scholarly journals Mechanical and electrical properties of ternary Ag-Bi-Ga system at 250 °C

10.30544/309 ◽  
2017 ◽  
Vol 23 (3) ◽  
pp. 227-240
Author(s):  
Duško Minić ◽  
Dragan Manasijević ◽  
Yong Du ◽  
Pavel Brož ◽  
Vladan Ćosović ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Energy Dispersive Spectrometry ◽  
Thermodynamic Assessment ◽  
Vickers Microhardness ◽  
Brinell Hardness ◽  
Hardness Test ◽  
X Ray ◽  
Mechanical And Electrical Properties ◽  
Comparative Review ◽  
The Individual

This paper presents a comparative review of the experimental and thermodynamic assessment of a ternary Ag-Bi-Ga system. An isothermal section at 250 °C was calculated using optimized thermodynamic data for the constitutive binaries. Microstructures and phase compositions of studied alloys were analyzed by scanning electron microscopy in combination with energy dispersive spectrometry and X-ray powder diffraction technique. The obtained experimental results were found to support the predicted phase equilibria rather well. The hardness of alloys from three vertical sections (Bi-AgGa, Ag-BiGa, and Ga-AgBi) was determined using Brinell hardness test while the hardness of the individual identified phases was determined using Vickers microhardness test. Additional electrical conductivity measurements were carried out on the same alloy samples. Based on the experimentally obtained results iso-lines of Brinell hardness and electrical conductivity for the entire compositional range were calculated.

scholarly journals Effect of chemical composition on microstructure, hardness and electrical conductivity profiles of the Bi-Cu-Ga alloys at 100 °C

10.30544/211 ◽  
2016 ◽  
Vol 22 (3) ◽  
pp. 179-192
Author(s):  
Dejan Gurešić ◽  
Nadežda Talijan ◽  
Vladan Ćosović ◽  
Dušan Milisavljević ◽  
Aleksandar Đorđević ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Experimental Investigation ◽  
Isothermal Section ◽  
Brinell Hardness ◽  
Microstructural Analysis ◽  
Composition Analysis ◽  
Conductivity Measurements ◽  
Hardness Testing ◽  
X Ray Diffraction ◽  
X Ray

Theoretical calculation and experimental investigation of the isothermal section of a ternary Bi-Cu-Ga system at 100 oC are presented in this paper. Thermodynamic binary-based calculation of the isothermal section was performed using Pandat software. Experimental investigation included microstructural analysis carried out using light optical microscopy (LOM) and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), phase composition analysis using X-ray diffraction (XRD), Brinell and Vickers hardness testing and electrical conductivity measurements. In total, thirty alloy samples with compositions along three vertical sections Bi-CuGa, Cu-BiGa and Ga-BiCu were studied. The obtained experimental results support the calculated phase regions of the isothermal section at 100 oC. Hardness of individual phases as well as hardness and electrical conductivity of the studied alloys were measured. Based on the experimentally obtained results iso-lines of Brinell hardness and electrical conductivity along the whole compositional range were calculated by using appropriate mathematical models.

Experimental Investigation of Aluminium Hybrid Composites Reinforced with ZnS, TiO2 and BaTiO3 Produced Through Powder Metallurgy

2021 ◽  
Vol 13 (3) ◽  
Author(s):  
S. Rajeshkannan ◽  
I. Manikandan ◽  
M. Vigneshkumar
Keyword(s):  
Powder Metallurgy ◽  
Hybrid Composites ◽  
Brinell Hardness ◽  
High Hardness ◽  
High Strength ◽  
Hardness Test ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
Testing Instrument ◽  
X Ray

Semiconductors like ZnS, TiO2 and BaTiO3 were reinforced with Al-Al2O3 Metal Matrix Composites (MMCs) and were made through powder metallurgy in order to have high strength, high hardness and good thermal conductivity compared with conventional materials. Three MMC of test specimens were prepared with varying reinforcement ratio Al-Al2O3-ZnS(94-5-1), Al-Al2O3-TiO2(94-5-1), Al-Al2O3-BaTiO3(94-5-1) percentage by weight respectively. The hardness test has been made by using Brinell hardness testing instrument. Hardness test revealed that the addition of reinforcement TiO2, BaTiO3 increases the hardness value. However, the addition of ZnS to the Al-Al2O3 MMCs showed decrease in the hardness value. The crystal structure of the 3 composites were examined through X-Ray Diffraction (XRD) peaks.

