Spark Plasma Sintering of α-Si3N4 Ceramics with MgO-Al2O3 as Sintering Additives

2007 ◽  
Vol 351 ◽  
pp. 176-179 ◽  
Author(s):  
Fa Qiang Yan ◽  
Fei Chen ◽  
Qiang Shen ◽  
Lian Meng Zhang
Keyword(s):  
Relative Density ◽  
Spark Plasma Sintering ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Close Correlation ◽  
Liquid Phase Sintering ◽  
Sintering Additives ◽  
Sintering Mechanism ◽  
Plasma Sintering ◽  
Spark Plasma

In the present study, α-Si3N4 is prepared by using MgO and Al2O3 as the sintering additives and spark plasma sintering (SPS) technique. The SPS sintering mechanism is discussed. The relationship between the content of sintering additives, sintering temperature and relative densities of the samples is analyzed. The results suggest that when the sintering temperature is 1300-1500°C, the content of sintering additives is 6wt.%-10wt.%, the relative density of sintered samples is 64%-96%. When the sintering temperature reaches 1400°C, the content of sintering additives is 10%, the samples can be fully dense sintered and the relative density can be up to 95%. The sintering mechanism is liquid phase sintering. The bending strength of the sintered samples is 50-403MPa and has a close correlation with the relative density.

Effect of Spark Plasma Sintering on the Microstructure Evolution and Properties of M3:2 High-Speed Steel

2014 ◽  
Vol 788 ◽  
pp. 329-333
Author(s):  
Rui Zhou ◽  
Xiao Gang Diao ◽  
Jun Chen ◽  
Xiao Nan Du ◽  
Guo Ding Yuan ◽  
...  
Keyword(s):  
Powder Metallurgy ◽  
Spark Plasma Sintering ◽  
High Speed ◽  
Bending Strength ◽  
Sintering Temperature ◽  
High Speed Steel ◽  
Continuous Heating ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
The Impact

Effects of sintering temperatures on the microstructure and mechanical performance of SPS M3:2 high speed steel prepared by spark plasma sintering was studied. High speed steel sintering curve of continuous heating from ambient temperature to 1200°C was estimated to analyze the sintering processes and sintering temperature range. The sintering temperature within this range was divided into groups to investigate hardness, relative density and microstructure of M3:2 high-speed steel. Strip and quadrate carbides were observed inside the equiaxed grains. SPS sintering temperature at 900°C can lead to nearly full densification with grain size smaller than 20μm. The hardness and bending strength are higher than that of the conventionally powder metallurgy fabricated ones sintered at 1270°C. However, fracture toughness of the high speed steel is lower than that of the conventional powder metallurgy steels. This can be attributed to the shape and distribution of M6C carbides which reduce the impact toughness of high speed steels.

scholarly journals Mechanical Milling-Assisted Spark Plasma Sintering of Fine-Grained W-Ni-Mn Alloy

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1323 ◽  
Author(s):  
Yanlin Pan ◽  
Daoping Xiang ◽  
Ning Wang ◽  
Hui Li ◽  
Zhishuai Fan
Keyword(s):  
Spark Plasma Sintering ◽  
Mechanical Milling ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Interface Fracture ◽  
Composite Powders ◽  
Fine Grained ◽  
Plasma Sintering ◽  
Binding Phase ◽  
Spark Plasma

Fine-grained W-6Ni-4Mn alloys were fabricated by spark plasma sintering (SPS) using mechanical milling W, Ni and Mn composite powders. The relative density of W-6Ni-4Mn alloy increases from 71.56% to 99.60% when it is sintered at a low temperature range of 1000–1200 °C for 3 min. The spark plasma sintering process of the alloy can be divided into three stages, which clarify the densification process of powder compacts. As the sintering temperature increases, the average W grain size increases but remains at less than 7 µm and the distribution of the binding phase is uniform. Transmission electron microscopy (TEM) observation reveals that the W-6Ni-4Mn alloy consists of the tungsten phase and the γ-(Ni, Mn, W) binding phase. As the sintering temperature increases, the Rockwell hardness and bending strength of alloys initially increases and then decreases. The optimum comprehensive hardness and bending strength of the alloy are obtained at 1150 °C. The main fracture mode of the alloys is W/W interface fracture.

scholarly journals Characterization of Multiwalled Carbon Nanotube-Reinforced Hydroxyapatite Composites Consolidated by Spark Plasma Sintering

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Duk-Yeon Kim ◽  
Young-Hwan Han ◽  
Jun Hee Lee ◽  
Inn-Kyu Kang ◽  
Byung-Koog Jang ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Relative Density ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Multiwalled Carbon Nanotube ◽  
Multiwalled Carbon ◽  
Pull Out ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Mwnt Content

