scholarly journals Structural transformations of a gas-atomized Al62.5Cu25Fe12.5 alloy during detonation spraying, spark plasma sintering and hot pressing

2021 ◽  
Vol 53 (3) ◽  
pp. 379-386
Author(s):  
Igor Batraev ◽  
Witor Wolf ◽  
Boris Bokhonov ◽  
Arina Ukhina ◽  
Ivanna Kuchumova ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Hot Pressing ◽  
Single Phase ◽  
Complex Structure ◽  
Icosahedral Phase ◽  
Structural Transformations ◽  
Detonation Spraying ◽  
Complete Melting ◽  
Plasma Sintering ◽  
Spark Plasma

In this work, we traced structural transformations of an Al62.5Cu25Fe12.5 alloy, in which a quasicrystalline icosahedral phase (i-phase) can be formed, upon spraying onto a substrate and consolidation from the powder into the bulk state. The Al62.5Cu25Fe12.5 powder was obtained by gas atomization and consisted of i-phase and ?-phase AlCu(Fe). The powder was detonation sprayed (DS) and consolidated by spark plasma sintering (SPS)/hot pressing (HP). During DS, the particles experienced partial or complete melting and rapid solidification, which resulted in the formation of coatings of a complex structure. The composite regions containing i-phase were inherited from the powder alloy. The fraction of the material that experienced melting solidified as ?-phase AlFe(Cu) in the coating. It was suggested that the difficulty of obtaining i-phase upon post-spray annealing is related to aluminum depletion of the alloy during DS. During SPS and HP, the elemental composition of the alloy was preserved, while the exposure to an elevated temperature led to phase homogenization. SPS and HP conducted at 700?C resulted in full densification and the formation of a single-phase quasicrystalline alloy. The sintered single-phase alloy showed a higher microhardness in comparison with the DS coatings.

scholarly journals Thermoelectric properties of Cu3SbSe3 with intrinsically ultralow lattice thermal conductivity

2014 ◽  
Vol 2 (38) ◽  
pp. 15829-15835 ◽  
Author(s):  
Kriti Tyagi ◽  
Bhasker Gahtori ◽  
Sivaiah Bathula ◽  
A. K. Srivastava ◽  
A. K. Shukla ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Solid State ◽  
Spark Plasma Sintering ◽  
Thermoelectric Properties ◽  
Solid State Reaction ◽  
Electrical Transport ◽  
Single Phase ◽  
Lattice Thermal Conductivity ◽  
Plasma Sintering ◽  
Spark Plasma

Intrinsically ultra-low thermal conductivity and electrical transport in single-phase Cu2SbSe3 synthesized employing a solid state reaction and spark plasma sintering.

Transparent mullite ceramic from single-phase gel by Spark Plasma Sintering

2009 ◽  
Vol 29 (13) ◽  
pp. 2705-2711 ◽  
Author(s):  
Guimin Zhang ◽  
Yucheng Wang ◽  
Zhengyi Fu ◽  
Hao Wang ◽  
Weiming Wang ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Single Phase ◽  
Mullite Ceramic ◽  
Plasma Sintering ◽  
Spark Plasma

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.

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

2011 ◽  
Vol 686 ◽  
pp. 740-744 ◽  
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.

Nonstoichiometric Composition and Densification of CaRuO3 by SPS

2007 ◽  
Vol 352 ◽  
pp. 251-254 ◽  
Author(s):  
Nittaya Keawprak ◽  
Rong Tu ◽  
Takashi Goto
Keyword(s):  
Spark Plasma Sintering ◽  
Single Phase ◽  
Lattice Parameters ◽  
Second Phase ◽  
Nonstoichiometric Composition ◽  
Plasma Sintering ◽  
Spark Plasma

Calcium ruthenates were prepared in different ratios of Ru to Ca (RRu/Ca = 0.5～1.4) by spark plasma sintering. CaRuO3 in a single phase was obtained at RRu/Ca = 1.0. At RRu/Ca < 1.0, a mixture of CaRuO3 and CaO was obtained, whereas CaRuO3 with second phase of RuO2 was obtained at RRu/Ca > 1.0. The density at RRu/Ca < 1.0 were 80-85% and slightly increased with increasing RRu/Ca. The density significantly increased up to 95% with increasing RRu/Ca from 1.1 to 1.4, suggesting that the second phase of RuO2 was effective to densify CaRuO3. The density of CaRuO3 in a single phase was 82% at most. The lattice parameters of CaRuO3 decreased with increasing RRu/Ca from 0.7 to 1.0, showing a nonstoichiometric range of Ca1+δRuO3+δ.

Formation of in-situ reinforced microstructure in α–sialon ceramics I: Stoichiometric oxygen-rich compositions

2002 ◽  
Vol 17 (2) ◽  
pp. 336-342 ◽  
Author(s):  
Zhijian Shen ◽  
Hong Peng ◽  
Mats Nygren
Keyword(s):  
Hot Pressing ◽  
Single Phase ◽  
Transient Liquid Phase ◽  
Precursor Powder ◽  
Temperature Dependent ◽  
Consolidation Process ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Equiaxed Grains

The abnormal grain growth in α–sialon ceramics was investigated. The preparations had stoichiometric compositions on the oxygen-rich phase boundary, and they were stabilized by Y, Nd, Sm, Dy, and Yb, respectively. Specimens were prepared from α–Si3N4 as precursor powder by applying conventional hot pressing and a novel rapid consolidation process, namely spark plasma sintering (SPS). Single-phase α–sialon ceramics with in situ reinforced bimodal microstructure, i.e., large elongated grains embedded in a matrix consisting of small equiaxed grains, were obtained above 1750 °C in all systems compacted by SPS and above 1800 °C in systems stabilized by Nd and Sm but not Dy, Y, or Yb by a two-step hot-pressing procedure. It was observed that the formation of abnormally grown α–sialon grains was strongly temperature-dependent, indicating that it was encouraged by the formation of a transient liquid phase that stimulated the dissolution of any remaining nitride precursors and early formed small α–sialon grains and sequentially facilitated supersaturation by the α–sialon constituents. The presence of elongated grains improves fracture resistance in the obtained materials.

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