Microstructure Evolution and Properties of 7A56 Aluminum Alloy by Homogenization

2017 ◽  
Vol 898 ◽  
pp. 153-158 ◽  
Author(s):  
Da Xu ◽  
Zhi Hui Li ◽  
Guo Jun Wang ◽  
Long Bing Jin ◽  
Hong Wei Yan ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Microstructure Evolution ◽  
Equilibrium Phase ◽  
Hardness Test ◽  
Homogenization Temperature ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Second Phases ◽  
Al Matrix

The microstructure evolution and properties of Al-matrix in homogenized 7A56 alloy were investigated by scanning electron microscope (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), electrical conductivity and hardness test. The second phases in as-cast 7A56 alloy consisted of AlZnMgCu, Al2Cu and Al7Cu2Fe. With the homogenization temperature increasing, more non-equilibrium phase AlZnMgCu was dissolved into Al-matrix. The diffusion of alloying elements from AlZnMgCu phase into Al-matrix leads to a decrease of electrical conductivity and an increase of hardness. The lattice constant of α-Al has an increases of 0.0019 Å, 0.0032 Å and 0.0053 Å after 380°C/24h,430°C/24h,and 470°C/24 h treatment,respectively.

scholarly journals The influence of chemical composition on microstructure, hardness and electrical conductivity of Ag-Bi-In alloys at 100 °C

10.30544/265 ◽  
2017 ◽  
Vol 23 (1) ◽  
pp. 65-82
Author(s):  
Vladan Ćosović ◽  
Duško Minić ◽  
Milena Premović ◽  
Dragan Manasijević ◽  
Aleksandar Đorđević ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Isothermal Section ◽  
Energy Dispersive Spectrometry ◽  
Xrd Analysis ◽  
Ternary Alloys ◽  
Mechanical And Electrical Properties ◽  
Calculated Liquidus ◽  
Phase Transition Temperatures ◽  
Corrected Data ◽  
Invariant Equilibria

Considering possible applications and scarceness of literature data, Ag-Bi-In system was investigated in terms of microstructure, mechanical and electrical properties of ternary alloys from an isothermal section at 100oC. Based on the experimentally obtained results hardness and electrical conductivity of all ternary alloys from the ternary Ag-Bi-In system at 100oC were predicted. In addition, the selected isothermal section was further thermodynamically assessed and experimentally studied using scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS), X-ray powder diffraction (XRD) analysis and light optical microscopy (LOM). Phase transition temperatures of alloys with overall compositions along vertical sections x(Ag)=0.5 as well as liquidus temperatures were experimentally determined by DTA. The experimentally obtained results were compared with literature data and with the results of thermodynamic calculation of phase equilibria based on CALPHAD method and corrected data for Ag-In binary system. Calculated liquidus projection, invariant equilibria and phase diagram of the Ag-Bi-In ternary system are presented as well.

scholarly journals Design of magnetron co-sputtering configuration for preparing magnesium tin silicide-based thermoelectric alloy thin films

2020 ◽  
Vol 22 (4) ◽  
pp. 385-390
Author(s):  
Anh Tuan Thanh Pham ◽  
Cuong Nhat Le ◽  
Dung Van Hoang ◽  
Truong Huu Nguyen ◽  
Phuong Thanh Ngoc Vo ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Elemental Composition ◽  
Power Factor ◽  
Xrd Analysis ◽  
Structure Characteristic ◽  
Good Adherence ◽  
X Ray ◽  
The Individual

