRD pattern agrees with the hexagonal wurtzite structure of the as-prepared ZnONPs. The aggregations and agglomerations observed in the SEM images indicated that the size of the as-prepared ZnONPs was between 30 and 43 nm. The interplanar distance between the lattice fringes observed in the HRTEM image was found to be 0.253 nm, which is in good agreement with the (100) plane obtained in the XRD pattern. Furthermore, the anti-breast cancer cytotoxic evaluation was carried out using the MCF-7 cell line, and the results showed significant cytotoxic effects in a dose-dependent manner.

scholarly journals Heat Treatment-Induced Microstructure and Property Evolution of Mg/Al Intermetallic Compound Coatings Prepared by Al Electrodeposition on Mg Alloy from Molten Salt Electrolytes

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1407
Author(s):  
Tianyu Yao ◽  
Kui Wang ◽  
Haiyan Yang ◽  
Haiyan Jiang ◽  
Jie Wei ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Intermetallic Compound ◽  
Intermetallic Compounds ◽  
Mg Alloy ◽  
X Ray Diffraction ◽  
Electron Backscattered Diffraction ◽  
Alloy Matrix ◽  
Comprehensive Properties ◽  
Compound Coatings ◽  
Compound Coating

A method of forming an Mg/Al intermetallic compound coating enriched with Mg17Al12 and Mg2Al3 was developed by heat treatment of electrodeposition Al coatings on Mg alloy at 350 °C. The composition of the Mg/Al intermetallic compounds could be tuned by changing the thickness of the Zn immersion layer. The morphology and composition of the Mg/Al intermetallic compound coatings were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and electron backscattered diffraction (EBSD). Nanomechanical properties were investigated via nano-hardness (nHV) and the elastic modulus (EIT), and the corrosion behavior was studied through hydrogen evolution and potentiodynamic (PD) polarization. The compact and uniform Al coating was electrodeposited on the Zn-immersed AZ91D substrate. After heat treatment, Mg2Al3 and Mg17Al12 phases formed, and as the thickness of the Zn layer increased from 0.2 to 1.8 μm, the ratio of Mg2Al3 and Mg17Al12 varied from 1:1 to 4:1. The nano-hardness increased to 2.4 ± 0.5 GPa and further improved to 3.5 ± 0.1 GPa. The Mg/Al intermetallic compound coating exhibited excellent corrosion resistance and had a prominent effect on the protection of the Mg alloy matrix. The control over the ratio of intermetallic compounds by varying the thickness of the Zn immersion layer can be an effective approach to achieve the optimal comprehensive performance. As the Zn immersion time was 4 min, the obtained intermetallic compounds had relatively excellent comprehensive properties.

scholarly journals Structural and Electrical Studies on ZnO-Based Thin Films by Laser Irradiation

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Shanyue Zhao ◽  
Yinqun Hua ◽  
Ruifang Chen ◽  
Jian Zhang ◽  
Ping Ji
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Electrical Properties ◽  
Grain Boundaries ◽  
Laser Irradiation ◽  
Nonlinear Coefficient ◽  
Acceptor State ◽  
Xrd Pattern ◽  
Electrical Studies ◽  
Structural And Electrical Properties

The effects of laser irradiation on the structural and electrical properties of ZnO-based thin films were investigated. The XRD pattern shows that the thin films were highly textured along thec-axis and perpendicular to the surface of the substrate. Raman spectra reveal that Bi2O3segregates mainly at ZnO-ZnO grain boundaries. After laser irradiation processing, the grain size of the film was reduced significantly, and the intrinsic atomic defects of grain boundaries and Bi element segregated at the grain boundary were interacted frequently and formed the composite defects of acceptor state. The nonlinear coefficient increased to 24.31 and the breakdown voltage reduced to 5.34 V.

INTERMETALLIC COMPOUND AlxTi – ARE PROMISING MATERIAL FOR HIGH ELEVATED TEMPERATURES (review) Part 1. The crystaline structure and properties of the intermetallic compound Al2Ti

2021 ◽  
pp. 28-43
Author(s):  
N.A. Nochovnaya ◽  
◽  
V.I. Ivanov ◽  
L.Yu. Avilochev ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Intermetallic Compound ◽  
Lamellar Structure ◽  
Power Plants ◽  
Elevated Temperatures ◽  
Texture Formation ◽  
Structure And Properties ◽  
High Temperature Alloys ◽  
Transformation Mechanisms ◽  
Increased Strength

The Al2Ti intermetallic compound is the most promising base for high-temperature alloys designed for advanced power plants. This work provides an overview of the structures of binary alloys concerning to the Ti–Al system, as well as the phase transformation mechanisms and the peculiarities of plastic deformation of alloys. The alloys which phase composition is represented by a mixture of r-Al2Ti+γ-TiAl with a lamellar structure show anomalous mechanical properties depending on texture formation and grain size. These alloys possess increased strength and decreased plasticity at elevated temperatures.