Pure HA and 1, 3, 5, and 10 vol% multiwalled carbon nanotube- (MWNT-) reinforced hydroxyapatite (HA) were consolidated using a spark plasma sintering (SPS) technique. The relative density of pure HA increased with increasing sintering temperature, but that of the MWNT/HA composite reached almost full density at 900°C, and then decreased with further increases in sintering temperature. The relative density of the MWNT/HA composites increased with increasing MWNT content due to the excellent thermal conductivity of MWNTs. The grain size of MWNT/HA composites decreased with increasing MWNT content and increased with increasing sintering temperature. Pull-out toughening of the MWNTs of the MWNT/HA composites was observed in the fractured surface, which can be used to predict the improvement of the mechanical properties. On the other hand, the existence of undispersed or agglomerate MWNTs in the MWNT/HA composites accompanied large pores. The formation of large pores increased with increasing sintering temperature and MWNT content. The addition of MWNT in HA increased the hardness and fracture toughness by approximately 3~4 times, despite the presence of large pores produced by un-dispersed MWNTs. This provides strong evidence as to why the MWNTs are good candidates as reinforcements for strengthening the ceramic matrix. The MWNT/HA composites did not decompose during SPS sintering. The MWNT-reinforced HA composites were non-toxic and showed a good cell affinity and morphologyin vitrofor 1 day.

Effects of Processing Parameters of SPS on the Densification and Texture of LaPO4 Ceramics

2008 ◽  
Vol 368-372 ◽  
pp. 1059-1061 ◽  
Author(s):  
Ai Bing Du ◽  
Zhi Xue Qu ◽  
Chun Lei Wan ◽  
Ruo Bing Han ◽  
Wei Pan
Keyword(s):  
Relative Density ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Processing Parameters ◽  
Preferred Orientation ◽  
Holding Time ◽  
Plasma Sintering ◽  
Spark Plasma

Spark plasma sintering was used to fabricate the LaPO4 ceramics and the effect of SPS holding time and sintering temperature on the densification and texture of LaPO4 ceramics were studied. The results revealed that holding time had no obvious influence on the densification of LaPO4 ceramics under the present process. The density increases with the increase of sintering temperature, when it reached 1350°C, the relative density kept nearly constant of 98.6 %. The preferred orientation of LaPO4 ceramics approximately increases with the increase of sintering temperature, but contrary impact in holding time.

Fabrication of TiAl Intermetallic by Spark Plasma Sintering

2007 ◽  
Vol 336-338 ◽  
pp. 1050-1052 ◽  
Author(s):  
Hai Tao Wu ◽  
Yun Long Yue ◽  
Wei Bing Wu ◽  
Hai Yan Yin
Keyword(s):  
Mechanical Properties ◽  
Intermetallic Compounds ◽  
Spark Plasma Sintering ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Three Point Bending ◽  
The Poor ◽  
High Relative Density ◽  
Plasma Sintering ◽  
Spark Plasma

The γ-TiAl intermetallic compounds were produced at the temperature ranging from 850°C to 1050°C by the Spark Plasma Sintering (SPS) process. The effects of sintering temperature and holding time on the mechanical properties of γ-TiAl intermetallic compounds were investigated. The γ-TiAl intermetallic compounds sintered at 1050°C for 10 min showed a high relative density more than 98%, and had the best three-point bending strength of 643MPa, fracture toughness of 12 MPa·m1/2 and microhardness of 560MPa. The microstructural observations indicated typical characteristics of intergranular fracture, which meant the poor ductility of γ-TiAl intermetallic compounds.

Spark Plasma Sintering and Characterization of WC-Co-cBN Composites

2014 ◽  
Vol 616 ◽  
pp. 194-198 ◽  
Author(s):  
Jian Feng Zhang ◽  
Rong Tu ◽  
Takashi Goto
Keyword(s):  
Fracture Toughness ◽  
Phase Transformation ◽  
Relative Density ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Moderate Pressure ◽  
Plasma Sintering ◽  
Spark Plasma

WC-Co-cBN composites were consolidated by SPS at 1373 to 1673 K under a moderate pressure of 100 MPa. The addition of cBN increased the starting and finishing temperature of shrinkage and decreased the relative density of WC-Co. The relative density of WC-(10-20 vol%) cBN composites was about 97-100% at 1573 K and decreased with increasing the sintering temperature to 1673 K due to the phase transformation of cBN to hBN. The highest hardness and fracture toughness of WC-Co-20 vol% cBN composite sintered at 1573 K were 23.2 GPa and 8.0 MP m1/2, respectively.

