Thermal Stability Of Electrodeposited Nanocrystalline Ni-45%Fe Alloys

1996 ◽  
Vol 451 ◽  
Author(s):  
F. Czerwinski ◽  
H. Li ◽  
F. Megret ◽  
J. A. Szpunar ◽  
D. G. Clark ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Grain Size ◽  
Phase Composition ◽  
Growth Kinetics ◽  
Annealing Temperature ◽  
Inert Atmosphere ◽  
Time Periods ◽  
Fe Alloys ◽  
20 Nm ◽  
Thermal Stability Of

ABSTRACTElectrolytically deposited nanocrystalline Ni-45%Fe alloys, composed of γ (f.c.c.) phase, were annealed at 573 and 673 K for time periods up to 20 h in an inert atmosphere of argon. The evolutions of crystallographic texture, grain size, and microhardness were analyzed as a function of annealing parameters. The initial grains, approximately 5 nm in size increased after annealing up to 10–20 nm, however, the growth kinetics and the final grain size depended on the temperature. A correlation was found between the grain size and alloy microhardness. The phase composition was unstable and during annealing the α(b.c.c) phase was detected to precipitate from the γ matrix. The texture of γ phase, consisted of two fibre components of <111> and <200>, and evolved at high temperatures. Although the detailed changes depended on the annealing temperature, in general, the <111> component became stronger at the expense of the <200> component.

Thermal Stability of Ultrafine-Grained Pure Titanium Processed by High-Pressure Torsion

2021 ◽  
Vol 1016 ◽  
pp. 338-344
Author(s):  
Wan Ji Chen ◽  
Jie Xu ◽  
De Tong Liu ◽  
De Bin Shan ◽  
Bin Guo ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermal Stability ◽  
Grain Size ◽  
High Pressure ◽  
Annealing Temperature ◽  
High Pressure Torsion ◽  
Stored Energy ◽  
Ultrafine Grained ◽  
Average Grain Size ◽  
Thermal Stability Of

High-pressure torsion (HPT) was conducted under 6.0 GPa on commercial purity titanium up to 10 turns. An ultrafine-grained (UFG) pure Ti with an average grain size of ~96 nm was obtained. The thermal properties of these samples were studied by using differential scanning calorimeter (DSC) which allowed the quantitative determination of the evolution of stored energy, the recrystallization temperatures, the activation energy involved in the recrystallization of the material and the evolution of the recrystallized fraction with temperature. The results show that the stored energy increases, beyond which the stored energy seems to level off to a saturated value with increase of HPT up to 5 turns. An average activation energy of about 101 kJ/mol for the recrystallization of 5 turns samples was determined. Also, the thermal stability of the grains of the 5 turns samples with subsequent heat treatments were investigated by microstructural analysis and Vickers microhardness measurements. It is shown that the average grain size remains below 246 nm when the annealing temperature is below 500 °C, and the size of the grains increases significantly for samples at the annealing temperature of 600 °C.

Thermal Stability of Nanocrystalline Grain Size in Ternary Fe-Base Alloys

2013 ◽  
Vol 753 ◽  
pp. 341-344 ◽  
Author(s):  
Carl C. Koch ◽  
Ronald O. Scattergood ◽  
Hasan Kotan ◽  
Mostafa Saber
Keyword(s):  
Thermal Stability ◽  
Grain Size ◽  
Annealing Temperature ◽  
Thermal Stabilization ◽  
Relative Importance ◽  
Ni Alloys ◽  
Thermodynamic Stabilization ◽  
Temperature Ranges ◽  
Ternary Additions ◽  
Thermal Stability Of

We report recent research in our laboratory on the thermal stabilization of nanocrystalline binary alloys with ternary additions. Fe-Cr and Fe-Ni alloys with the ternary addition of Zr are studied. The thermal stability of these nanocrystalline alloys, prepared by mechanical alloying of powders, is studied by XRD, TEM and hardness as a function of annealing temperature. The relative importance of thermodynamic or kinetic stabilization in various temperature ranges is discussed for the different alloys. In agreement with our recent model for thermodynamic stabilization, it is found that Zr solute additions are more effective in stabilizing the nanocrystalline grain size in the Fe-Cr than in the Fe-Ni system.

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

Grain Growth in Nanocrystalline Nickel

1999 ◽  
Vol 580 ◽  
Author(s):  
G.D. Hibbard ◽  
U. Erb ◽  
K.T. Aust ◽  
G. Palumbo
Keyword(s):  
Thermal Stability ◽  
Grain Size ◽  
Grain Growth ◽  
Size Distributions ◽  
Nanocrystalline Nickel ◽  
Scanning Calorimetry ◽  
Solute Content ◽  
Grain Size Distributions ◽  
Thermal Stability Of ◽  
Total Solute Content

AbstractIn this study, the effect of grain size distribution on the thermal stability of electrodeposited nanocrystalline nickel was investigated by pre-annealing material such that a limited amount of abnormal grain growth was introduced. This work was done in an effort to understand the previously reported, unexpected effect, of increasing thermal stability with decreasing grain size seen in some nanocrystalline systems. Pre-annealing produced a range of grain size distributions in materials with relatively unchanged crystallographic texture and total solute content. Subsequent thermal analysis of the pre-annealed samples by differential scanning calorimetry showed that the activation energy of further grain growth was unchanged from the as-deposited nanocrystalline nickel.