Introduction: Magnesium tin silicide (MgSiSn) is known as a good-thermoelectric-performance, safe and cost-efficient alloy material. The goal of this work is to design a magnetron co-sputtering configuration for depositing alloy thin films from three independent metal targets including magnesium (Mg), silicon (Si) and tin (Sn). Methods: By this solution, the elemental composition of the MgSiSn thin films can be effectively controlled through changing sputtering power of the individual magnetron. The actual values of elemental composition in the as-deposited films were verified by using energy-dispersive X-ray spectroscopy. The as-deposited thin films were investigated carefully by using the X-ray diffraction to recognize crystalline structure characteristics. Most importantly, typically thermoelectric parameters including Seebeck coefficient, electrical conductivity and power factor were indicated as functions of temperature. Results: The XRD analysis exhibits cubic anti-fluorite-type structure characteristic of the MgSiSn films; however, the presence of segregated Mg phase is still observed. The testing results for the representative MgSiSn thin film with good adherence show the power factor of PF ~15×10-3 W/mK2, as a result of Seebeck coefficient of S ~132 µV/K and electrical conductivity of σ ~9000 S/cm, at 373 K. At higher temperature than 473 K, the semiconducting behavior of the films tends to transform from p-type to n-type. Conclusion: The three-target co-sputtering configuration shows the possibility of successfully preparing alloy MgSiSn thin films with good adherence on Si substrate. Furthermore, the testing result suggests that the as-deposited MgSiSn thin films have some potential thermoelectric characteristics, which can be improved more significantly.  

Characterization of Al and Al-Cr-Al Thin Films

1986 ◽  
Vol 77 ◽  
Author(s):  
O. F. De Lima ◽  
Y. Lepetre ◽  
M. B. Brodsky
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Electrical Resistivity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Resistivity Measurements ◽  
The Individual ◽  
Perfect Continuity ◽  
Substrate Temperatures

ABSTRACTTEM, X-ray diffraction, and electrical resistivity measurements were used to study the microstructure and the growth of AI-Cr-AI film sandwiches, where the individual Al layers were 300 Å thick and the Cr thickness was varied between 0–10 atomic layers. The base vacuum was around 1.0 × 10−10 torr, substrate temperatures varied between 100–350 °C, and evaporation rates were 3Å/s for Al and ∼0.1 – 0.2 Å/s for Cr. All Al films had a strong (111) texture and showed a non-percolative island structure at 350 °C. The films became connected at lower substrate temperatures, reaching perfect continuity at 100°C. However, electrical conductivity is achieved also for the films deposited at 350 °C when one or more atomic layers of Cr are sandwiched between the Al layers. Results for the superconducting critical temperature and resistivity are discussed in terms of Cr diffusion into Al and the film size effect.

scholarly journals Effect of chemical composition on the microstructure, hardness and electrical conductivity profiles of the Bi-Ge-In alloys

10.30544/561 ◽  
2020 ◽  
Vol 26 (4) ◽  
pp. 413-429
Author(s):  
Milena Premovic ◽  
Aleksandar Djordjevic ◽  
Dusko Minic ◽  
Milan Kolarevic ◽  
Milica Tomovic
Keyword(s):  
Mathematical Model ◽  
Electrical Conductivity ◽  
Composition Range ◽  
Brinell Hardness ◽  
Composition Analysis ◽  
Anova Analysis ◽  
Isothermal Sections ◽  
X Ray ◽  
Energy Dispersion Spectrometry ◽  
Phase Balance

In this study, the microstructure, hardness, and electrical properties of selected ternary Bi-Ge-In alloys were investigated. Isothermal sections of the Bi-Ge-In system at 25, 200, and 300 ° C were extrapolated using optimized thermodynamic parameters from the literature. The used experimental techniques include optical microscopy, X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and energy dispersion spectrometry (EDS), Brinell hardness, and electrical conductivity measurements. The results of EDS phase composition analysis were compared with the calculated isothermal sections and a good overall agreement was reached. The results of the XRD were also in line with the predicted phase balance. By using ANOVA analysis and experimental results of Brinell hardness and electrical conductivity, a mathematical model was suggested for the calculation of these properties along with all composition ranges. The appropriated mathematical model was subsequently used for the prediction of hardness and electrical conductivity throughout the whole composition range.

