Research on Two Sintered Techniques of Nanometer WC-Co Powder

2007 ◽  
Vol 534-536 ◽  
pp. 593-596 ◽  
Author(s):  
Lan Sun ◽  
Cheng Chang Jia ◽  
Hua Tang
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Spark Plasma Sintering ◽  
Hot Pressing ◽  
Sintering Temperature ◽  
Grain Sizes ◽  
Sintering Time ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Hot Pressing Sintering

This paper concerned with SPS (spark plasma sintering), hot pressing of sinter nanometer WC-Co powder and discussed the density, hardness, microstructures and grain sizes of the alloys sintered by different styles. The results showed that SPS could lower the sintering temperature, increased the density and circumscribed the growth of grain size of WC. Hot pressing sintering could produce high density alloys and play well on the grain growth, but its sintering temperature and sintering time were larger than SPS. Besides, the hardness of the sintered cemented alloys that was dependent on the grain size and densification could also be improved by SPS and hot pressing.

Preparation of TiB2-TiN and TiN-B Powders and their Processing

2012 ◽  
Vol 527 ◽  
pp. 32-37
Author(s):  
J. Grabis ◽  
Ints Šteins ◽  
Dz. Rašmane
Keyword(s):  
Grain Size ◽  
Relative Density ◽  
Grain Growth ◽  
Spark Plasma Sintering ◽  
Amorphous Boron ◽  
Reactive Sintering ◽  
Plasma Technique ◽  
Sintering Time ◽  
Plasma Sintering ◽  
Spark Plasma

TiN and TiN/TiBSubscript text2 nanoparticles with crystallite size of TiN in the range of 27–38 nm and TiBSubscript text2 in the range of 55–90 nm have been prepared by thermal plasma technique. The prepared nanoparticles and mechanical mixture of TiN with amorphous boron have been densified using spark plasma sintering and the microstructure and density of the samples were compared. The relative density of the samples with content of TiBSubscript text2 about 36 wt.% is in the range of 95.9–97.1% in dependence on the precursors. The higher relative density of the samples provided reactive sintering of TiN/B powder. The grain size of the composites in the range of 0.5–3 µm testified that spark plasma sintering intensified the grain growth in despite of the short sintering time.

Spark Plasma Sintering and Hot Pressing Sintering of Nanocrystalline WC-10CO-0.8VC

2007 ◽  
Vol 534-536 ◽  
pp. 1229-1232
Author(s):  
Li Hui Zhu ◽  
Guang Jie Shao ◽  
Yi Xiong Liu ◽  
Dave Siddle
Keyword(s):  
Relative Density ◽  
Spark Plasma Sintering ◽  
Hot Pressing ◽  
Nanocrystalline Powders ◽  
Microstructure And Properties ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Hot Pressing Sintering

WC-10Co-0.8VC nanocrystalline powders were sintered by spark plasma sintering (SPS) and hot pressing sintering (HPS), and the microstructure and properties were compared. Results show that, sintered at 1300°C, the sample prepared by SPS for only 3 minutes has higher density than that prepared by HPS for 60 minutes. SEM and SPM observation shows SPS at 1200°C has a more uniform and finer microstructure, and most of the WC grains are smaller than 100nm. It has a relative density of 95.1%, HV30 of 1887, and KIC of 11.5 MPam1/2. If a suitable sintering parameter is chosen, SPS is a promising consolidation technique to prepare nanocrystalline WC-10Co-0.8VC with improved properties.

Comparisons of grain size-density trajectory during spark plasma sintering and hot-pressing of zirconia

2008 ◽  
Vol 62 (30) ◽  
pp. 4555-4558 ◽  
Author(s):  
Guillaume Bernard-Granger ◽  
Nathalie Monchalin ◽  
Christian Guizard
Keyword(s):  
Grain Size ◽  
Spark Plasma Sintering ◽  
Hot Pressing ◽  
Plasma Sintering ◽  
Spark Plasma

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.

scholarly journals The Effect of Sintering Temperature on Microstructure and Properties of 94wt% WC - 3wt% TiC - 6wt% Co Sintered by Spark Plasma Sintering

