Influence of Powder Characteristics on Sintering of AlN Ceramics

2007 ◽  
Vol 280-283 ◽  
pp. 1409-1412 ◽  
Author(s):  
Jin Yu Qiu ◽  
Koji Watari ◽  
Yuji Hotta ◽  
Kenshi Mitsuishi
Keyword(s):  
Final Stage ◽  
Sintering Temperature ◽  
Sintering Behavior ◽  
Particle Sizes ◽  
Sintering Aid ◽  
Surface Areas ◽  
Initial Stage ◽  
Primary Particles ◽  
Powder Characteristics ◽  
Specific Surface Areas

The sintering behavior of AlN powders with different particle sizes and specific surface areas was investigated in the present work. 4.5-8.0mass% of the as-synthesized sintering aid from the Li2O-Y2O3-CaO system was added to these AlN powders, and they were then fired at 1400-1650oC for 6h. At the initial stage of sintering the fine AlN powder, it was recognized that sintering of primary particles occurred in agglomerations. With an increase of firing temperature, particles were rearranged and grains grew rapidly at the final stage. On contrary, in sintering of samples using the coarse AlN powder, the densification increased with raising sintering temperatures slowly, and the sintering temperature higher than 1650oC was required to obtain densified specimens.

Sintering behavior and ionic conductivity of Li1.5Al0.5Ti1.5(PO4)3 synthesized with different precursors

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Bambar Davaasuren ◽  
Qianli Ma ◽  
Alexandra von der Heiden ◽  
Frank Tietz
Keyword(s):  
Grain Size ◽  
Solid State ◽  
Ionic Conductivity ◽  
Solid State Reaction ◽  
Sintering Temperature ◽  
Sintering Behavior ◽  
Homogeneous Microstructure ◽  
Micro Cracks ◽  
Primary Particles ◽  
Total Ionic Conductivity

Abstract Li1.5Al0.5Ti1.5(PO4)3 (LATP) powders were prepared from different NO x -free precursors using an aqueous-based solution-assisted solid-state reaction (SA-SSR). The sintering behavior, phase formation, microstructure and ionic conductivity of the powders were explored as a function of sintering temperature. The powders showed a relatively narrow temperature windows in which shrinkage occurred. Relative densities of 95% were reached upon heating between 900 and 960 °C. Depending on the morphological features of the primary particles, either homogeneous and intact microstructures with fine grains of about <2 µm in size or a broad grain size distribution, micro-cracks and grain cleavages were obtained, indicating the instability of the microstructure. Consequently, the ceramics with a homogeneous microstructure possessed a maximum total ionic conductivity of 0.67 mS cm−1, whereas other ceramics reached only 0.58 mS cm−1 and 0.21 mS cm−1.

Influence of compaction and degassing on the properties of submicron WCCo produced by the PPS method

2019 ◽  
Vol 108 ◽  
pp. 5-12
Author(s):  
JOANNA WACHOWICZ ◽  
MARCIN ROSIŃSKI ◽  
RADOSŁAW ZIELIŃSKI ◽  
TOMASZ TRUSZKOWSKI
Keyword(s):  
Fracture Toughness ◽  
Heating Rate ◽  
Final Stage ◽  
Sintering Temperature ◽  
Cobalt Content ◽  
Operation Temperature ◽  
Plasma Sintering ◽  
Initial Stage ◽  
Temperature Load ◽  
Pulse Plasma Sintering

Influence of compaction and degassing on the properties of submicron WCCo produced by the PPS method. The present study is concerned with the effect of the parameters of the degassing operation (temperature, load and heating rate) conducted at the initial stage of the Pulse Plasma Sintering (PPS) process and the sintering temperature at the final stage of the process, on the properties and microstructure of WCCo with a 6wt% cobalt content sintered by this method. The results of the study have shown that when the heating rate is too high, the material obtained is porous. In most experiments, the sintering temperature of 1050°C appeared to be too low to obtain WCCo composites with density close to the theoretical value (GT). Sintering at the temperature increased to 1070°C yielded sinters with density above 99%GT, with hardness of about 1900 HV30 and fracture toughness KIC=9.3 MNm-3/2.

Sintering behavior and thermoelectric properties of LaCoO3 ceramics with Bi2O3–B2O3–SiO2 as a sintering aid

RSC Advances ◽  
2014 ◽  
Vol 4 (94) ◽  
pp. 51995-52000 ◽  
Author(s):  
Jiao Han ◽  
Ying Song ◽  
Xue Liu ◽  
Fuping Wang
Keyword(s):  
Thermoelectric Properties ◽  
Sintering Temperature ◽  
Low Cost ◽  
Thermoelectric Performance ◽  
Sintering Behavior ◽  
Sintering Aid

Bi2O3–B2O3–SiO2 could remarkably reduce the sintering temperature of LaCoO3 ceramics to 950 oC, providing a low cost and facile approach to improve the sinterability and thermoelectric performance of oxides.

