scholarly journals Master sintering curve: A practical approach to its construction

2010 ◽  
Vol 42 (1) ◽  
pp. 25-32 ◽  
Author(s):  
V. Pouchly ◽  
K. Maca
Keyword(s):  
Activation Energy ◽  
Practical Method ◽  
Practical Approach ◽  
Particle Sizes ◽  
Sintering Process ◽  
Cubic Zirconia

The concept of a Master Sintering Curve (MSC) is a strong tool for optimizing the sintering process. However, constructing the MSC from sintering data involves complicated and time-consuming calculations. A practical method for the construction of a MSC is presented in the paper. With the help of a few dilatometric sintering experiments the newly developed software calculates the MSC and finds the optimal activation energy of a given material. The software, which also enables sintering prediction, was verified by sintering tetragonal and cubic zirconia, and alumina of two different particle sizes.

scholarly journals Sintering densification curve: A practical approach for its construction from dilatometric shrinkage data

2008 ◽  
Vol 40 (2) ◽  
pp. 117-122 ◽  
Author(s):  
K. Maca ◽  
V. Pouchly ◽  
A.R. Boccaccini
Keyword(s):  
High Temperature ◽  
Sintering Temperature ◽  
Practical Method ◽  
Practical Approach ◽  
Powder Technology ◽  
Ceramic Processing ◽  
Sintering Process ◽  
Densification Curve ◽  
Sample Density ◽  
Sintering Shrinkage

This article summarizes the usage of high-temperature dilatometry in ceramic processing and powder technology with special attention on the description of the sintering process. A practical method for transformation of dilatometric shrinkage data into densification curves (the dependence of the sample density on sintering temperature or time) is described in detail. A new automatic procedure to recalculate sintering shrinkage data allowing the plot of the densification curve has been developed, which is presented here.

The Effect of Vuggy Porosity on Straining in Porous Media

SPE Journal ◽  
2019 ◽  
Vol 24 (03) ◽  
pp. 1164-1178 ◽  
Author(s):  
Hasan J. Khan ◽  
Maša Prodanovic ◽  
David A. DiCarlo
Keyword(s):  
Glass Beads ◽  
Surface Forces ◽  
Particle Sizes ◽  
Sintering Process ◽  
The Core ◽  
Maximum Change ◽  
Flow Experiment ◽  
The Matrix ◽  
Flow Configurations ◽  
Shape Changes

Summary A formation-damage experimental study is conducted on synthetic homogeneous and vuggy cores. Glass beads of 1.0 mm are sintered to form a uniform core with a porosity of 42%, and finer-sized glass beads (25 and 100 µm) are used as the infiltrates. Glass beads are used as the matrix and infiltrate to reduce surface forces, and the flow is gravity dominated. Dissolvable inclusions are added during the sintering process to create vugs in the core. The pore-size to vug-size ratio is 1:100. The injected-particle sizes are chosen such that straining is the dominant trapping mechanism during the flow experiment. Infiltrate particles are injected at different flow configurations, and the resultant porosity, permeability, and effluent volume are measured. The results can be summarized as follows: Vugs get up to 32% smaller caused by the flow for the infiltrate, while the maximum change in the porosity is observed at the bottom end of the core, vug shape changes to a smoother and rounded surface, and particles go deeper (8 mm more) into the formation when vugs are present, causing damage deeper inside the formation.

Influence of B2O3 on Dielectric, Mechanical, and Thermal Properties of MgO-Al2O3-SiO2 Glass-Ceramics

2019 ◽  
Vol 821 ◽  
pp. 435-439
Author(s):  
Bo Li ◽  
Ke Jing ◽  
Hai Bo Bian
Keyword(s):  
Activation Energy ◽  
Thermal Expansion ◽  
Thermal Properties ◽  
Low Temperature ◽  
Flexural Strength ◽  
Glass Ceramic ◽  
Glass Ceramics ◽  
Mechanical And Thermal Properties ◽  
Sintering Process ◽  
Low Thermal Expansion

Low temperature sintered MgO-Al2O3-SiO2 glass-ceramic with high mechanical and low thermal expansion was prepared for package. The remarkable influence of B2O3 addition on the electrical, mechanical, and thermal properties was fully investigated. A small amount of B2O3 promoted the sintering process and improved the densification of MAS. The kinetics via Kissinger method indicated that an appropriate B2O3 content decreased the activation energy and helped the occurrence of crystallization. Due to the increase of crystallinity and indialite phase, B2O3 addition significantly enhanced flexural strength and Young’s modulus. MAS doped with 3wt% B2O3 can be sintered at 900 °C and obtained good properties: σ = 229 MPa, φ = 86 GPa, α = 1.66×10-6 /°C, εr = 5.29, and tanδ = 5.9×10-4.

scholarly journals Mechanical Properties and Microstructure of W-6Ni-4Co Alloy by a Two-Step Sintering Process

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 680 ◽  
Author(s):  
Hongfeng Dong ◽  
Peiyou Li ◽  
Taotao Ai ◽  
Wenhu Li
Keyword(s):  
Mechanical Properties ◽  
Mechanical Alloying ◽  
Solid Phase ◽  
Particle Sizes ◽  
Sintering Process ◽  
Dwelling Time ◽  
Milled Powders

The mechanical properties and microstructure of W-6Ni-4Co alloy through solid phase sintering and two-step sintering process were investigated. The results demonstrated that the particle sizes of W-6Ni-4Co alloy milled powders increased firstly and decreased later during a mechanical alloying process. The shape of alloy milled powders affected that of grains in alloy by solid phase sintering. The shape of W-rich particles in the alloys changed from stripes to network, to polygonal and to subsphaeroidal finally during two-step sintering process. The mechanical properties could be attributed to the densification and microstructure of alloys, and increased during two-step sintering with short dwelling time.