2021 ◽  
Author(s):  
Vahid Aghaali ◽  
Touradj Ebadzadeh ◽  
Seyed Mohammad Zahraee ◽  
Seyed Mohammad Mirkazemi
Keyword(s):  
Fracture Surface ◽  
Tungsten Carbide ◽  
Grain Growth ◽  
Spark Plasma Sintering ◽  
Apparent Density ◽  
Sintering Temperature ◽  
Total Density ◽  
Microstructure And Properties ◽  
Plasma Sintering ◽  
Spark Plasma

Abstract Cemented carbide 94wt% WC − 3wt% TiC − 6wt% Co was sintered by spark plasma sintering at various temperatures of 1200, 1300, and 1400°C and the effect of sintering temperature on the microstructure and properties of this type of hard metals, such as total density, apparent density, hardness, and fracture surface were measured and observed using Field Emission-Scanning Electron Microscopy(FE-SEM), Optical Microscopy (OM), X-ray diffractometry (XRD) and mechanical test instruments. The results showed that the apparent density of the samples increased with increasing sintering temperature from 1200℃ to1300℃ from 13.98 g/cm3 to 14.23 g/cm3, respectively. But in the case of sample sintered at 1400℃, the density was reduced to 14.20 g/cm3. Also, micro-hardness results showed that the hardness of sintered samples increased with the increase of sintering temperature. For the sample sintered at 1200°C the hardness value of 1746.41HV was obtained which increased with increasing sintering temperature from 1300℃ to 1400℃ from 2094.33HV to 2280.97HV, respectively. At the optimum sintering temperature, it was found that TiC inhibited the grain growth of tungsten carbide and increased the hardness values. In addition, as expected, the grain growth of tungsten carbide increased with increasing sintering temperatures. Examination of the fracture surface of sintered samples at different temperatures also showed that brittle fracture involves fracture.

Microstructure and Mechanical Properties of Nanocrystalline FeCr Alloy Prepared by Spark Plasma Sintering

2011 ◽  
Vol 52-54 ◽  
pp. 2197-2202 ◽  
Author(s):  
Darwin Sebayang ◽  
Deni S. Khaerudini ◽  
Hendi Saryanto ◽  
M.A. Othman ◽  
Mat Husin Saleh ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Spark Plasma Sintering ◽  
Hot Pressing ◽  
Sintering Temperature ◽  
Profile Analysis ◽  
Line Profile Analysis ◽  
X Rays ◽  
Diffraction Line Profile ◽  
Plasma Sintering ◽  
Spark Plasma

This paper investigates the efficiency of two consolidation processing techniques prepared by spark plasma sintering (SPS) and hot pressing (HP) which allow obtaining fully dense nanostructured materials. FeCr powders were sintered by using spark plasma sintering (SPS) and hot pressing (HP) sintering techniques over sintering temperature up to 1000oC. The microstructures of the sintered end-products were characterized by Scanning Electron Microscopy (SEM). X-rays diffraction line profile analysis was adopted to analyze the crystallite size of starting and sintered FeCr using Williamson–Hall method. The density of the sintered specimens was measured by using the Archimedes method. The result indicated that the dense specimen with relative similar density and approaching the equilibrium state obtained in shorter time and lower sintering temperature by spark plasma sintering compared to conventional hot pressing. The FeCr specimen prepared by SPS showed more effective to retain nanocrystalline and better mechanical properties than those prepared by HP. The diffraction investigation revealed that the grain growth was not significant in SPS process compared to HP, which would enhance the mechanical properties of the SPS sintered FeCr.

scholarly journals Zirconium Carbide Produced by Spark Plasma Sintering and Hot Pressing: Densification Kinetics, Grain Growth, and Thermal Properties

Materials ◽  
2016 ◽  
Vol 9 (7) ◽  
pp. 577 ◽  
Author(s):  
Xialu Wei ◽  
Christina Back ◽  
Oleg Izhvanov ◽  
Christopher Haines ◽  
Eugene Olevsky
Keyword(s):  
Thermal Properties ◽  
Grain Growth ◽  
Spark Plasma Sintering ◽  
Hot Pressing ◽  
Zirconium Carbide ◽  
Plasma Sintering ◽  
Spark Plasma

Spark plasma sintering and characterization of bulk nanostructured fully stabilized zirconia: Part I. Densification studies

