scholarly journals SYNTHESIS OF Cu1.6Bi4.6S8 COMPOUND FOR THERMOELECTRIC APPLICATION

2019 ◽  
Vol 25 (2) ◽  
pp. 86
Author(s):  
Binh Ngoc Duong ◽  
Long Duc Bui
Keyword(s):  
Heat Treatment ◽  
Heating Rate ◽  
Ball Mill ◽  
Milled Powder ◽  
Xrd Analysis ◽  
High Energy ◽  
Starting Mixture ◽  
Heat Treated ◽  
Annealed Powder ◽  
Thermoelectric Application

<p class="AMSmaintext">In this work, Cu<sub>1.6</sub>Bi<sub>4.6</sub>S<sub>8</sub> thermoelectric compound was synthesized using high energy milling and heat treatment. The starting mixture include Cu, Bi and S elemental powders at the stoichiometry ratio of the formula Cu<sub>1.6</sub>Bi<sub>4.6</sub>S<sub>8</sub> were ball milled in a planetary ball mill and heat treated in an electric furnace. The results shown that after 10 hours of milling, a compound identified as Cu<sub>3.21</sub>Bi<sub>4.79</sub>S<sub>9</sub> was formed. The 16h milled powder was heat-treated at 350, 400 and 450ºC for 1 hours at a heating rate of 8 ºC/minute, XRD of the annealed powder reveals that the Cu<sub>3.21</sub>Bi<sub>4.79</sub>S<sub>9</sub> obtained fully transformed into Cu<sub>1.6</sub>Bi<sub>4.6</sub>S<sub>8</sub> after being heat treated at 400ºC. Meanwhile, Bi<sub>2</sub>S<sub>3</sub> was found in the powder being annealed at 350ºC. The 5h milled powder was also annealed at 400ºC for 1 hours at a heating rate of 2 and 8 ºC/minute, XRD analysis show that Cu<sub>1.6</sub>Bi<sub>4.6</sub>S<sub>8</sub> was also formed in the heat-treated powder with the heating rate of 2 ºC/min.</p>

EFFECT OF MILLING TIME ON MECHANOCHEMICAL SYNTHESIS OF TiO2 NANOPARTICLES

2008 ◽  
Vol 22 (18n19) ◽  
pp. 2955-2961 ◽  
Author(s):  
MARYAM SALARI ◽  
MASIH REZAEE ◽  
S. M. MOUSAVI KOIE ◽  
P. MARASHI ◽  
H. ABOUTALEBI
Keyword(s):  
Milling Time ◽  
Titanium Dioxide Nanoparticles ◽  
Milled Powder ◽  
High Energy ◽  
Spherical Particles ◽  
X Ray Diffraction ◽  
Starting Mixture ◽  
Annealed Powder ◽  
Energy Ball ◽  
Titanyl Sulphate

Titanium dioxide nanoparticles have great potential for use in photocatalytic applications, cosmetics, white pigments and so on. In this paper, the effect of milling time on particle size, morphology and phase composition of TiO 2 nanoparticles, prepared by mechanochemical method, was investigated by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). TiO 2 nanoparticles were prepared by the use of high energy ball milling of titanyl sulphate ( TiOSO 4) and NaCl powders as the starting mixture in different milling durations. The milled powder was annealed at 700°C for 30 min. The NaCl powder, used as the diluent phase, was removed by washing the annealed powder with distilled water. It was found that with increasing milling time, decrease in the size of equiaxed spherical particles and increase in temperature of anatase to rutile transformation ( A → R ) can be observed.

Mechanical Behaviour of Gas Nitrided Ti6Al4V Bars Produced by Selective Laser Melting

2016 ◽  
Vol 704 ◽  
pp. 225-234 ◽  
Author(s):  
Peter Franz ◽  
Aamir Mukhtar ◽  
Warwick Downing ◽  
Graeme Smith ◽  
Ben Jackson
Keyword(s):  
Heat Treatment ◽  
Selective Laser Melting ◽  
Nitrided Layer ◽  
Xrd Analysis ◽  
Compound Layer ◽  
Processing Parameters ◽  
Heat Treatments ◽  
Laser Melting ◽  
Gas Nitriding ◽  
Heat Treated

