scholarly journals Sintering Process and Its Mechanism of MgB2 Superconductors

10.5772/33794 ◽  
2012 ◽  
Author(s):  
Zongqing Ma ◽  
Yongchang Liu
Keyword(s):  
Sintering Process ◽  
Mgb2 Superconductors

Study on the Carbon Doping of Sugar Added MgB2 Superconductors Prepared by Low Temperature Sintering

2014 ◽  
Vol 998-999 ◽  
pp. 91-94
Author(s):  
Rui Wang ◽  
Zong Qing Ma ◽  
Hui Yang
Keyword(s):  
Low Temperature ◽  
Elemental Carbon ◽  
Decomposition Reaction ◽  
Chemical Activity ◽  
Carbon Doping ◽  
Low Temperature Sintering ◽  
Sintering Process ◽  
Carbon Doped ◽  
Sintering Condition ◽  
Mgb2 Superconductors

With sugar as an addition, the active carbon released from sugar can lead to the effective carbon doping in MgB2 superconductors only under the condition of high temperature sintering. However, this kind of carbon doping cannot occur at low temperature sintering condition. The reason is that the carbon released from the decomposition reaction of the sugar added in MgB2 has very low chemical activity during low temperature sintering process, which is similar with the results of elemental carbon or graphite doping directly. Thus, only the sintering temperature reaches a certain temperature or more (generally greater than 700oC), the carbon can possess sufficiently high chemical activity and go into the lattice of MgB2 to replace the B. In the condition of low temperature, it is difficult to form an effective carbon-doped.

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.

Fabrication and Mechanical Properties of ultra fine WC-6wt.%Co by Spark Plasma Sintering Process

2011 ◽  
Vol 49 (01) ◽  
pp. 40-45 ◽  
Author(s):  
Hyun-Kuk Park ◽  
Seung-Min Lee ◽  
Hee-Jun Youn ◽  
Ki-Sang Bang ◽  
Ik-Hyun Oh
Keyword(s):  
Mechanical Properties ◽  
Spark Plasma Sintering ◽  
Sintering Process ◽  
Plasma Sintering ◽  
Spark Plasma
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