2004 ◽  
Vol 19 (11) ◽  
pp. 3255-3262 ◽  
Author(s):  
U. Anselmi-Tamburini ◽  
J.E. Garay ◽  
Z.A. Munir ◽  
A. Tacca ◽  
F. Maglia ◽  
...  
Keyword(s):  
Crystallite Size ◽  
Heating Rate ◽  
Spark Plasma Sintering ◽  
Significant Influence ◽  
Sintering Temperature ◽  
Stabilized Zirconia ◽  
Sintering Time ◽  
Final Density ◽  
Plasma Sintering ◽  
Spark Plasma

The sintering of nanosize powders of fully stabilized zirconia was investigated using the spark plasma sintering (SPS) method. The influence of sintering temperature, heating rate, direct current pulse pattern, sintering time, and sintering pressure on the final density and grain size of the product was investigated. The dependence of densification on temperature showed a maximum at 1200 °C, resulting with nearly fully dense zirconia with a crystallite size of about 100 nm. Heating rate (50∼300 °C min−1) and sintering time (5–16 min) had no significant influence on the final density and the crystallite size. Pulsing patterns ranging from 2:2 to 48:2 (on:off) had no influence on the density or the crystallite size. However, the applied pressure had a significant influence on the final density but no apparent effect on crystallite size for a sintering temperature of 1200 °C and a hold time of 5 min.

Structure and Properties of Ti55Al45 Alloys Prepared by Mechanical Alloying and Spark Plasma Sintering

2011 ◽  
Vol 308-310 ◽  
pp. 2547-2550
Author(s):  
Yao Dong Liu ◽  
Jing Xing ◽  
Di Ai ◽  
Song Zhe Jin
Keyword(s):  
Grain Size ◽  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Compaction Pressure ◽  
Al Alloy ◽  
Structure And Properties ◽  
Plasma Sintering ◽  
Conventional Sintering ◽  
Spark Plasma ◽  
Short Time

Amorphization and crystallization behaviors of Ti55Al45 powders during mechanical alloys (MA) and subsequent Spark Plasma Sintering are studied. It is found that the nanocrystallization process of the Ti-Al alloy proceeds and the sintering temperature can control the microstructure of alloy. The sintering of the compacts is carried out at the temperatures of 1100—1200°C with a compaction pressure of 30MPa and a heating rate of 30°C min-1. Specimens with high densities and approaching the equilibrium state can be obtained in short time of 180s by spark sintering than conventional sintering. Such shorter high temperature is important to prevent grain growth. The microstructures of the alloy contains equiaxed gamma TiAl with sub-micron grain size and small amount alpha Ti3Al phase.

scholarly journals Influence of Carbon Diffusion and the Presence of Oxygen on the Microstructure of Molybdenum Powders Densified by SPS

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 948
Author(s):  
Mathias Moser ◽  
Sylvain Lorand ◽  
Florian Bussiere ◽  
Frédéric Demoisson ◽  
Hervé Couque ◽  
...  
Keyword(s):  
Grain Growth ◽  
Spark Plasma Sintering ◽  
Inductively Coupled Plasma ◽  
Sintering Temperature ◽  
Carbon Diffusion ◽  
Inductively Coupled ◽  
Molybdenum Carbides ◽  
Plasma Sintering ◽  
Fine Microstructure ◽  
Spark Plasma

Due to molybdenum’s Body-Centered Cubic (BCC) crystalline structure, its ductile–brittle transition temperature is sensitive to shaping, purity and microstructure. Dense molybdenum parts are usually shaped by the powder metallurgy process. The aim of this work concerns the spark plasma sintering of high-purity powders prepared by inductively coupled plasma. The influence of carbon diffusion and its interaction with oxygen on the density (i.e., the densification stage) and on the microstructure (i.e., the grain growth stage) during spark plasma sintering was investigated. The formation of carbide is usually expected for a sintering temperature above 1500 °C leading to grain growth (e.g., more than 10 times larger than the initial powder grain size after sintering at 1900 °C for 10 min). The brittleness was also affected by the segregation of molybdenum carbides at the grain boundaries (i.e., intergranular brittle fracture). Consequently, to reduce the sintering temperature to below 1500 °C, mechanically activated powders were used. From these milled powders, a dense molybdenum disc (60 mm in diameter and 10 mm in thickness) sintered at 1450 °C under a pressure of 70 MPa for 30 min was obtained. It is composed of a fine microstructure without carbide and oxide, its ductility is close to 13% with a maximum resistance of 550 MPa.

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