Gas atomized Ti-6Al-4V (Ti64) alloy powder was used to prepare distinct designed geometries with different properties by selective laser melting (SLM). Several heat treatments were investigated to find suitable processing parameters to strengthen (specially to harden) these parts for different applications. The results showed significant differences between tabulated results for heat treated billet Ti64 and SLM produced Ti64 parts, while certain mechanical properties of SLM Ti64 parts could be improved by different heat treatments using different processing parameters. Most heat treatments performed followed the trends of a reduction in tensile strength while improving ductility compared with untreated SLM Ti64 parts.Gas nitriding [GN] (diffusion-based thermo-chemical treatment) has been combined with a selected heat treatment for interstitial hardening. Heat treatment was performed below β-transus temperature using minimum flow of nitrogen gas with a controlled low pressure. The surface of the SLM produced Ti64 parts after gas nitriding showed TiN and Ti2N phases (“compound layer”, XRD analysis) and α (N) – Ti diffusion zones as well as high values of micro-hardness as compared to untreated SLM produced Ti64 parts. The microhardness profiles on cross section of the gas nitrided SLM produced samples gave information about the i) microhardness behaviour of the material, and ii) thickness of the nitrided layer, which was investigated using energy dispersive spectroscopy (EDS) and x-ray elemental analysis. Tensile properties of the gas nitrided Ti64 bars produced by SLM under different conditions were also reported.

scholarly journals Analysis of Different 100Cr6 Material States Using Particle-Oriented Peening

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1056 ◽  
Author(s):  
Anastasiya Toenjes ◽  
Nicole Wielki ◽  
Daniel Meyer ◽  
Axel von Hehl
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Plastic Deformation ◽  
Heating Rate ◽  
Differential Scanning Calorimeter ◽  
Microstructural Properties ◽  
Material Development ◽  
Heat Treated ◽  
Aisi 52100 ◽  
Novel Method

As part of a novel method for evolutionary material development, particle-oriented peening is used in this work to characterize 100Cr6 (AISI 52100) microparticles that were heat-treated by means of a differential scanning calorimeter (DSC). The plastic deformation of the samples in particle-oriented peening is correlated with the microstructural properties considering different heat-treatment variations. While the heating rate was kept constant (10 K/min) for all heat treatments, different heating temperatures (500 °C, 800 °C, 1000 °C and 1100 °C) were realized, held for 20 min and then cooled down at a rate of 50 K/min. Thereby, microstructural states with different (mechanical) properties are generated. For validation, microsections of the particles were analyzed and additional universal microhardness measurements (UMH) were performed. It could be shown that the quickly assessable plastic deformation descriptor reacts sensitively to the changes in the hardness due to the heat treatment.

High Purity Ti2AlC Powder Prepared by a Novel Method

2010 ◽  
Vol 658 ◽  
pp. 340-343 ◽  
Author(s):  
Jian Feng Zhu ◽  
Guo Quan Qi ◽  
Fen Wang ◽  
Hai Bo Yang
Keyword(s):  
Heat Treatment ◽  
Thermal Treatment ◽  
High Purity ◽  
High Energy ◽  
High Energy Milling ◽  
Heat Treated ◽  
Novel Method ◽  
Increasing Temperature ◽  
Milled Powders

Ti2AlC powders with high purity were successfully synthesized via high energy milling and heat treatment of Ti, C and Al powders. The effects of composition and thermal treatment on the formation and purity of Ti2AlC were examined in detail. The results shown a mechanically induced self-propagating reaction (MSR) was triggered to form Ti3AlC2, TiC and TiAlx during the high energy milling. When the as-milled powders were heat treated, Ti2AlC was initially formed by the reaction between TiAl and TiC. With continuously increasing temperature, Ti2AlC was also produced by the reaction between TiAl and Ti3AlC2.

scholarly journals Влияние термообработки на электрические характеристики полуизолирующих слоев, полученных с помощью облучения n-SiC высокоэнергетическими ионами аргона

2018 ◽  
Vol 44 (6) ◽  
pp. 11 ◽  
Author(s):  
П.А. Иванов ◽  
А.С. Потапов ◽  
М.Ф. Кудояров ◽  
М.А. Козловский ◽  
Т.П. Самсонова
Keyword(s):  
Heat Treatment ◽  
Silicon Carbide ◽  
Room Temperature ◽  
High Energy ◽  
Room Temperature Resistivity ◽  
Electrical Characteristics ◽  
Near Surface ◽  
Heat Treated ◽  
Argon Ions ◽  
Temperature Resistivity

AbstractIrradiation of crystalline n -type silicon carbide ( n -SiC) with high-energy (53-MeV) argon ions was used to create near-surface semi-insulating ( i -SiC) layers. The influence of subsequent heat treatment on the electrical characteristics of i -SiC layers has been studied. The most high-ohmic ion-irradiated i -SiC layers with room-temperature resistivity of no less than 1.6 × 10^13 Ω cm were obtained upon the heat treatment at 600°C, whereas the resistivity of such layers heat-treated at 230°C was about 5 × 10^7 Ω cm.

