An insight into pore-network models of high-temperature heat-treated sandstones using computed tomography

2020 ◽  
Vol 77 ◽  
pp. 103227 ◽  
Author(s):  
Bankim Mahanta ◽  
Vikram Vishal ◽  
P.G. Ranjith ◽  
T.N. Singh
Keyword(s):  
Computed Tomography ◽  
High Temperature ◽  
Network Models ◽  
Pore Network ◽  
Heat Treated ◽  
Temperature Heat ◽  
Insight Into

Pyrolysis Characteristic of Nitrogen in Carbon Fibers during High-Temperature Heat Treatment

2015 ◽  
Vol 723 ◽  
pp. 752-756
Author(s):  
Ai Jun Gao ◽  
Zuo Guang Zhang ◽  
Liang Hua Xu
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Carbon Fibers ◽  
Amorphous Region ◽  
Pyrolysis Mechanism ◽  
High Temperature Heat Treatment ◽  
Heat Treated ◽  
Temperature Heat ◽  
Graphite Sheets ◽  
Temperature Heat Treatment

Pyrolysis mechanism of nitrogen in carbon fibers, heat-treated at various temperatures, was investigated, in relation to the nitrogen chemical bonding states. Nitrogen content shows exponential decreasing with increased temperature and extended time. The pyrolysis of nitrogen exhibited time-temperature equivalence. Nitrogen atoms containing hydrogen in the amorphous region and at the edge of microcrystalline, and the double-bonded nitrogen in pyridine rings are easily pyrolyzed, while nitrogen atoms in the six-member ring of the graphite sheets are difficult to be pyrolyzed.

Measurement of Long Range Order in the γ’ Phase of Nickel-Base Superalloys

1969 ◽  
Vol 13 ◽  
pp. 598-608
Author(s):  
J.R. Mihalisin
Keyword(s):  
High Temperature ◽  
Long Range ◽  
Range Order ◽  
Long Range Order ◽  
X Ray Diffraction ◽  
High Temperature Heat Treatment ◽  
Heat Treated ◽  
Temperature Heat ◽  
Long Time ◽  
Nickel Base

The long range order parameter (S) has been measured at room- temperature on the γ’ phase extracted from IN-731 and alloys 713C and 713LC by x-ray diffraction techniques. Measurements were obtained from specimens of IN-731 and alloy 713LC in the as-cast condition and after long time rupture testing. The alloy 713 c specimens were in the as-cast and high temperature heat treated conditions.It was found that long range order in the γ’ phase of IN-731 and alloy 713LC was changed very little after long time rupture testing, and after high temperature heat treatment in the case of alloy 713C.

Mo-W Interdiffusion and the Influence on Potassium Bubbles in W Lamp Wire

1996 ◽  
Vol 458 ◽  
Author(s):  
B. P. Bewlay ◽  
C. L. Briant ◽  
M. L. Murray
Keyword(s):  
High Temperature ◽  
Tungsten Wire ◽  
Heat Treatments ◽  
Diffusion Couples ◽  
Microstructural Changes ◽  
Heat Treated ◽  
Temperature Heat ◽  
Microprobe Data ◽  
Equiaxed Grains

ABSTRACTThe effects of Mo contamination on the microstructure of lamp-grade tungsten wire are investigated in this study. Mo is often used as the mandrel material in the coiling of lamp filaments, and when utilized during high temperature heat treatments significant amounts of Mo can diffuse into the W. In this study, W-Mo diffusion couples were prepared and heat treated at temperatures of 2500°C and above to intentionally contaminate the W with Mo. After dissolution of the Mo and additional high temperature heat treatments of the W, equiaxed grains were observed in the W and excessive porosity was also observed. Explanations for these microstructural changes are discussed. Microprobe data were also obtained to quantify interdiffusion between the W and Mo.

scholarly journals Nanostructural Analyses of Intra- and Intergranular Precipitates in High-temperature Heat-treated Nitrogen-added Austenitic Stainless Steel

2018 ◽  
Vol 58 (8) ◽  
pp. 1459-1466 ◽  
Author(s):  
Minoru Ochi ◽  
Kousei Sato ◽  
Ryo Teranishi ◽  
Yukio Sato ◽  
Jun-ichi Hamada ◽  
...  
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Austenitic Stainless Steel ◽  
Heat Treated ◽  
Temperature Heat

Evolution Mechanism of the Crystallite Geometry in PAN-Based Carbon Fibers during High-Temperature Heat Treatment

