The Effects of Gas Composition and Pressure on RF Plasma Sintering of MgO

1987 ◽  
Vol 98 ◽  
Author(s):  
Peter C. Kong ◽  
Y. C. Lau ◽  
E. Pfender
Keyword(s):  
Grain Growth ◽  
Charged Particles ◽  
Surface Recombination ◽  
Gas Pressure ◽  
Rf Plasma ◽  
Gas Composition ◽  
Plasma Composition ◽  
Sintering Aids ◽  
Plasma Sintering ◽  
Plasma Enthalpy

ABSTRACTRapid densification of MgO in an rf plasma without sintering aids is demonstrated. The sintered densities of MgO are sensitive to the plasma composition and gas pressure. In general, specimens are sintered to higher densities in Ar/O2 and Ar/H2O plasmas than in pure Ar plasmas. This may be explained by the effects of plasma enthalpy and surface recombination of charged particles and of atomic species. Analyses show that the evolution of the microstructures of the sintered specimens remains similar, regardless of the plasma conditions. No substantial grain growth is observed.

Grain growth kinetics in CoCrFeNi and CoCrFeMnNi high entropy alloys processed by spark plasma sintering

2019 ◽  
Vol 791 ◽  
pp. 1114-1121 ◽  
Author(s):  
M. Vaidya ◽  
Ameey Anupam ◽  
J. Vijay Bharadwaj ◽  
Chandan Srivastava ◽  
B.S. Murty
Keyword(s):  
Grain Growth ◽  
Spark Plasma Sintering ◽  
Growth Kinetics ◽  
High Entropy Alloys ◽  
High Entropy ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Grain Growth Kinetics

Preparation and Characterization of Alumina based TiNn and SiCn Composites

2002 ◽  
Vol 740 ◽  
Author(s):  
Mats Carlsson ◽  
Mats Johnsson ◽  
Annika Pohl
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Grain Growth ◽  
Ceramic Composites ◽  
Processing Route ◽  
Nano Structure ◽  
Plasma Sintering ◽  
Water Based ◽  
Spark Plasma

ABSTRACTCeramic composites containing 2 and 5vol. % of nanosized commercially available TiN and SiC particles in alumina were prepared via a water based slurry processing route followed by spark plasma sintering (SPS) at 75 MPa in the temperature range 1200–1600°C. Some of the samples could be fully densified by use of SPS already after five minutes at 1200°C and 75 MPa. The aim was to control the alumina grain growth and thus obtain different nano-structure types. The microstructures have been correlated to some mechanical properties; e.g. hardness and fracture toughness.

Effect of B4C Content on Densification Behavior of SiC-B4C Ceramics

2014 ◽  
Vol 997 ◽  
pp. 454-456
Author(s):  
Yun Long Zhang ◽  
Yu Min Zhang ◽  
Ming Hu ◽  
Xiao Gang Song
Keyword(s):  
Rare Earth ◽  
Rare Earth Oxide ◽  
Gas Pressure ◽  
Volume Shrinkage ◽  
Densification Behavior ◽  
Sintering Aids ◽  
Phase Constitution ◽  
Sintering Additives ◽  
Multi Phase ◽  
Gas Pressure Sintering

The SiC-B4C multi-phase ceramics was fabricated by gas-pressure sintering technology. The rare-earth oxide Al2O3combined with Er2O3/SiO2was served as sintering aids. The results were shown that the combination of Al2O3/Er2O3/SiO2sintering additives were effective for densification of SiC-B4C multi-phase ceramics. The influence of B4C content on the phase constitution, microstructure and densification behavior of the SiC-B4C multi-phase ceramics were detailed. The lose weight and volume shrinkage rate of SiC-B4C multi-phase ceramics had similar evolvement trend when B4C content increased. Keywords: Gas-Pressure Sintering, SiC-B4C multi-phase ceramics, densification behavior.