Effect of Deposition Time and Heat Treatment on Structural and Mechanical Properties of Ni3Al Coating Deposited by Air Plasma Spraying on Tool Steel

2021 ◽  
Vol 875 ◽  
pp. 259-265
Author(s):  
Sabah Zaman ◽  
Khalid Mehmood ◽  
Shabbar Abbas ◽  
Mudassir Rauf ◽  
Shaheed Khan
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Plasma Spraying ◽  
Tool Steel ◽  
Deposition Time ◽  
Treatment Time ◽  
Xrd Analysis ◽  
Air Plasma ◽  
Air Plasma Spraying ◽  
Heat Treated

This study focuses on the effect of deposition time and heat treatment on Ni3Al coatings with respect to mechanical and microstructural properties of the material. Air plasma spraying technique was employed to deposit Ni3Al on hot work tool steel samples for different deposition times i.e. 15-45 seconds. The coated samples were then heat treated at 900 °C for 20 to 100 hours at an interval of 20 hours each. The characterization tools such as X-Ray diffraction (XRD), optical and scanning electron microscopy (SEM) were used to study the homogeneity, phases formed and structure of coatings. All the coatings showed lamellar structure with distinctive boundaries along with the presence of some porosity and oxide particles. The XRD analysis of as prepared samples showed characteristic peaks of Ni3Al whereas of heat treated samples revealed NiO formation that increased with increasing heat treatment time. Micro-hardness and wear resistance measurements of the coated layer showed that they were increasing with the deposition time due to formation of more thick and dense layers. Formation of NiO, due to heat treatment imparted greater hardness and wear resistance to the coating. Moreover, the SEM study of heat-treated samples showed presences of alumina and spinel phases which were confirmed by energy dispersive spectroscopic analysis.

Effect of Heating Rate on the Microstructure and Mechanical Properties of Spark Plasma Sintered CNTs Reinforced Nickel Aluminide

2019 ◽  
Vol 821 ◽  
pp. 440-444
Author(s):  
Olusoji Oluremi Ayodele ◽  
Mary Ajimegoh Awotunde ◽  
Mxolisi Brendon Shongwe ◽  
Adewale Oladapo Adegbenjo ◽  
Bukola J. Babalola ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Heating Rate ◽  
Nickel Aluminide ◽  
Ball Mill ◽  
Time Pressure ◽  
High Energy ◽  
Powder Metallurgy Method ◽  
Multi Walled Carbon Nanotubes ◽  
Spark Plasma ◽  
Energy Ball

Powder metallurgy method was used to consolidate nickel aluminide reinforced multi-walled carbon nanotubes through planetary ball mill in order to facilitate the effective dispersion of carbon nanotubes (CNTs). In this investigation, 0.5 wt% of CNTs was added to the powder mixture of nickel and aluminum through two ball milling processes: low energy ball mill (LEBM) and high energy ball mill (HEBM). The bulk composites were synthesized by spark plasma sintering (SPS) at constant temperature, holding time, pressure of 32 MPa, 800 °C and 5 min respectively. The heating rate was varied between 50 and 150 °C/min. Microstructural evolutions of the composites were studied and densification of the composites was improved with increase in heating rate but depreciated as the heating rate was further increased. Vickers microhardness values of the fabricated composites were enhanced with increase in heating rate.

SYNTHESIS OF BARIUM HEXAFERRITE/IRON OXIDES MAGNETIC NANO-COMPOSITES VIA HIGH ENERGY BALL MILLING AND SUBSEQUENT HEAT TREATMENT

2012 ◽  
Vol 05 ◽  
pp. 519-526 ◽  
Author(s):  
M.J. MOLAEI ◽  
A. ATAIE ◽  
S. RAYGAN
Keyword(s):  
Heat Treatment ◽  
Milling Time ◽  
Barium Hexaferrite ◽  
High Energy ◽  
Magnetic Composite ◽  
Heat Treated ◽  
Milled Sample ◽  
High Density Recording ◽  
Milling Medium ◽  
Energy Ball

