Plasma Sintering of Ceramics

1983 ◽  
Vol 24 ◽  
Author(s):  
D. Lynn Johnson ◽  
Wayne B. Sanderson ◽  
Eric L. Kemer ◽  
Jennifer Knowlton
Keyword(s):  
Grain Size ◽  
Hollow Cathode ◽  
High Density ◽  
Hollow Cathode Discharge ◽  
Microwave Induced Plasma ◽  
Fine Grain ◽  
Plasma Sintering

ABSTRACTAlumina rods doped with MgO have been sintered by rapid translation through three plasma devices, namely a microwave induced plasma, a hollow cathode discharge, and an RF induction coupled plasma. Rapid densification to high density and fine grain size was observed. Some similarities and significant differences existed among the different devices.

Effect of Sintering Temperature on Microstructure and Mechanical Properties of Nanocrystalline Aluminum 5083 Alloy

2015 ◽  
Vol 782 ◽  
pp. 113-118
Author(s):  
Ying Mei Teng ◽  
Zhao Hui Zhang ◽  
Zi Zhou Yuan
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Compressive Strength ◽  
Sintering Temperature ◽  
Initial Pressure ◽  
Fine Grain ◽  
Microstructure And Mechanical Properties ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Bulk Nanocrystalline

The bulk nanocrystalline (NC) aluminum (Al) 5083 was synthesized by spark plasma sintering (SPS) technique with low initial pressure of 1 MPa, high holding pressure of 300 MPa and holding time of 4 min at different sintering temperatures, using surface passivated nanopowders. The effect of sintering temperature on microstructure and mechanical properties of the bulk NC Al 5083 were investigated. Results indicate that the density, grain size, the hardness and the compressive strength of the bulk NC Al 5083 increase with an increase in sintering temperature. The mechanical properties of the material are greatly improved due to the fine grain size. The bulk NC Al 5083 sintered at 723 K has the highest micro-hardness of 2.37 GPa and the best compressive strength of 845 MPa.

Effect of Grain Size on Phase Transitions and Dielectric Properties of Nano-Crystalline Barium Titanate Ceramics

2012 ◽  
Vol 602-604 ◽  
pp. 192-196
Author(s):  
Li Ming Wang ◽  
Xiang Yun Deng ◽  
Hai Tao Zhang ◽  
Jian Bao Li ◽  
Di Chen ◽  
...  
Keyword(s):  
Phase Transition ◽  
Grain Size ◽  
Phase Transitions ◽  
Barium Titanate ◽  
Fine Grain ◽  
Nano Crystalline ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Spark Plasma ◽  
Titanate Ceramics

Barium titanate (BaTiO3) ceramics with grain size varied from 1000 to 8 nm were prepared by two step sintering method (TSS) and spark plasma sintering (SPS), respectively. Mixture structures of BaTiO3 ceramics were proved by in-situ temperature high resolution x-ray diffraction. Multiple ferroelectric domains present in nano-crystalline BaTiO3 ceramics were observed by transmission electron microscope. The evolution of phase transitions supported the existence of intrinsic mechanism. Dielectric loss of fine grain size BaTiO3 was higher than coarse grain size during Curie phase transition due to diffuse phase transition and grain boundary effects.

RF Plasma CVD Using Hollow Cathode Discharge

1988 ◽  
Vol 129 ◽  
Author(s):  
Shin Araki ◽  
Hideki Kamaji ◽  
Kazuo Norimoto
Keyword(s):  
Hollow Cathode ◽  
Low Pressure ◽  
High Density ◽  
Hollow Cathode Discharge ◽  
Rf Plasma ◽  
High Deposition Rate ◽  
Plasma Cvd ◽  
Plasma Damage ◽  
Discharge Electrode ◽  
Density Plasma

ABSTRACTWe have made a-Si photoreceptors at low pressure to prevent the formation of SimHn powders and by separating the growing surface from the high density plasma. A new plasma CVD method using a hollow-cathode discharge, where the discharge electrode is the cathode, is described. There is a hollow region in the discharge electrode. Hollow-cathode discharge enables a high density plasma to form at low pressure. The gas is decomposed in the hollow cathode preventing plasma damage to the film. This method allows us to achieve a high deposition rate (10 µm/h) and good quality films for photoreceptors.