Conductivity activation energy and analysis of the sintering process of dielectric ceramics

1998 ◽  
Vol 36 (5-6) ◽  
pp. 290-293 ◽  
Author(s):  
Jean-Claude M'Peko ◽  
A.Rabdel Ruiz-Salvador ◽  
Gerardo Rodrı́guez-Fuentes
Keyword(s):  
Activation Energy ◽  
Sintering Process ◽  
Conductivity Activation Energy ◽  
Dielectric Ceramics

scholarly journals Исследование механизмов уплотнения нанопорошков скуттерудитов CoSb-=SUB=-3-=/SUB=- в процессе активированного полем спекания

2020 ◽  
Vol 46 (18) ◽  
pp. 45
Author(s):  
А.С. Тукмакова ◽  
Д.Б. Щеглова ◽  
А.П. Новицкий ◽  
А.И. Воронин ◽  
В.В. Ховайло ◽  
...  
Keyword(s):  
Activation Energy ◽  
Finite Element Method ◽  
Material Parameter ◽  
Rate Sensitivity ◽  
Grain Boundary Sliding ◽  
Creep Model ◽  
Creep Process ◽  
Sintering Process ◽  
The Finite Element Method ◽  
Boundary Sliding

The densification parameters have been calculated for CoSb3 nanopowders treated within the field activated sintering. We have obtained the values of creep activation energy, strain rate sensitivity exponent and material parameter that characterize the creep process. It is concluded that densification of CoSb3 is due to the grain boundary sliding based creep. The simulation of the sintering process has been carried out using the finite element method; the change of sample sizes due to densification has been calculated using the creep model. The conformity between simulation and experimental results has been shown.

scholarly journals A practical approach for the calculation of the activation energy of the sintering

2016 ◽  
Vol 48 (3) ◽  
pp. 317-324
Author(s):  
Vaclav Pouchly ◽  
Jan Hruby ◽  
Karel Maca
Keyword(s):  
Activation Energy ◽  
Practical Approach

scholarly journals Kinetic properties and structural analysis of LaCrO3 nanoparticles

2017 ◽  
Vol 35 (2) ◽  
pp. 368-373 ◽  
Author(s):  
Morteza Enhessari ◽  
Ali Salehabadi ◽  
Asma Khoobi ◽  
Razie Amiri
Keyword(s):  
Activation Energy ◽  
Optical Properties ◽  
Structural Analysis ◽  
Sol Gel ◽  
Complexing Agent ◽  
Kinetic Properties ◽  
Particle Sizes ◽  
Xrd Pattern ◽  
Degradation Activation Energy ◽  
Stoichiometric Proportion

Abstract LaCrO3 perovskite nanopowders were successfully prepared via a sol-gel method using stoichiometric proportion of materials containing lanthanum and chromium in stearic acid complexing agent. Structural analysis of LaCrO3 indicated an octahedral framework in its XRD pattern bearing crystallite size in the range of 28 nm. The particle sizes were confirmed by morphological scanning of the sample. The optical properties of LaCrO3 nanopowders clearly indicated an interesting optical activity of LaCrO3 in the UV and visible ranges. The degradation activation energy (Ed) was calculated from the output of a moderate thermal programming profile at about 207.97 kJ·mol-1 using Kissinger equation. Capacity, impedance and AC resistance of the perovskites was obtained at 2.970 nF, 2.522 MΩ and 16.19 MΩ, respectively.

scholarly journals A Practical Approach to Forgetting in Description Logics with Nominals

2020 ◽  
Vol 34 (03) ◽  
pp. 3073-3079
Author(s):  
Yizheng Zhao ◽  
Renate Schmidt ◽  
Yuejie Wang ◽  
Xuanming Zhang ◽  
Hao Feng
Keyword(s):  
Description Logic ◽  
Description Logics ◽  
Practical Method ◽  
Practical Approach ◽  
Ontology Engineering ◽  
Success Rates ◽  
Prototype Implementation ◽  
Speed Up

This paper investigates the problem of forgetting in description logics with nominals. In particular, we develop a practical method for forgetting concept and role names from ontologies specified in the description logic ALCO, extending the basic ALC with nominals. The method always terminates, and is sound in the sense that the forgetting solution computed by the method has the same logical consequences with the original ontology. The method is so far the only approach to deductive forgetting in description logics with nominals. An evaluation of a prototype implementation shows that the method achieves a significant speed-up and notably better success rates than the Lethe tool which performs deductive forgetting for ALC-ontologies. Compared to Fame, a semantic forgetting tool for ALCOIH-ontologies, better success rates are attained. From the perspective of ontology engineering this is very useful, as it provides ontology curators with a powerful tool to produce views of ontologies.

On the Sintering Activation Energy of α-Al2O3

2008 ◽  
Vol 368-372 ◽  
pp. 686-687 ◽  
Author(s):  
Wei Quan Shao ◽  
Shaou Chen ◽  
Da Li ◽  
Ping Qi ◽  
Yong Wan ◽  
...  
Keyword(s):  
Activation Energy ◽  
Particle Size ◽  
Temperature Interval ◽  
High Purity ◽  
Powder Compact ◽  
Isothermal Condition ◽  
Particle Sizes ◽  
Higher Temperature ◽  
Lower Temperature ◽  
Increasing Temperature

The sintering activation energy of high-purity alumina powders with different particle sizes was evaluated under non-isothermal condition. It was found that, during sintering, the activation energy for the lower temperature stage is higher than that for higher temperature stage. The value of the activation energies for the powder compact with larger particle size was higher than that for the powder compact with smaller particle size. If the selected temperature interval for calculation was narrow enough, the evaluated activation energy values varied with the increasing temperature continuously.

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