Mechanical Alloying Influence on the Sintering of Cu-Fe Compound Powders

2007 ◽  
Vol 353-358 ◽  
pp. 1350-1353 ◽  
Author(s):  
Jin Feng Sun ◽  
Ming Zhi Wang ◽  
Xiao Pu Li ◽  
Zhan Wen He ◽  
Yu Cheng Zhao
Keyword(s):  
Activation Energy ◽  
Mechanical Alloying ◽  
Sintering Temperature ◽  
Sintering Process ◽  
Stored Energy ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Structure Strength ◽  
Activation Energy Of Diffusion

In this paper, X-ray diffraction (XRD), differential scanning calorimetry (DSC) and sintering process were used to characterize Cu-Fe compound powders milled for different times. The increment of defects and the change of granularity, grain size and crystal structure were discussed. Mechanical Alloying (MA) influence on the sintering of Cu-Fe compound powders was analyzed. The results showed that, the refinement of the powders and the increment of defects such as interface and dislocation induced the energy storage. The stored energy released in the sintering process, which reduced the activation energy of vacancy and the activation energy of diffusion. So the sintering temperature was reduced and the structure, strength and hardness of specimens were improved.

scholarly journals Development of a dielectric ceramic based on diatomite-titania. Part one: powder preparation and sintering study

Cerâmica ◽  
1997 ◽  
Vol 43 (283-284) ◽  
pp. 167-170
Author(s):  
Elcio Correia de Souza Tavares ◽  
Jamilson Pinto Medeiros ◽  
Uílame Umbelino Gomes ◽  
Wilson Acchar
Keyword(s):  
Activation Energy ◽  
Sintering Temperature ◽  
Linear Shrinkage ◽  
Sintering Process ◽  
Flow Mechanism ◽  
X Ray Diffraction ◽  
Mass Variation ◽  
Powder Preparation ◽  
Dielectric Ceramic ◽  
X Ray

This work presents powder preparation and sintering experiments of a mixture diatomite-titania. X-ray diffraction, DTA, TGA as well as chemical and microstructural analyses were made. The sintering process was investigated as a function of sintering temperature and time, mass variation, linear shrinkage and activation energy. The results show that sintering of diatomite-titania could be described by a viscous flow mechanism.

Synthesis Mechanism and Microstructure Characterization of BaIn2O4

2011 ◽  
Vol 347-353 ◽  
pp. 1342-1347 ◽  
Author(s):  
Ping Ren ◽  
Li Cheng Zhou ◽  
Jun Xi Zhang ◽  
Hong Yun
Keyword(s):  
Sintering Temperature ◽  
Precipitation Method ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Synthesis Mechanism ◽  
X Ray ◽  
Grain Sizes ◽  
Co Precipitation

The synthesis mechanism and microstructures of BaIn2O4 particles were analyzed by simultaneous thermogravimetry - differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), and scanning electron microscope (SEM). Firstly, In(OH)3 and BaCO3 precursors were prepared by the co-precipitation method. Next, during the sintering process In(OH)3 initially decomposed into In2O3 and water, and then BaCO3 reacted with In2O3 to synthesize Ba4In6O13. Finally, Ba4In6O13 and In2O3 further reacted to form BaIn2O4. The obtained BaIn2O4 particles were in monoclinic structure and exhibited high crystal quality. The grains were tightly bound together and their boundaries became blurry. The grain sizes increased with increasing the sintering temperature.

scholarly journals Effects of Sintering Temperature on Densification, Microstructure and Mechanical Properties of Al-Based Alloy by High-Velocity Compaction

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 218
Author(s):  
Xianjie Yuan ◽  
Xuanhui Qu ◽  
Haiqing Yin ◽  
Zaiqiang Feng ◽  
Mingqi Tang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Velocity ◽  
Sintered Density ◽  
Sintering Temperature ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
High Velocity Compaction ◽  
Sintered Temperature

This present work investigates the effects of sintering temperature on densification, mechanical properties and microstructure of Al-based alloy pressed by high-velocity compaction. The green samples were heated under the flow of high pure (99.99 wt%) N2. The heating rate was 4 °C/min before 315 °C. For reducing the residual stress, the samples were isothermally held for one h. Then, the specimens were respectively heated at the rate of 10 °C/min to the temperature between 540 °C and 700 °C, held for one h, and then furnace-cooled to the room temperature. Results indicate that when the sintered temperature was 640 °C, both the sintered density and mechanical properties was optimum. Differential Scanning Calorimetry, X-ray diffraction of sintered samples, Scanning Electron Microscopy, Energy Dispersive Spectroscopy, and Transmission Electron Microscope were used to analyse the microstructure and phases.

scholarly journals Formation of metal oxide-based hydroxysodalite by alkali-activation of kaolinite

