scholarly journals Synthesis of composite AlN-AlON-Al2O3 powders and ceramics prepared by high-pressure sintering

2010 ◽  
Vol 42 (3) ◽  
pp. 283-295 ◽  
Author(s):  
M. Vlasova ◽  
N. Kakazey ◽  
I. Rosales ◽  
L. Krushinskaya ◽  
A. Bykov ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
High Pressure ◽  
Carbothermal Reduction ◽  
Residual Carbon ◽  
Nitrogen Flow ◽  
Graphite Phase ◽  
High Pressure Sintering ◽  
Residual Graphite ◽  
Crystalline Graphite

The process of carbothermal reduction of Al2O3 in a nitrogen flow at temperatures of 1450 and 1600?C has been studied. It was established that the powder synthesized at 1450?C is a mixture of Al2O3 and AlN particles and that the powders synthesized at 1600?C are mixtures of AlN, AlON, and Al2O3. Amorphous and crystalline AlON films form on the surface of Al2O3 and AlN particles. Both synthesized powders contain unreacted residual carbon. In the stage of high-pressure sintering of specimens at a temperature of 1750?C under a pressure of 7 GPa for 110 s, AlON decomposes into AlN and Al2O3. Residual graphite transforms into a crystalline graphite phase, which decreases the strength and increases the fracture toughness. The highest hardness of 19.5 GPa was achieved in the ceramics obtained from the powder synthesized at 1600?C for 4 h, and the largest fracture toughness of ~7.2 MPa?m1/2 was achieved in the ceramics obtained from the powder synthesized at 1450?C for 4h.

Microstructural Study of Diamond Deformed Under High Pressure and Temperature

1985 ◽  
Vol 43 ◽  
pp. 230-231
Author(s):  
E. F. Koch
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Lattice Structure ◽  
Diamond Particle ◽  
Polycrystalline Diamond ◽  
Sintering Process ◽  
Ion Milling ◽  
Sintered Compact ◽  
Transmission Electron ◽  
High Pressure Sintering

Because of the extremely rigid lattice structure of diamond, generating new dislocations or moving existing dislocations in diamond by applying mechanical stress at ambient temperature is very difficult. Analysis of portions of diamonds deformed under bending stress at elevated temperature has shown that diamond deforms plastically under suitable conditions and that its primary slip systems are on the ﹛111﹜ planes. Plastic deformation in diamond is more commonly observed during the high temperature - high pressure sintering process used to make diamond compacts. The pressure and temperature conditions in the sintering presses are sufficiently high that many diamond grains in the sintered compact show deformed microtructures.In this report commercially available polycrystalline diamond discs for rock cutting applications were analyzed to study the deformation substructures in the diamond grains using transmission electron microscopy. An individual diamond particle can be plastically deformed in a high pressure apparatus at high temperature, but it is nearly impossible to prepare such a particle for TEM observation, since any medium in which the diamond is mounted wears away faster than the diamond during ion milling and the diamond is lost.

RMI 6Al-ELI

Alloy Digest ◽  
1988 ◽  
Vol 37 (12) ◽  
Keyword(s):  
Fracture Toughness ◽  
High Pressure ◽  
Room Temperature ◽  
Base Alloy ◽  
Heat Treating ◽  
Age Hardening ◽  
Bend Strength ◽  
Annealed Condition ◽  
Room Temperature Yield Strength ◽  
Alpha Beta

Abstract RMI 6A1-4V ELI is an alpha-beta type of titanium-base alloy that can be strengthened by age hardening. In the mill-annealed condition it has a guaranteed minimum room-temperature yield strength of 120,000 psi and can be increased to as much as 160,000 psi by solution treating and aging. This alloy may be used for high-pressure cryogenic vessels down to 320 F. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and bend strength as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ti-89. Producer or source: RMI Company.

Foam glass obtained through high‐pressure sintering

2018 ◽  
Vol 101 (9) ◽  
pp. 3917-3923 ◽  
Author(s):  
Martin B. Østergaard ◽  
Rasmus R. Petersen ◽  
Jakob König ◽  
Michal Bockowski ◽  
Yuanzheng Yue
Keyword(s):  
High Pressure ◽  
Foam Glass ◽  
High Pressure Sintering

Highly Dense Amorphous Si2 BC3 N Monoliths with Excellent Mechanical Properties Prepared by High Pressure Sintering

2015 ◽  
Vol 98 (12) ◽  
pp. 3782-3787 ◽  
Author(s):  
Bin Liang ◽  
Zhihua Yang ◽  
Jiancun Rao ◽  
Delong Cai ◽  
Xiaoming Duan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
High Pressure Sintering

Enhancement of critical current densities by high-pressure sintering in (Sr,K)Fe2As2PIT wires

2014 ◽  
Vol 27 (9) ◽  
pp. 095002 ◽  
Author(s):  
Sunseng Pyon ◽  
Yuji Tsuchiya ◽  
Hiroshi Inoue ◽  
Hideki Kajitani ◽  
Norikiyo Koizumi ◽  
...  
Keyword(s):  
High Pressure ◽  
Critical Current ◽  
High Pressure Sintering ◽  
Current Densities

scholarly journals Superconducting properties of MgB2 bulk materials prepared by high-pressure sintering

2001 ◽  
Vol 78 (19) ◽  
pp. 2914-2916 ◽  
Author(s):  
Y. Takano ◽  
H. Takeya ◽  
H. Fujii ◽  
H. Kumakura ◽  
T. Hatano ◽  
...  
Keyword(s):  
High Pressure ◽  
Superconducting Properties ◽  
Bulk Materials ◽  
Mgb2 Bulk ◽  
High Pressure Sintering

Synthesis and high-pressure sintering of (W0.5Al0.5)C

2005 ◽  
Vol 40 (4) ◽  
pp. 701-707 ◽  
Author(s):  
Junmin Yan ◽  
Xianfeng Ma ◽  
Wei Zhao ◽  
Huaguo Tang ◽  
Changjun Zhu ◽  
...  
Keyword(s):  
High Pressure ◽  
High Pressure Sintering

scholarly journals Effect of the Strain Rate on the Fracture Behaviour of High Pressure Pre-Charged Samples

Proceedings ◽  
2018 ◽  
Vol 2 (23) ◽  
pp. 1417
Author(s):  
Guillermo Álvarez Díaz ◽  
Tomás Eduardo García Suárez ◽  
Cristina. Rodríguez González ◽  
Francisco Javier Belzunce Varela
Keyword(s):  
Fracture Toughness ◽  
High Pressure ◽  
Hydrogen Embrittlement ◽  
Strain Rate ◽  
Fracture Behaviour ◽  
Structural Steels ◽  
Gaseous Hydrogen ◽  
Displacement Rate ◽  
Steel Strength ◽  
Fracture Tests

The aim of this work is to study the effect of the displacement rate on the hydrogen embrittlement of two different structural steels grades used in energetic applications. With this purpose, samples were pre-charged with gaseous hydrogen at 19.5 MPa and 450 °C for 21 h. Then, fracture tests of the pre-charged specimens were performed, using different displacement rates. It is showed that the lower is the displacement rate and the largest is the steel strength, the strongest is the reduction of the fracture toughness due to the presence of internal hydrogen.

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