Effect of the Rare Earth Oxides on Sintering Behavior and Microstructure of ZrB2-SiC Ceramics

2008 ◽  
Vol 368-372 ◽  
pp. 1740-1742 ◽  
Author(s):  
Xue Ying Li ◽  
Jie Cai Han ◽  
Xing Hong Zhang ◽  
Xiao Guang Luo
Keyword(s):  
Fracture Toughness ◽  
Grain Size ◽  
Rare Earth ◽  
Grain Growth ◽  
Rare Earth Oxides ◽  
Sintering Behavior ◽  
Sintering Aids ◽  
Sic Ceramics ◽  
Sic Composites ◽  
And Control

In this study, two rare earth oxides, Y2O3 and La2O3, are used as the additives in the sintering of ZrB2-SiC composites to improve the sinterability and control development of microstructure during densification. The results show that the use of rare earth oxides (5vol.%) improves the powder sinterability, hindered excessive growth of matrix particles and increase fracture toughness of ZrB2-SiC composites, in comparison to ZrB2-SiC with additions free. Nearly full dense materials are obtained by hot pressing at 1900°C. XRD analyses indicate that lanthanum-containing phases were formed in the composite with La2O3. Microstructure observations by SEM reveal that the grain size of ZrB2-SiC with Y2O3 and La2O3 composites are less than the sample without additives, which indicates Y2O3 and La2O3 may restrain the grain growth and increase the fracture toughness. The fracture toughness of ZrB2-SiC composites with Y2O3 and La2O3 reached 5.0MPa·m1/2 and 5.5MPa·m1/2 respectively. Therefore, the additive Y2O3 and La2O3 are very effective as sintering aids for the ZrB2-SiC composite.

The Effect of Sb Content on Spark Plasma Sintered High-Density Antimony-Doped Tin Oxide Ceramics

2011 ◽  
Vol 687 ◽  
pp. 204-208 ◽  
Author(s):  
Qi Zhong Li ◽  
Dong Ming Zhang ◽  
Guo Qiang Luo ◽  
Cheng Zhang Li ◽  
Qiang Shen ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Tin Oxide ◽  
Sintering Temperature ◽  
Glass Melting ◽  
High Density ◽  
Oxide Ceramics ◽  
Sintering Aids ◽  
Maximum Value ◽  
Plasma Sintering ◽  
Spark Plasma

Spark plasma sintering (SPS) is a newly developed technique that enables poorly sinterable tin oxide powder to be fully densified. Sintering without sintering aids is of great importance when SnO2ceramics are used as electrodes in the glass melting industry and aluminum electrometallurgy. Dense and good-conductive Antimony-doped SnO2 ceramics can be achieved by SPS at a lower sintering temperature and in a shorter time. When the Sb2O3concentration is 1.0 mol%, the densities of the samples reach their maximum value, which is 98.2% of the theoretical value. When the content of Sb2O3was 2.44mol%, SnO2ceramics with densities 97.6% can be obtained at 800°C-1000°C, and the resistivity was about 5.19×10-2Ω.cm at the sintering temperature of 1000°C. Defined amount of Sb3+used in our research are beneficial to low the sintering temperature and promote the densification of SnO2ceramics

NdFeB Type Magnets Produced by Spark Plasma Sintering

2014 ◽  
Vol 802 ◽  
pp. 585-589 ◽  
Author(s):  
M. Alberteris Campos ◽  
N. Vicente ◽  
I.F. Machado ◽  
K.S.T. de Souza ◽  
D. Rodrigues ◽  
...  
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Spark Plasma Sintering ◽  
Alloying Element ◽  
Consolidation Process ◽  
Ndfeb Magnets ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Typical Temperature

The shortage of dysprosium as an alloying element has directed the research on the grain size refining of NdFeB, since higher coercivities can be obtained by decreasing the grain size, without Dy addition. The Spark Plasma Sintering (SPS) is a consolidation process which allows densification at lower temperatures and shorter dwell times of sintering, thus avoiding the grain growth. Therefore, the typical temperature of sintering of NdFeB magnets can be decreased from 1050°C to around 800°C, as it was evidenced by means of SPS shrinkage curves and the high densified microestructure obtained in this work.

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