Chemija ◽  
2020 ◽  
Vol 31 (3) ◽  
Author(s):  
Ehab AlShamaileh ◽  
Muayad Esaifan ◽  
Qusay Abu-Afifeh
Keyword(s):  
Activation Energy ◽  
Metal Oxide ◽  
Alkali Activation ◽  
Dsc Analysis ◽  
X Ray Diffraction ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Xrd Study ◽  
Dsc Curves

The formation of metal oxide-based hydroxysodalite by alkali-activation of kaolinite is studied using X-ray diffraction (XRD) study and differential scanning calorimetry (DSC) analysis. Different metal oxides (CoO, MgO, FeO and SiO2) were used to form the metal oxide-based hydroxysodalite. The transformation from kaolinite into hydroxysodalite is confirmed by XRD. In the thermodynamic study, the maximum peak temperatures for DSC curves at various heating rates were used to determine the activation energy (Ea) of the hydroxysodalite formation. With magnesium oxide and cobalt oxide, the formation process was found to be exothermic while it was endothermic with iron oxide.

Effect of Process on the Dielectric Properties of BaTiO3-Based X9R Ceramics

2014 ◽  
Vol 906 ◽  
pp. 18-24 ◽  
Author(s):  
Bao Lin Zhang ◽  
Bin Bin Zhang ◽  
Ning Ning Wang ◽  
Jing Ming Fei
Keyword(s):  
Particle Size ◽  
Dielectric Properties ◽  
Milling Time ◽  
Sintering Temperature ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Sintered Ceramic ◽  
X Ray ◽  
Particle Size Analyzer

The effect of milling time and sintering process on the dielectric properties of BaTiO3-based X9R ceramics was investigated. The characterization of the raw powders and the sintered ceramic was carried out by X-ray diffraction and scanning electron microscopy. The particle size distribution of the mixed powders was examined by Laser Particle Size Analyzer. The results shown that with the milling time extended, the Cruie Peak was depressed, or even disappeared. Moreover, with the rise of sintering temperature, the dielectric constant of the ceramics increased and the dielectric loss decreased gradually. Eventually, by milling for 11h and sintering at 1090°Cfor 2h, good dielectric properties were obtained, which were ε25°C≥ 2526, εr/εr25°C≤± 12% (–55~200°C), tanδ≤1.12% (25°C).

Study on the Preparation Technique and Magnetostriction of Sinter Tb0.7Pr0.3Fe1.80 Alloy

2012 ◽  
Vol 189 ◽  
pp. 152-156
Author(s):  
H.Y. Yin ◽  
X. Liu ◽  
R. Wang ◽  
Jin Jun Liu ◽  
R.R. Lin ◽  
...  
Keyword(s):  
Mechanical Alloying ◽  
Laves Phase ◽  
Type Structure ◽  
Preparation Technique ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Standard Strain ◽  
X Ray ◽  
Magnetoelastic Properties ◽  
Composite Samples

Mechanical alloying (MA) and subsequent solid sintering process was used to prepare the Pr-containing pseudobinary Tb0.7Pr0.3Fe1.80alloys. The structural and magnetoelastic properties were in comparative investigated by means of x-ray diffraction and a standard strain technique for sinter and composite samples. The high Pr-content (Tb,Pr)Fe2Laves phase with MgCu2-type structure for the composition Tb0.7Pr0.3Fe1.80 were synthesized by MA plus annealing at 500 °C.

Thermodynamic Characterization on Hydrogen Absorption and Desorption Reactions of Lithium – Silicon Alloy

2010 ◽  
Vol 654-656 ◽  
pp. 2815-2818 ◽  
Author(s):  
Koichi Doi ◽  
Satoshi Hino ◽  
Hiroki Miyaoka ◽  
Takayuki Ichikawa ◽  
Yoshitsugu Kojima
Keyword(s):  
Mechanical Alloying ◽  
Enthalpy Change ◽  
Diffraction Measurement ◽  
Hydrogen Storage Materials ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Pressure Differential Scanning Calorimetry ◽  
Desorption Reaction ◽  
Hoff Plot

Lithium hydride LiH is one of the attractive hydrogen storage materials, because it stores 12.7 mass% of H2. However, H2 desorption reaction occurs over 600 °C due to the large enthalpy change of H2 desorption Ho = 181 kJ/mol H2. The purpose of this work is to control the enthalpy change of LiH to much lower value by a mechanical alloying with Si, where the Li-Si alloy is thermodynamically more stable than Li. The alloy was synthesized from Li granule and Si powder by a mechanical alloying method. The H2 absorption and desorption properties were characterized by High-Pressure Differential Scanning Calorimetry and Thermogravimetry - Differential Thermal Analysis - Mass Spectroscopy, and X-ray diffraction measurement. Pressure - Composition - Isotherm measurements were performed at 400, 450, and 500 °C to estimate the enthalpy change. From the results, it was confirmed that reversible H2 ab/desorption reactions of the Li-Si alloy were expressed as 7LiH + 3Si ↔ (3/7)Li12Si7 + (13/7)LiH + (18/7)H2 ↔ Li7Si3 + (7/2)H2 (theoretically 5.0 mass% H2) at 400 °C. From van’t Hoff plot obtained by the results of PCI measurements, the enthalpy change of the former reaction was estimated to be Ho = 103 kJ/mol H2, which is lower than that of LiH.

