scholarly journals High-temperature structure of Co3O4 : Understanding spinel inversion using in situ and ex situ measurements

2019 ◽  
Vol 99 (10) ◽  
Author(s):  
Taylor D. Sparks ◽  
Aleksander Gurlo ◽  
Maged F. Bekheet ◽  
Michael W. Gaultois ◽  
Gennady Cherkashinin ◽  
...  
Keyword(s):  
High Temperature ◽  
Ex Situ ◽  
Temperature Structure ◽  
High Temperature Structure

Improving Convergence of Replica-Exchange Simulations through Coupling to a High-Temperature Structure Reservoir

2007 ◽  
Vol 3 (2) ◽  
pp. 557-568 ◽  
Author(s):  
Asim Okur ◽  
Daniel R. Roe ◽  
Guanglei Cui ◽  
Viktor Hornak ◽  
Carlos Simmerling
Keyword(s):  
High Temperature ◽  
Replica Exchange ◽  
Temperature Structure ◽  
High Temperature Structure

High Temperature Structure Stability Study on Nb-Containing Nickel-Base Superalloys

2007 ◽  
Vol 546-549 ◽  
pp. 1281-1288 ◽  
Author(s):  
Xi Shan Xie ◽  
Jian Xin Dong ◽  
Mai Cang Zhang ◽  
Shu Hong Fu
Keyword(s):  
High Temperature ◽  
Phase Formation ◽  
Inconel 718 ◽  
Phase Changes ◽  
Stable Phase ◽  
Structure Stability ◽  
Temperature Structure ◽  
Alloy 718 ◽  
Strengthening Phases ◽  
High Temperature Structure

High temperature structure stability of 2 important Nb-containing Ni-base superalloys Inconel 718 (Ni-19Cr-18Fe-3Mo-5Nb-1Ti-0.5Al) and Inconel 740 (Ni-25Cr-20Co-0.5Mo-2Nb -1.8Ti-0.8Al) have been studied on the relationship of microstructure to mechanical properties via SEM, TEM, SAD, XRD and quantitative determination of precipitated phases by micro-chemical analysis. The longest exposure times are 50,000hrs at 650°C for Alloy 718 and 4,000hrs at 704°C, 725°C and 760°C for Alloy 740. The structure instabilities for these 2 Alloys are: 1) strengthening phases γ″/γ′ coarsening; 2) meta-stable strengthening phases change to stable phase, such as γ″→ δ-Ni3Nb for Alloy 718 and γ′→ η-Ni3Ti for Alloy 740; 3) embrittling phases formation, such as α-Cr and σ-phase formation in Alloy 718 and high Si-containing G-phase formation in Alloy 740. On the base of understanding phase changes at high temperature exposures the structure stability of Inconel 718 and Inconel 740 has been improved both by minor adjustment of alloys chemistry. The modifications of Alloy 718 and Alloy 740 are to be developed in the near future.

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