Low-Temperature Sintering of ZnO–TiO2 Ceramics

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Zhengwei Nie ◽  
Yuyi Lin ◽  
Feixue Wang
Keyword(s):  
Low Temperature ◽  
Vanadium Pentoxide ◽  
Material Properties ◽  
Sintering Temperature ◽  
Theoretical Density ◽  
Sintering Behavior ◽  
Low Temperature Sintering ◽  
Sintering Aid

Vanadium pentoxide (V2O5) was chosen as a sintering aid to lower the sintering temperature of the ZnO–TiO2 system. The effect of V2O5 on the sintering behavior and material properties of ZnO–TiO2 ceramics and cermets made of ZnO–TiO2 ceramics and copper (Cu) was investigated as a function of V2O5 percentage and sintering temperature. Densities and hardness of the specimens were improved with an increase of V2O5 up to 2 wt. %. The sintering temperature of the specimens can be reduced to below 1000 °C. The properties of ZnO–TiO2 ceramics and cermets made from ZnO–TiO2 ceramics and Cu with V2O5 are strongly dependent on the sintering temperature. The density of ZnO–TiO2 ceramics and cermets was increased up to 95%, 90% of theoretical density at 900–920 °C, 960–1000 °C, respectively, for 4 hrs.

scholarly journals Solution combustion synthesis and sintering behavior of porous MgAl2O4 powders

2010 ◽  
Vol 42 (2) ◽  
pp. 133-141 ◽  
Author(s):  
J.H. Bai ◽  
J.C. Liu
Keyword(s):  
Particle Size ◽  
Specific Surface ◽  
Solution Combustion Synthesis ◽  
Molar Ratio ◽  
Sintering Behavior ◽  
Solution Combustion ◽  
Structure Characteristics ◽  
Surface Areas ◽  
Combustion Route ◽  
Specific Surface Areas

Porous MgAl2O4 powders were synthesized with a solution combustion route using a mixture of glycine and urea with the glycine/urea molar ratio of 2/9 as fuel. For the comparison purpose, denser powders were also combustion synthesized using urea as fuel. The porous/denser structure, characteristics (e.g. crystallite size and specific surface areas) and sinterability of the two powders were investigated in detail. Experimental results disclosed that the as-prepared porous powders exhibited a much lower degree of agglomeration, smaller average agglomerate particle size and larger surface areas and thus far higher sintering behavior than the denser powders.

Sintering Behavior and Dielectric Properties of BZN Ceramics Coated by Precursor Solution of CuSO4

2012 ◽  
Vol 476-478 ◽  
pp. 1058-1061
Author(s):  
Qian Li ◽  
Biao Jin ◽  
Jin Liang Huang ◽  
Yong Jun Gu ◽  
Li Hua Li ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Ceramic Composite ◽  
Sintering Temperature ◽  
Negative Impact ◽  
Precursor Solution ◽  
Sintering Behavior ◽  
Coating Technology ◽  
Sintering Aid ◽  
Phase Structures ◽  
Ceramic Samples

(Bi1.5Zn0.5)(Zn0.5Nb1.5)O7 (BZN) ceramic samples were prepared by solid state reaction, In order to reduce the sintering temperature of BZN ceramic we have used liquid coating technology to dope CuO by precursor solution of CuSO4. The sintering behavior, microstructures, phase structures, and dielectric properties were studied. The process reduces the amount of sintering aid and minimized the negative impact of sintering aid on dielectric properties. A ceramic composite which could be sintered well at 900°C and showed good dielectric properties of εr=161,tanδ=0.005 and TCF=-398ppm/°C（1MHz）was obtained when 0.5mol/l CuSO4 was added to the (Bi1.5Zn0.5)(Zn0.5Nb1.5)O7 ceramic.

Dynamic Consolidation of Ceramic Powders: Practicalities, Problems, and Prospects

1983 ◽  
Vol 24 ◽  
Author(s):  
William H. Gourdin
Keyword(s):  
Cohesive Crack ◽  
Particle Sizes ◽  
Ceramic Powders ◽  
Complex Interplay ◽  
Surface Areas ◽  
Technological Potential ◽  
All Ceramic ◽  
Dynamic Consolidation ◽  
Powder Characteristics ◽  
Powder Compacts

ABSTRACTI present an assessment of the technological potential ofshock wave consolidationof ceramic powders as a technique for producing well-bonded, uniform, crack-free monoliths. Current compaction methods are briefly reviewed and the characteristics of the consolidated material are presented. The shock and release histories experienced by powder compacts in simple compaction assemblies are complex and I conclude that such simple assemblies are unlikely to yield structurally sound bodies. Control of the stress history over the entire loading cycle is necessary if the tensile stresses which develop during release are to be reduced to acceptable levels. Such exacting control is difficult to achieve, and becomes increasingly difficult as the peak stresses are increased. The powder must therefore be sufficiently plastic at moderate stresses to permit densification and bonding of the compact without destruction of the compact during release. Not all ceramic powders will satisfy this criterion. Local microstructural modification, including interfacial melting, is limited by the fine particle sizes and large surface areas of many ceramic powders. Production of cohesive, crack-free bodies thus depends upon a complex interplay between shock history, material properties, and powder characteristics which is poorly understood. I conclude that the technology of dynamic consolidation of ceramic powders will be difficult to develop and will have limited applications.

Preparation and Sintering of Nano-Sized W-Ni-Fe Powder by Sol-Spray-Drying Process

2007 ◽  
Vol 534-536 ◽  
pp. 1409-1412 ◽  
Author(s):  
Jing Lian Fan ◽  
Tao Liu ◽  
Yun Zhu Ma ◽  
Hui Chao Cheng
Keyword(s):  
Spray Drying ◽  
Sintering Temperature ◽  
Reduction Process ◽  
Formation Condition ◽  
Sintering Behavior ◽  
Second Phase ◽  
Drying Process ◽  
Mixed Powder ◽  
Powder Characteristics ◽  
Full Densification

In this paper, less than 50nm nano-sized W-Ni-Fe composite powder was prepared by Sol-Spray-Drying Process. The preparing processes such as sol formation condition, reduction process of the procusor were studied in detail. The powder characteristics and sintering behavior of the powders were also studied. The powder is nearly spherical and it has good sinterability. In comparison with traditional micron mixed powder consisting of same composition, the melting temperature of the second phase lowered about 70°C, and the sintering temperature for nearly full densification was about 1390°C, which lowered more than 100°C.The effects of rare earth on sintering of the alloy were discussed.

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