Production of High-Density Radio-Frequency Plasma Source by Ring-Shaped Hollow-Cathode Discharge at Various Trench Shapes

2013 ◽  
Vol 41 (8) ◽  
pp. 1856-1862 ◽  
Author(s):  
Yasunori Ohtsu ◽  
Yoshiki Yahata ◽  
Johji Kagami ◽  
Yasushi Kawashimo ◽  
Tatsuya Takeuchi
Keyword(s):  
Radio Frequency ◽  
Hollow Cathode ◽  
Plasma Source ◽  
High Density ◽  
Hollow Cathode Discharge ◽  
Radio Frequency Plasma ◽  
Frequency Plasma

Mechanical Properties of Rapidly Solidified MG-ZN Alloys

1985 ◽  
Vol 58 ◽  
Author(s):  
D. Themines ◽  
W. Riehemann ◽  
W. Henning ◽  
B.L. Mordike
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Significant Contribution ◽  
Discontinuous Precipitation ◽  
High Density ◽  
Quenching Rate ◽  
Fine Grain ◽  
Rapidly Quenched Alloys ◽  
Precipitation Behaviour ◽  
Rapidly Solidified

Rapidly quenched alloys differ from those that are conventionally solidified in the degree of supersaturation, the microstructure and the grain size. The quenching rate can thus be used to modify the mechanical properties. A fine grain size increases the hardness and ductility. The precipitation behaviour is modified by the high density of heterogeneous nuclei or high density of quenched in defects in that the rate of precipitation is increased. Discontinuous precipitation should make a significant contribution to the increase in strength as a result of the fine grain size.

Grain Growth, Microstructure and Property of Ultrafine WC-Co Alloy by Spark Plasma Sintering

2007 ◽  
Vol 558-559 ◽  
pp. 959-963 ◽  
Author(s):  
Lan Sun ◽  
Cheng Chang Jia ◽  
Min Xian ◽  
Rui Jun Cao
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Spark Plasma Sintering ◽  
Abnormal Grain Growth ◽  
Full Density ◽  
Fine Grain ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Increasing Temperature ◽  
New Phase

In order to control WC grain size and get a microstructure with fine grain size during the sintering process, WC grain growth in WC-Co cemented carbide was investigated. The possible reason on the grain growth was showed which includes the normal grain growth (NGG) and the abnormal grain growth (AGG). We adopted the SPS (spark plasma sintering) to sinter nanometer WC-Co powder, the range of temperature was 1100 -1250 °C, the pressure was 40MPa, and sintering time was 5min. In this paper, we discuss the density, hardness, microstructures and grain sizes of the sintered samples. The results showed that during the process sintering WC-Co powder, there are two kinds of growths. XRD investigation of the WC–Co samples spark plasma sintered to full density revealed that no new phase was created. Through the observed microstructure of the sintered samples, we analyzed the reason of the abnormal grain growth of WC grain. The density and hardness of samples were increased with increasing temperature.

Optical Property of Spark Plasma Sintered Translucent AlN Ceramics

2007 ◽  
Vol 336-338 ◽  
pp. 545-548
Author(s):  
Y. Xiong ◽  
Zheng Yi Fu ◽  
Hang Wang
Keyword(s):  
Grain Size ◽  
Optical Property ◽  
Grain Boundaries ◽  
Spark Plasma Sintering ◽  
Secondary Phases ◽  
Fine Grain ◽  
Sintering Additive ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Good Optical Property

Translucent AlN ceramics were fabricated using spark plasma sintering (SPS) technique with 3wt% CaF2 as sintering additive. The samples achieved 52.4% maximum transmittance in medium IR region after 10 min holding time by spark plasma sintering at 1800°C and 30 MPa pressure in N2. The results from XRD, SEM, TEM and EDX showed that the sintered bodies were densely compacted and highly pure with fine grain size and uniform microstructures. No secondary phases were observed at the grain boundaries and triple grain junctions, which guaranteed good optical property of the sintered bodies.

Aspects of microanalysis in a transmission electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 510-511
Author(s):  
R. Sinclair ◽  
B.E. Jacobson
Keyword(s):  
Grain Size ◽  
Electron Beam ◽  
Electron Microscope ◽  
Chemical Analysis ◽  
Transmission Electron Microscope ◽  
Vapor Deposition ◽  
Critical Currents ◽  
X Ray ◽  
Fine Grain ◽  
Transmission Electron

INTRODUCTIONThe prospect of performing chemical analysis of thin specimens at any desired level of resolution is particularly appealing to the materials scientist. Commercial TEM-based systems are now available which virtually provide this capability. The purpose of this contribution is to illustrate its application to problems which would have been intractable until recently, pointing out some current limitations.X-RAY ANALYSISIn an attempt to fabricate superconducting materials with high critical currents and temperature, thin Nb3Sn films have been prepared by electron beam vapor deposition [1]. Fine-grain size material is desirable which may be achieved by codeposition with small amounts of Al2O3 . Figure 1 shows the STEM microstructure, with large (∽ 200 Å dia) voids present at the grain boundaries. Higher quality TEM micrographs (e.g. fig. 2) reveal the presence of small voids within the grains which are absent in pure Nb3Sn prepared under identical conditions. The X-ray spectrum from large (∽ lμ dia) or small (∽100 Ǻ dia) areas within the grains indicates only small amounts of A1 (fig.3).

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