TiN-Al Composite Coatings on A356 Alloy by Mechanical Alloying

2017 ◽  
Vol 898 ◽  
pp. 1359-1368 ◽  
Author(s):  
Zhen Gui Yuan ◽  
Lu Yao Pan ◽  
Shan Jiang ◽  
Li Hong Wang ◽  
Min Zuo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Alloying ◽  
Brinell Hardness ◽  
Composite Coatings ◽  
A356 Alloy ◽  
Weight Ratio ◽  
Hardness Test ◽  
X Ray ◽  
Al Composite ◽  
Milling Duration

The TiN-Al composite coatings on A356 alloy were successfully synthesized by mechanical alloying (MA) of Al, TiN and C powders under argon atmosphere. Meanwhile, the optimal parameters for mechanical milling processing were determined by changing the material ratio (Al: TiN: C), milling time and the ball-to-powder weight ratio, which might have a significant improvement on the wear resistance of A356 alloys. The microstructures and mechanical properties of A356 alloy samples with TiN-Al composite coatings were characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM) equipped with energy dispersive X-ray spectroscopy (EDS) and Brinell hardness test. It was found that under the optimal conditions, i.e. the material ratio of (Al: TiN: C= 17.5:1.5:1), the ball-to-powder weight ratio of 14:1 and the milling duration of 12 h, the Brinell hardness of sample-6 could be remarkably increased to 143.80 HBW. With the TiN-Al coatings fabricated by MA process, the mechanical properties of aluminum alloys could be significantly improved.

scholarly journals Mechanical and electrical properties of the Bi-Ge-Sn alloys

10.30544/562 ◽  
2020 ◽  
Vol 26 (4) ◽  
pp. 395-412
Author(s):  
Milena Premovic ◽  
Aleksandar Djordjevic ◽  
Dusko Minic ◽  
Milica Tomovic ◽  
Branko Radicevic ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Electrical Conductivity ◽  
Isothermal Section ◽  
Electrical Properties ◽  
Binary Systems ◽  
Brinell Hardness ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Mechanical And Electrical Properties ◽  
Good Agreement

Mechanical and electrical properties of the ternary Bi-Ge-Sn alloys were investigated in this study. Calculation of isothermal section at 200, 300, and 25 ºC was carried out by using optimized thermodynamic parameters for the constitutive binary systems. Microstructures of alloys were observed by using optical microscopy and scanning electron microscopy (SEM). Phases in microstructures have been detected by X-ray diffraction (XRD) analysis and compositions of the phase by energy dispersive spectrometry (EDS). EDS results were compared with the predicted isothermal section at 200 and 300 ºC, and good agreement has been reached between them. The Brinell hardness and electrical conductivity of selected alloys were measured.  Through ANOVA analysis and application of the obtained results, an appropriate mathematical model is proposed for every composition of alloys. By using the appropriated mathematical model for Brinell hardness and electrical conductivity, isolines for those properties were presented.

Removing Substrate Background in TEM Microanalysis

1974 ◽  
Vol 32 ◽  
pp. 568-569
Author(s):  
John C. Russ ◽  
Nicholas C. Barbi
Keyword(s):  
Electrical Conductivity ◽  
Rapid Growth ◽  
Organic Film ◽  
Absolute Concentration ◽  
Background Signal ◽  
X Ray ◽  
Elemental Concentrations ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
The Continuum

The rapid growth of interest in attaching energy-dispersive x-ray analysis systems to transmission electron microscopes has centered largely on microanalysis of biological specimens. These are frequently either embedded in plastic or supported by an organic film, which is of great importance as regards stability under the beam since it provides thermal and electrical conductivity from the specimen to the grid.Unfortunately, the supporting medium also produces continuum x-radiation or Bremsstrahlung, which is added to the x-ray spectrum from the sample. It is not difficult to separate the characteristic peaks from the elements in the specimen from the total continuum background, but sometimes it is also necessary to separate the continuum due to the sample from that due to the support. For instance, it is possible to compute relative elemental concentrations in the sample, without standards, based on the relative net characteristic elemental intensities without regard to background; but to calculate absolute concentration, it is necessary to use the background signal itself as a measure of the total excited specimen mass.

Sign in / Sign up

Export Citation Format

Share Document