2015 ◽  
Vol 1090 ◽  
pp. 26-30
Author(s):  
Ai Jun Gao ◽  
Zuo Guang Zhang ◽  
Liang Hua Xu
Keyword(s):  
Form Factor ◽  
High Temperature ◽  
Carbon Fibers ◽  
Interlayer Space ◽  
Growth Models ◽  
High Temperature Heat Treatment ◽  
Heat Treated ◽  
Temperature Heat ◽  
Increasing Temperature ◽  
Temperature Heat Treatment

The mechanism for the change in the size of the geometry of graphite crystallites in polyacrylonitrile-based carbon fibers heat treated at 1500–2500 °C is proposed. The study indicated that the growth transition temperature of graphite crystallites in carbon fibers is 2000 °C. Above 2000 °C, the interlayer space (d002) decreases slowly and an ordered graphitic structure forms. Below 2000 °C, the variation in the size of the crystallites along the directions of the axis (La‖) and the radius (La⊥) of the carbon fibers that were heat treated at various temperatures was almost the same and the crystallite form factor, La‖/La⊥, which is nearly 1. Above 2000 °C, La‖/La⊥ increases rapidly because the anisotropy of the arrangements of the crystallites in the carbon fibers and the geometry of the crystallites change from being square to becoming rectangular. The crystallite thickness (Lc) also increases with an increasing temperature and below 2000 °C the crystallite form factor (La‖/Lc) increases rapidly. Above 2000 °C, the La‖/Lc stabilized at 3.1. The different growth models in the different directions are the intrinsic root for the variations in the crystallite geometries that underwent high-temperature heat treatments.

A quantitative analysis of a trace amount of hydrogen in high temperature heat-treated carbons

Carbon ◽  
2012 ◽  
Vol 50 (9) ◽  
pp. 3310-3314 ◽  
Author(s):  
Susumu Kashihara ◽  
Shoji Otani ◽  
Hironori Orikasa ◽  
Yasuto Hoshikawa ◽  
Jun-ichi Ozaki ◽  
...  
Keyword(s):  
High Temperature ◽  
Quantitative Analysis ◽  
Trace Amount ◽  
Heat Treated ◽  
Temperature Heat

scholarly journals Nanostructural Analyses of Intra- and Intergranular Precipitates in High-temperature Heat-treated Nitrogen-added Austenitic Stainless Steel

2019 ◽  
Vol 105 (4) ◽  
pp. 418-425
Author(s):  
Minoru Ochi ◽  
Kousei Sato ◽  
Ryo Teranishi ◽  
Yukio Sato ◽  
Jun-ichi Hamada ◽  
...  
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Austenitic Stainless Steel ◽  
Heat Treated ◽  
Temperature Heat

Synthesis of Ti3AlC2 Powder by High Energy Ball Milling and High Temperature Heat Treatment

2010 ◽  
Vol 658 ◽  
pp. 181-184 ◽  
Author(s):  
Jian Feng Zhu ◽  
Guo Quan Qi ◽  
Hai Bo Yang ◽  
Fen Wang
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Phase Evolution ◽  
High Energy ◽  
High Energy Milling ◽  
High Temperature Heat Treatment ◽  
Heat Treated ◽  
Temperature Heat ◽  
Energy Ball ◽  
Temperature Heat Treatment

Highly pure Ti3AlC2 powder was fabricated by combination of high energy milling and heat treatment with Ti, C and Al as starting materials. The details of reactions and phase evolution in fabrication process were investigated. The results shown that the Ti-Al intermetallics, Ti3AlC2 and TiC were formed in high energy milling. The as-milled powders were heat treated subsequently, and the Ti3AlC2 powder with high purity was produced from the reaction among Ti-Al intermetallics, Ti3AlC2 and TiC at relative low temperature (1100 °C).

PM-07Fine Structure Analysis of High Temperature Heat Treated SUSXM15J1 Using FIB-SEM Tomography

Microscopy ◽  
2017 ◽  
Vol 66 (suppl_1) ◽  
pp. i21-i21
Author(s):  
Minoru Ochi ◽  
Ryo Teranishi ◽  
Yukio Sato ◽  
Junichi Hamada ◽  
Chikako Takushima ◽  
...  
Keyword(s):  
High Temperature ◽  
Structure Analysis ◽  
Heat Treated ◽  
Temperature Heat
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