CRYSTALLINE STRUCTURE AND PHYSICAL PROPERTIES OF UCo2Al3

2004 ◽  
Vol 18 (30) ◽  
pp. 3905-3914
Author(s):  
E. VERDÍN ◽  
R. ESCUDERO
Keyword(s):  
Intermetallic Compound ◽  
Physical Properties ◽  
Single Crystal ◽  
Intermetallic Compounds ◽  
Heavy Fermion ◽  
Ferromagnetic Transition ◽  
Crystallographic Characteristics ◽  
Heavy Fermion Behavior ◽  
Small Single Crystal ◽  
Weak Ferromagnetic

Some intermetallic compounds which contain uranium or cerium present heavy fermion characteristics. Take, for example, in the UM 2 Al 3 ( M = Pd , Ni ) family, superconductivity and magnetism coexist and present heavy fermion behavior. This work presents the crystallographic characteristics and physical properties of a new compound of this family; the intermetallic compound UCo 2 Al 3. Our initial crystallographic studies performed in a small single crystal show that the structure is hexagonal and similar to the UNi 2 Al 3 and UPd 2 Al 3 parent compounds. The space group is P6/mmm with a=5.125 Å and c=4.167 Å crystalline parameters. Measurements of resistivity and magnetization performed on the single crystal reveal that the compound is not superconducting when measured at about 1.8 K. The compound is highly anisotropic and features related to Kondo-like behavior are observed. A weak ferromagnetic transition is observed at a temperature of about 20 K.

Morphology of wetting reactions of SnPb alloys on Cu as a function of alloy composition

1998 ◽  
Vol 13 (1) ◽  
pp. 37-44 ◽  
Author(s):  
C. Y. Liu ◽  
K. N. Tu
Keyword(s):  
Free Energy ◽  
Intermetallic Compound ◽  
Intermetallic Compounds ◽  
Driving Force ◽  
Alloy Composition ◽  
Wetting Angle ◽  
Compound Formation ◽  
Side Band ◽  
Intermetallic Compound Formation ◽  
Pure Sn

We have investigated the wetting angle, side band growth, and intermetallic compound formation of seven SnPb alloys on Cu ranging from pure Sn to pure Pb. The wetting angle has a minimum near the middle composition and increases toward pure Sn and pure Pb, but the side band growth has a maximum near the middle composition. The intermetallic compounds formed are Cu6Sn5 and Cu3Sn for the eutectic and high-Sn alloys, yet for the high-Pb alloys, only Cu3Sn can be detected. While no intermetallic compound forms between Cu and pure Pb, the latter nevertheless wets the former with an angle of 115°. The driving force of a wetting reaction, which may be affected by the free energy gain in compound formation, is discussed by assuming that rate of compound formation is fast.

Hydrogen Diffusivity and Solubility in Internally Oxidized Pd0.97Zr0.03 and Pd0.97Nb0.03 Alloys

2010 ◽  
Vol 297-301 ◽  
pp. 715-721
Author(s):  
E.R. Lagreca ◽  
Viviane M. Azambuja ◽  
Dílson S. dos Santos
Keyword(s):  
Diffusion Coefficient ◽  
Grain Boundaries ◽  
Hydrogen Pressure ◽  
Hydrogen Diffusion ◽  
Gas Permeation ◽  
Hydrogen Diffusivity ◽  
Sem Images ◽  
Conventional Furnace ◽  
Hydrogen Diffusion Coefficient ◽  
Preferential Segregation

Internally oxidized (I.O.) Pd0.97Zr0.03 and Pd0.97Nb0.03 alloys were submitted to gas permeation tests with temperatures in the range of 473-873 K. The internal oxidation was kept in a conventional furnace at 1073 K for 24 hours in air contact. The formation of nano-oxides, ZrO2 and Nb2O5, dispersed in the Pd matrix was observed. SEM images showed a preferential segregation of these oxides in the grain boundaries. It was observed that the diffusion coefficient in the sample containing Nb oxide was smaller than that in the Pd-Zr oxide. The effect of hydrogen pressure was investigated in the Pd-Nb samples. It was observed that the hydrogen diffusion coefficient increases with increasing the pressure. The hydrogen solubility is bigger for the Pd-Zr internally oxidized. This effect is attributed to the Zr nanoxides, which are smaller than Pd-Nb precipitates and then offer more interface for trapping the hydrogen.

scholarly journals Special Issue “Intermetallic Compound”

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1067
Author(s):  
Jacek Ćwik
Keyword(s):  
Intermetallic Compound ◽  
Physical Properties ◽  
Intermetallic Compounds ◽  
Special Issue

This Special Issue collects ten articles related to the broadly understood physical properties of intermetallic compounds [...]

scholarly journals Effect of TiO2 Concentration on Thermal Stability and Dielectric Properties of (PANI)1-x(TiO2)x Nanocomposites

2019 ◽  
Vol 31 (4) ◽  
pp. 855-859
Author(s):  
Ajay Kumar Sharma ◽  
Praveen Kumar Jain ◽  
Rishi Vyas ◽  
Vipin Kumar Jain
Keyword(s):  
Thermal Stability ◽  
Dielectric Properties ◽  
Optoelectronic Devices ◽  
Chemical Properties ◽  
Rutile Phase ◽  
Sem Images ◽  
Xrd Pattern ◽  
The Matrix ◽  
Structural Surface ◽  
And Chemical Properties

The current paper deals with investigation of (PANI)1-x(TiO2)x nanocomposites to explore possible material for optoelectronic devices. To investigate the effect of TiO2 concentration on structural, surface morphology and chemical properties of PANI, samples were characterized by XRD, FTIR, SEM and Raman spectroscopy. The XRD pattern evidence the presence of a blend of anatase and rutile phase of TiO2 within the PANI matrix which shows amorphous nature of the matrix. FTIR and Raman spectra confirm the formation of PANI/TiO2 nanocomposites. SEM images show the appearance of lumps into smooth PANI samples with addition of TiO2 nanoparticles. The thermal and dielectric properties were studied using TGA and Impedance analyzer, respectively. The results showed that the addition of TiO2 improves the thermal stability, which clearly shows its potential application in optoelectronic devices.

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