scholarly journals Effect of Doped CeO with Si3N4 Powders on the Densification Mechanism During

2021 ◽  
Author(s):  
Yao Liu
Keyword(s):  
Liquid Phase ◽  
Relative Density ◽  
Stress Exponent ◽  
Spark Plasma Sintering ◽  
Liquid Phase Sintering ◽  
Creep Model ◽  
Stress Regime ◽  
Densification Mechanism ◽  
Plasma Sintering ◽  
Spark Plasma

Abstract The densification mechanism of doped CeO with Si3N4 powder during Spark Plasma Sintering (SPS) was investigated under temperatures ranging from 1500 to 1750 °C at soaking pressures of 30, 40, 50 MPa. Results showed that the relative density of Si3N4 ceramics sintered at 1650 °C and 30 MPa was 97.9%. A creep model was employed to determine the mechanism, which can be interpreted on the basis of the stress exponent (n). The results showed that the mechanism was controlled by liquid phase sintering at low effective stress regime (n=1).

Liquid Phase Sintering of α-Si3N4 by Spark Plasma Sintering

2007 ◽  
Vol 336-338 ◽  
pp. 1062-1064 ◽  
Author(s):  
Fa Qiang Yan ◽  
Fei Chen ◽  
Qiang Shen ◽  
Lian Meng Zhang
Keyword(s):  
Liquid Phase ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Liquid Phase Sintering ◽  
Sintering Behavior ◽  
Sintering Aids ◽  
Factors Influencing ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Si3n4 Ceramics

In this study, spark plasma sintering (SPS) was applied to prepare α-Si3N4 ceramics of different densities with magnesia, silicon dioxide, alumina as the sintering aids. The sintering behavior and liquid phase sintering (LPS) mechanism were discussed and the factors influencing the density of the prepared samples were analyzed. Microstructures of sintered samples were observed and the phase compositions were analyzed. The results showed that α-Si3N4 ceramics can be sintered by SPS based on the reaction among α-Si3N4 and sintering additives which lead to the liquid phase and the density can be well controlled from 2.48 to 3.09 g/cm3 while the content of the sintering aids changes from 10% to 28.5% and sintering temperature from 1400°C to 1500°C.

Fabrication Processes and Properties of Highly Pure MgAlON Materials

2007 ◽  
Vol 561-565 ◽  
pp. 543-546 ◽  
Author(s):  
Qing Huang ◽  
Yong Huang ◽  
Chang An Wang ◽  
Hou Xing Zhang
Keyword(s):  
Spark Plasma Sintering ◽  
Open Porosity ◽  
Single Phase ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Hot Press ◽  
Plasma Sintering ◽  
Short Period ◽  
Spark Plasma ◽  
Hot Press Sintering

In this paper, the MgAlON ceramic was fabricated by Spark Plasma Sintering (SPS) and hot press sintering respectively. The results showed that highly pure and single-phase MgAlON could be fabricated at lower sintering temperature in a short period through SPS process, compared with the conventional Hot Press sintering (HP) process. The bending strength of MgAlON specimens prepared by SPS process was higher than 500MPa while bending strength of HP specimens was much lower. The open porosity was almost eliminated in SPS MgAlON specimens. Spark Plasma Sintered MgAlON had a single phase of MgAlON while Hot Press Sintered MgAlON had major MgAlON and minor AlN and Al2O3.

Reactive Spark Plasma Sintering of Si3N4 Based Composites

2010 ◽  
Vol 62 ◽  
pp. 185-190 ◽  
Author(s):  
Zeynep Taslicukur ◽  
Filiz Çinar Şahin ◽  
Gultekin Goller ◽  
Yücel Onüralp ◽  
Nilgun Kuskonmaz
Keyword(s):  
Spark Plasma Sintering ◽  
Ceramic Composite ◽  
Sintering Temperature ◽  
Uniaxial Pressure ◽  
Si3n4 Ceramic ◽  
Sem Images ◽  
Sintering Additives ◽  
Plasma Sintering ◽  
Spark Plasma

Si3N4 based composites containing different amounts of SiC and SiAlON were produced by reactive spark plasma sintering of Si3N4, SiO2 and C black. Y2O3 and AlN were added as sintering additives. The SPS process was carried out at sintering temperature of 1650 0C for 5 min with uniaxial pressure of 40 MPa in a nitrogen atmosphere.The mechanic properties and morphology of Si3N4 ceramic composite were determined. Microstructures of the sintered samples were observed by SEM images and phase compositions were analysed by XRD.

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