Solid-State Reactions of SiC/W-25Re Alloy and Thermal Stability of SiC/Ti/W-25Re Alloy under High-Temperature Annealing

2016 ◽  
Vol 18 (9) ◽  
pp. 1574-1580
Author(s):  
Jun Sae Han ◽  
Seung Sik Jang ◽  
Dong Yong Park ◽  
Yong Jun Oh ◽  
Seong Jin Park
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Solid State ◽  
Solid State Reactions ◽  
High Temperature Annealing ◽  
Thermal Stability Of

Solid state amorphization reactions in deformed Ni-Zr multilayered composites

1990 ◽  
Vol 5 (3) ◽  
pp. 488-497 ◽  
Author(s):  
G. C. Wong ◽  
W. L. Johnson ◽  
E. J. Cotts
Keyword(s):  
Thermal Stability ◽  
Solid State ◽  
Amorphous Phase ◽  
Equilibrium Phase ◽  
Solid State Reactions ◽  
Heat Of Mixing ◽  
Scanning Calorimetry ◽  
Multilayered Composites ◽  
State Amorphization ◽  
Thermal Stability Of

The mechanisms of metallic glass formation and competing crystallization processes in mechanically-deformed Ni-Zr multilayered composites have been investigated by means of differential scanning calorimetry and x-ray diffraction. Our investigation of the heat of formation of amorphous NixZr1−x alloys shows a large negative heat of mixing (on the order of 30 kJ/mole) for compositions near Zr55Ni45 with a compositional dependence qualitatively similar to that predicted by mean field theory. We find that the products of solid state reactions in composites of Ni and Zr can be better understood in terms of the equilibrium phase diagram and the thermal stability of liquid quenched metallic glasses. We have determined the composition of the growing amorphous phase at the Zr interface in these Ni-Zr diffusion couples to be 55 ± 4% Zr. We investigated the kinetics of solid state reactions competing with the solid state amorphization reaction and found the value of the activation energy of the initial crystallization and growth of the growing amorphous phase to be 2.0 ± 0.1 eV, establishing an upper limit on the thermal stability of the growing amorphous phase.

Crystallization Characteristics and Thermal Stability of Fluor-Hydroxyapatite Composites with Zirconia

2012 ◽  
Vol 182-183 ◽  
pp. 122-125
Author(s):  
Li Li Wang ◽  
Xiu Feng Wang ◽  
Cheng Long Yu ◽  
Hong Tao Jiang
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Solid State ◽  
Low Temperature ◽  
Solid Solutions ◽  
Tricalcium Phosphate ◽  
Solid State Reaction ◽  
Calcium Fluoride ◽  
Raw Materials ◽  
Thermal Stability Of

Hydroxyapatite (HA) was synthesized in presence of 20wt% m-ZrO2by solid state reaction between tricalcium phosphate(TCP) and Ca(OH)2at 1000 °C for 2h. Similarily, Fluorine hydroxyapatite(FA) was synthesized using tricalcium phosphate and calcium fluoride as raw materials at 1000 °Cfor 3h. The as-prepared HA was mixed with 10%,25%,45%,55%,70wt% FA and the mixture was sintered at 1000°C-1400°C for 2h. The main phase and bulk density was measured. The results show that when the relative amount of FA to HA increased, the decomposition of the composite is decreased gradually because of the formation of thermally stable FHA solid solutions. Low temperature would effect the exchange of ionic between FA and HA,while high temperature would impact synthesis of composites, because high temperature would lead to dissolution of HA ,which has to react with FA. Increase the content of HA would be advantage for synthesis FHA-ZrO2composite.

Effect of the Crystallographic Orientation of Underlying Poly-Si on the Thermal Stability of the TiSi2 Film

1992 ◽  
Vol 280 ◽  
Author(s):  
Y. W. Kim ◽  
I. K. Kim ◽  
N. I. Lee ◽  
J. W. Ko ◽  
S. T. Ahn ◽  
...  
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Solid State ◽  
Surface Energy ◽  
Microstructural Evolution ◽  
Solid State Reaction ◽  
Crystallographic Orientation ◽  
Amorphous Si ◽  
Si Films ◽  
Thermal Stability Of

ABSTRACTThe effect of the crystallographic orientation of underlying poly-Si film on the thermal stability of the TiSi2 film was studied. Different preferred orientations of the poly-Si film were obtained by annealing poly-Si or amorphous Si films at various temperatures. The TiSi2 film was formed by the solid-state reaction of the Ti film sputtered on the poly-Si film. The thermal stability of the TiSi2 film was evaluated by changes in the sheet resistance and microstructural evolution during furnace anneals. The TiSi2 film on poly-Si with the <110> preferred orientation shows more stable conductivity during high temperature anneals than with the <111> orientation. The surface energy of underlying poly-Si is expected to influence the thermal stability of the TiSi2/poly-Si structure significantly. Better thermal stability of the TiSi2 film can be obtained by the higher surface energy of underlying poly-Si.