scholarly journals Fabrication of Porous Hydroxyapatite Granules as an Effective Adsorbent for the Removal of Aqueous Pb(II) Ions

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Duyen Thi Le ◽  
Thao Phuong Thi Le ◽  
Hai Thi Do ◽  
Hanh Thi Vo ◽  
Nam Thi Pham ◽  
...  
Keyword(s):  
Industrial Wastewater ◽  
Sintering Temperature ◽  
Order Kinetic ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Porous Hydroxyapatite ◽  
X Ray ◽  
Langmuir Adsorption ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Porous hydroxyapatite (HAp) granules have been successfully fabricated from a HAp powder precursor and polyvinyl alcohol (PVA) additive by a simple sintering process. The composition and microstructures of the HAp were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) equipped with an energy dispersive X-ray (EDX) spectrometer. The effects of sintering temperature and PVA/HAp mass ratios on color, water stability, morphology, and chemical composition of HAp are discussed. Optimum conditions for the fabrication of HAp granules were found to be a PVA/HAp mass ratio of 3/20 and a sintering temperature of 600°C for 4 h. Accordingly, the obtained HAp is white in color, is in the granular form with a size of about 2 × 10 mm, and has a specific surface area of 70.6 m2/g. The adsorption of Pb2+ onto the as-prepared HAp granules was carried out in aqueous solution by varying the pH, the adsorbent dose, the initial concentration of Pb2+, and the contact time. The results of adsorption stoichiometry of Pb2+ on the HAp granule adsorbent were fitted to the Langmuir adsorption isotherm model (R2 = 0.99). The adsorption capacity and removal efficiency of the HAp granule adsorbent for Pb2+ under optimal conditions were found to be 7.99 mg/g and 95.92%, respectively. The adsorption process obeyed a pseudo-second-order kinetic model with R2∼1. The porous HAp granules studied in this work showed potential for the removal of Pb2+ from industrial wastewater.

Fabrication of Mg2Si Thermoelectric Materials by Mechanical Alloying and Spark-Plasma Sintering Process

2006 ◽  
Vol 6 (11) ◽  
pp. 3429-3432
Author(s):  
Chung-Hyo Lee ◽  
Seong-Hee Lee ◽  
Sung-Yong Chun ◽  
Sang-Jin Lee
Keyword(s):  
Grain Size ◽  
Mechanical Alloying ◽  
Spark Plasma Sintering ◽  
Room Temperature ◽  
Atomic Ratio ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plasma Sintering ◽  
Spark Plasma

A mixture of pure Mg and Si powders with an atomic ratio 2:1 has been subjected to mechanical alloying (MA) at room temperature to prepare the Mg2Si thermoelectric material. Mg2Si intermetallic compound with a grain size of 50 nm can be obtained by MA of Mg66.7Si33.3 powders for 60 hours and subsequently annealed at 620 °C. Consolidation of the MA powders was performed in a spark plasma sintering (SPS) machine using graphite dies up to 800–900 °C under 50 MPa. The shrinkage of consolidated samples during SPS was significant at about 250 °C and 620 °C. X-ray diffraction data shows that the SPS compact from 60 h MA powders consolidated up to 800 °C consists of only nanocrystalline Mg2Si compound with a grain size of 100 nm.

Equal channel angular pressing processing routes and associated structure modification: a differential scanning calorimetry and X-ray line profile analysis

2012 ◽  
Vol 27 (3) ◽  
pp. 194-199 ◽  
Author(s):  
A. Sarkar ◽  
Satyam Suwas ◽  
D. Goran ◽  
J.-J. Fundenberger ◽  
L.S. Toth ◽  
...  
Keyword(s):  
Activation Energy ◽  
Differential Scanning Calorimetry ◽  
Equal Channel Angular Pressing ◽  
Line Profile ◽  
Profile Analysis ◽  
Line Profile Analysis ◽  
Stored Energy ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Angular Pressing

The effectiveness of different routes of equal channel angular pressing (A, Bc, and C) is studied for commercially pure copper. The stored energy and the activation energy of recrystallization for the deformed samples were quantified using differential scanning calorimetry and X-ray diffraction line profile analysis. Results of the study revealed that the dislocation density and the stored energy are higher in the case of route Bc deformed sample. The activation energy for recrystallization is lower for route Bc.

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