Nickel-graphite composites of variable architecture by graphitization-accompanied spark plasma sintering and hot pressing and their response to phase separation

We report the formation and phase separation response of nickel-graphite composites with variable-architecture phases by graphitization-accompanied consolidation via Spark Plasma Sintering and hot pressing. It was shown that the application of pressure during consolidation is crucial for the occurrence of graphitization and formation of 3D graphite structures. We evaluated the suitability of the synthesized composites as precursors for making porous structures. Nickel behaved as a space holder with the particle size and spatial distribution changing during consolidation with the temperature and determining the structure of porous graphite formed by phase separation by dissolution in HCl. The response of the consolidated Ni-Cgr to separation of carbon by its burnout in air was studied. The result of the carbon removal was either the formation of a dense and continuous NiO film on the surface of the compacts or oxidation through the compact thickness. The choice between these two options depended on the density of the compacts and on the presence of carbon dissolved in nickel. It was found that during the burnout of graphite from Ni-Cgr composites, sintering, rather than formation of pores, dominated.

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A Novel Approach to Prepare Ni-Coated TiB2 Cermet

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.336-338.1517 ◽

2007 ◽

Vol 336-338 ◽

pp. 1517-1520 ◽

Cited By ~ 1

Author(s):

Zhou Fang ◽

Zheng Yi Fu ◽

Hao Wang ◽

Wei Min Wang ◽

Qing Jie Zhang

Keyword(s):

Mechanical Properties ◽

Particle Size ◽

Spark Plasma Sintering ◽

Hot Pressing ◽

Plasma Sintering ◽

Novel Approach ◽

Ni Powder ◽

Spark Plasma ◽

Mean Size ◽

Tib2 Particles

A novel approach was developed to prepare Ni-coated TiB2 cermet. Fine Ni particles with mean particle size of about 80 nm were impacted onto coarse TiB2 particles having a mean size of about 5 μm to form Ni-coated TiB2 powder by Hybridization. The conventional blended TiB2-Ni powder, as well as Ni-coated TiB2 powder, was sintered by hot pressing (HP) method and Spark Plasma Sintering (SPS) method. Compared with the conventional blended TiB2-Ni cermet, particle features and mechanical properties of the Ni-coated TiB2 cermet were investigated. The microstructure analysis reveals that the thickness of Ni film is around 4 nm. It is concluded that the mechanical properties of Ni-coated TiB2 cermet are superior to the blended TiB2-Ni cermet.

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Spark plasma sintering and hot pressing of ZrB2–MoSi2 ultra-high-temperature ceramics

Materials Science and Engineering A ◽

10.1016/j.msea.2007.01.164 ◽

2008 ◽

Vol 475 (1-2) ◽

pp. 108-112 ◽

Cited By ~ 63

Author(s):

Andrea Balbo ◽

Diletta Sciti

Keyword(s):

High Temperature ◽

Spark Plasma Sintering ◽

Hot Pressing ◽

Ultra High Temperature Ceramics ◽

Plasma Sintering ◽

Spark Plasma ◽

Ultra High Temperature

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Effect of initial particle size and various composition on the spark plasma sintering of binderless tungsten carbide

Journal of Physics Conference Series ◽

10.1088/1742-6596/1758/1/012022 ◽

2021 ◽

Vol 1758 (1) ◽

pp. 012022

Author(s):

E A Lantsev ◽

N V Malekhonova ◽

V N Chuvil`deev ◽

A V Nokhrin ◽

M S Boldin ◽

...

Keyword(s):

Particle Size ◽

Tungsten Carbide ◽

Spark Plasma Sintering ◽

Initial Particle ◽

Initial Particle Size ◽

Plasma Sintering ◽

Spark Plasma

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.534-536.1229 ◽

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.

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Microstructure and Magnetic Properties of Hot-Pressed and Hot-Deformed Composite Magnets Produced by Spark Plasma Sintering Method

Materials Science Forum ◽

10.4028/www.scientific.net/msf.686.740 ◽

2011 ◽

Vol 686 ◽

pp. 740-744 ◽

Cited By ~ 1

Author(s):

Yi Long Ma ◽

Deng Ming Chen ◽

Qian Shen ◽

Peng Jun Cao

Keyword(s):

Magnetic Properties ◽

Spark Plasma Sintering ◽

Hot Pressing ◽

Magnetic Energy ◽

Pressing Temperature ◽

Energy Product ◽

Plasma Sintering ◽

Spark Plasma ◽

Energy Products ◽

Fe Addition

Bulk isotropic and anisotropic Nd13.5Fe80.4Ga0.5B5.6 and Nd13.5Fe80.4Ga0.5B5.6/Fe magnets were synthesized by applying spark plasma sintering (SPS) technique. The effect of hot-pressing temperature on the magnetic properties of hot-pressed (HP) and hot-deformed (HD) magnets without additive and with 5% Fe addition was investigated. With increasing sintering temperature for HP magnets, the grain grew gradually. For HD magnets, the optimal magnetic properties could be obtained at hot-pressing temperature 680°C due to the development of desired c-axis texture and uniform microstructure, which resulted from the appropriate and uniform grain size in HP magnets. Fe addition could enhance remanence (Br) and magnetic energy products ((BH)m) of HP and HD magnets. However, the maximum magnetic energy product of HD magnets decreased when hot-pressing temperature was higher than 650°C.

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