Thermal Stability of LixCoO2 Electrodes for All-Solid-State Secondary Batteries Operating at High-Temperature

2020 ◽  
Vol MA2020-01 (2) ◽  
pp. 423-423
Author(s):  
Quentin Denoyelle ◽  
Lydie Bourgeois ◽  
Yann Tison ◽  
Hervé Martinez ◽  
Dany Carlier ◽  
...  
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Solid State ◽  
Thermal Stability Of

scholarly journals Comprehensive microstructural and optical characterization of the thermal stability of aluminum-titanium oxynitride thin films after high temperature annealing in air

2021 ◽  
Author(s):  
R. Escobar-Galindo ◽  
I. Heras ◽  
E. Guillén ◽  
F. Munnik ◽  
I. Azkona ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Stability ◽  
High Temperature ◽  
Dielectric Behavior ◽  
Vacuum Arc ◽  
Surface Oxide Layer ◽  
High Temperature Annealing ◽  
Elastic Recoil ◽  
Thermal Stability Of

AbstractThe thermal stability of two AlyTi1-y(OxN1-x) layers prepared by cathodic vacuum arc deposition with different oxygen content was studied after high temperature annealing of the samples in air. These layers were designed to be part of solar-selective coating (SSC) stacks. Compositional and microstructural characterization of the thin films was performed before and after the thermal treatment by elastic recoil detection (ERD), transmission electron microscopy, and Raman spectroscopy. AlyTi1-yN sample was stable after 2 h of annealing at 450 °C. Initial stages of the formation of a surface oxide layer after annealing at 650 °C were observed both by ERD and Raman analysis. Contrarily, no changes were found after 2 h annealing treatment either at 450 and 650 °C in the composition and microstructure of AlyTi1-y(OxN1-x) sample. In both samples, the formation of a surface anatase TiO2 film was reported after 2 h annealing at 800 °C. These compositional and microstructural changes were correlated with the optical properties determined by spectroscopic ellipsometry. A transition from metallic to dielectric behavior with increasing annealing temperature was observed. These results complete the durability studies on the designed SSC based on AlyTi1-y(OxN1-x) materials, confirming that these stacks withstand breakdown at 600 °C in air.

Study of Grain Growth Kinetics in Submicrocrystalline Armco-Iron

2007 ◽  
Vol 550 ◽  
pp. 465-470 ◽  
Author(s):  
A.N. Aleshin ◽  
Alex M. Arsenkin ◽  
Sergey V. Dobatkin
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Low Temperature ◽  
Grain Growth ◽  
Growth Kinetics ◽  
Armco Iron ◽  
High Temperature Annealing ◽  
Grain Growth Kinetics ◽  
Submicrocrystalline Materials ◽  
Thermal Stability Of

The paper is devoted to the problem of thermal stability of ultra-fine grained (submicrocrystalline) materials prepared by severe plastic deformation. A basis of the paper lies in a fact that there is practically no grain growth in submicrocrystalline materials when annealing temperature is less than 0.35Tm. Reasons of high thermal stability of submicrocrystalline materials at low temperatures are widely discussed in literature. One of them is the affect of triple junction drag on grain boundaries motion. During annealing at a low temperature triple junction drag controls microstructure evolution in submicrocrystalline materials, and this phenomenon can be used to improve their thermal stability at high temperatures. The aim of this paper is to investigate grain growth kinetics in a two-step regime, low temperature and high temperature annealing. The experiments on grain growth were performed in submicrocrystalline Armco-iron fabricated by high pressure torsion. It is established that long-time low temperature pre-annealing reduces the grain growth rate in following high temperature annealing by a factor greater than two.

Stable Ohmic Contacts on GaAs and GaN Devices for High Temperatures

2002 ◽  
Vol 743 ◽  
Author(s):  
A. Piotrowska ◽  
E. Kaminska ◽  
A. Barcz ◽  
K. Golaszewska ◽  
H. Wrzesinska ◽  
...  
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
High Temperatures ◽  
Ohmic Contacts ◽  
High Temperature Annealing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermal Stability Of

ABSTRACTWe have studied thermal stability of Nb and NbN contacts to GaAs and GaN by x-ray diffraction and SIMS, and demonstrated their excellent behaviour under high temperature annealing. GaAs/Nb and GaAs/NbN contacts are stable up to 800°C and 900°C, respectively while GaN/NbN and GaN/Nb/NbN remain stable up to 1000°C.

Study on the Morphology and Thermal Stability of Li2SrSiO4: Tb3+ Materials

2014 ◽  
Vol 989-994 ◽  
pp. 437-440 ◽  
Author(s):  
Pan Li You
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Solid State ◽  
White Light ◽  
Solid State Reaction ◽  
Emission Intensity ◽  
Room Temperature ◽  
Light Emitting ◽  
White Light Emitting Diodes ◽  
Thermal Stability Of

A series of Tb3+-doped Li2SrSiO4:Tb3+phosphors were prepared by high temperature solid state reaction. The morphology and the thermal stability of Li2SrSiO4:Tb3+phosphors were discussed by SEM and PL measurements, respectively. The results showed that the morphology of Li2SrSiO4:Tb3+was changed from flower-like to rod-like with increasing Tb3+-doped content. Moreover, the emission intensity measured at 3500C almost maintain with constant compared with that measured at room temperature. The results showed that Li2SrSiO4:Tb3+phosphor might be a potential phosphor for white light-emitting diodes.

The Ordered Phase Formation in Ti-Al-Ga Alloys

1970 ◽  
Vol 28 ◽  
pp. 440-441
Author(s):  
Shiro Fujishiro ◽  
Harold L. Gegel
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Titanium Alloys ◽  
Growth Kinetics ◽  
Stoichiometric Composition ◽  
Good Potential ◽  
Alpha Titanium ◽  
Cold Rolled ◽  
Kinetics Of ◽  
Thermal Stability Of

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization

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