Barium hexaferrite ( BaFe 12 O 19) is a hard magnetic ceramic with superior magnetic properties and in powder form has potential for application in high density recording media. In this research a mechano-chemical approach was applied in order to achieve a nano-structured magnetic composite. Graphite was used to reduce barium hexaferrite in mechanical milling medium under argon atmosphere. Milling was carried out with a ball to powder mass ratio of 35 and rotation speed of 300 rpm. Effects of milling time on phase composition and morphology of the samples were evaluated by XRD and SEM techniques, respectively. XRD results revealed that after 20 hours of milling, nano-composite of BaFe 12 O 19/ Fe 3 O 4/ Fe 2 O 3 was obtained. By extending the milling time to 40 hours, FeO was detected as the dominant crystalline phase with crystallite size of 22 nm. Composite of Fe / FeO / Fe 3 O 4 was synthesized by controlled heat treatment of the 40 hours milled sample. SEM results revealed that particle size in the aforementioned heat treated composite sample reached to about 89 nm and the morphology of the samples changed slightly.

Heat Treated and As-Plated Electroless Duplex Ni-P/Ni-B Coatings: Evaluation of Hardness and Wear Resistance

2013 ◽  
Vol 853 ◽  
pp. 264-269 ◽  
Author(s):  
Gökce Dil ◽  
Ali Göksenli ◽  
Cagdas Calli ◽  
Faiz Muhaffel ◽  
Ali I. Aydeniz ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Electroless Nickel ◽  
Xrd Analysis ◽  
Maximum Value ◽  
Heat Treated ◽  
Pin On Disc ◽  
Substrate Steel ◽  
Duplex Coatings

The present work deals with the formation of NiP/NiB duplex coatings by electroless plating and evaluation of their hardness and wear resistance. The duplex coatings were prepared with Ni-P as the inner layer. To analyze the structure of the coatings, XRD analysis was carried out. According to the results, NiP and NiB coatings are amorphous in their as-plated condition and after applying heat-treatment at 450 °C for 1 h, both NiP and NiB coatings crystallize and produce nickel, nickel phosphide and nickel borides in the coatings. To determine the surface morphology and cross-section characteristics of the coatings, SEM observations were carried out and concluded that duplex coatings are uniform and good coherent exists between the duplex layers and the coatings are also connected closely to the substrate. The hardness of electroless nickel duplex coatings increased with applying heat treatment and reached maximum value at coatings annealed at 400 °C. To analyze the tribological properties, pin-on-disc tests were carried out. The wear track patterns on the coatings and on Al2O3balls were then examined by optical microscopy and EDS. The friction coefficient and wear rate of the coatings were lower than the substrate steel. Friction coefficient decreased from 0.43 to 0.36 and wear resistance decreased from 11.3 to 6.4 by applying heat treatment at 450 °C for 1 h to duplex coatings.

Influence of Cerium on the Deformation and Corrosion of Magnesium

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Sravya Tekumalla ◽  
Sankaranarayanan Seetharaman ◽  
Nguyen Quy Bau ◽  
Wai Leong Eugene Wong ◽  
Chwee Sim Goh ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Electron Microscope ◽  
Hot Extrusion ◽  
Microstructural Characterization ◽  
Xrd Analysis ◽  
Compressive Deformation ◽  
Heat Treated ◽  
Before And After ◽  
Elongation To Failure ◽  
Melt Deposition

In this study, a new magnesium (Mg) alloy containing 0.4% Ce was developed using the technique of disintegrated melt deposition followed by hot extrusion. The tensile and compressive properties of the developed Mg–0.4Ce alloy were investigated before and after heat treatment with an intention of understanding the influence of cerium on the deformation and corrosion of magnesium. Interestingly, cerium addition has enhanced the strength (by 182% and 118%) as well as the elongation to failure of Mg (by 93% and 8%) under both tensile and compressive loadings, respectively. After heat treatment, under compression, the Mg–0.4Ce(S) alloy exhibited extensive plastic deformation which was 80% higher than that of the as-extruded condition. Considering the tensile and compressive flow curves, the as-extruded Mg–0.4Ce and the heat treated Mg–0.4Ce(S) alloys exhibited variation in the nature and shape of the curves which indicates a disparity in the tensile and compressive deformation behavior. Hence, these tensile and compressive deformation mechanisms were studied in detail for both as-extruded as well as heat treated alloys with the aid of microstructural characterization techniques (scanning electron microscope (SEM), transmission electron microscope (TEM), selective area diffraction (SAD), and X-ray diffraction (XRD) analysis. Furthermore, results of immersion tests of both as-extruded and heat treated alloys revealed an improved corrosion resistance (by ∼3 times in terms of % weight loss) in heat treated state vis-a-vis the as-extruded state.

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