Toxic properties of Aeromonas proteolytica

1974 ◽  
Vol 20 (10) ◽  
pp. 1403-1409 ◽  
Author(s):  
B. G. Foster ◽  
Mary O. Hanna
Keyword(s):  
Thermal Stability ◽  
Culture Filtrate ◽  
Hemolytic Activity ◽  
Optimal Growth ◽  
Growth Conditions ◽  
The Other ◽  
Activity Peak ◽  
Endopeptidase Activity ◽  
Time Periods ◽  
Thermal Stability Of

Aeromonas proteolytica was grown for various time periods in nutrient broth, tryptic soy broth, a semisynthetic medium, and 1 and 5% peptone under different conditions involving temperature and in continuous shake and stationary flasks. The cell-free culture filtrates were tested for hemolytic, endopeptidase, and dermonecrotic activity and optimal growth conditions for their production were determined. The dermonecrotic activity and endopeptidase activity was found to be parallel in all tests, while hemolysin was independent of the other two. Studies on the thermal stability of the culture filtrate revealed that hemolysin and dermonecrotic and endopeptidase activity were destroyed at 70 °C for 30 min. Fractionation of the filtrate by Sephadex G-200 resolved three peaks at 280 nm. Peak I was inactive; peak II contained endopeptidase and dermonecrotic and hemolytic activity; peak III contained pigment and hemolysin. Evidence is presented that the endopeptidase and dermonecrotic substance found in the cell-free filtrates of A. proteolytica grown medium appear at the same time and thus may be the same entity.

scholarly journals Effects of Current on Arc Fabrication of Cu Nanoparticles

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
M. Z. Kassaee ◽  
F. Buazar ◽  
E. Motamedi
Keyword(s):  
Thermal Stability ◽  
Distilled Water ◽  
Face Centered Cubic ◽  
Cu Nanoparticles ◽  
Dta Analysis ◽  
Face Centered ◽  
Average Size ◽  
20 Nm ◽  
Thermal Stability Of ◽  
Sem Analyses

Arc-fabricated copper nanoparticles (Cu Nps) size, morphology and the crystalline structure, as well as the yields of Nps appear sensitive to the applied currents (50–160 A) in distilled water. The results indicate that the sizes of Cu Nps are directly proportional to the currents employed. At 50 A, TEM, XRD, and SEM analyses show fabrication of relatively purest, the most dispersed, face-centered cubic (fcc) brown Cu Nps with rather smallest average size of 20 nm. At the same current, the TGA-DTA analysis reveals neither weight loss nor gain, indicating thermal stability of the fabricated Cu Nps.

The Mechanical Characteristics of Straw/poly(Lactic Acid) Composite Materials

2011 ◽  
Vol 335-336 ◽  
pp. 153-156
Author(s):  
Xue Li Wu ◽  
Jian Hui Qiu ◽  
Lin Lei ◽  
Yang Zhao ◽  
Eiichi Sakai
Keyword(s):  
Thermal Stability ◽  
Grain Size ◽  
Lactic Acid ◽  
Mechanical Characteristics ◽  
Fracture Strain ◽  
Filler Content ◽  
Agricultural Wastes ◽  
Poly Lactic Acid ◽  
Effective Utilization ◽  
Thermal Stability Of

To consider the effective utilization of plastics and agricultural wastes, rice straw fibre was extracted from agricultural wastes, and then composited with polylactic acid(PLA). The thermal stability of straw/poly(lactic acid)(straw/PLA) composites decreased (Thermogravimetric Analysis, TGA). Tensile strength, fracture strain and sharply impact strength of straw/PLA were decreased with the increase of filler content and grain size of straw. Yong’s modulus were increased as the increasing of straw content.

scholarly journals Nitridated Ca2NaMg2V3O12: Eu3+ Vanadate Garnet Phosphor-in-Glass

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2996
Author(s):  
Damian Pasinski ◽  
Jerzy Sokolnicki
Keyword(s):  
Thermal Stability ◽  
Single Phase ◽  
Low Energy ◽  
Color Temperature ◽  
Garnet Structure ◽  
Air Atmosphere ◽  
Ammonia Atmosphere ◽  
20 Nm ◽  
Thermal Stability Of ◽  
Emission Quantum Yield

In this study, Ca2NaMg2V3O12 coordination compound undoped and doped with Eu3+ obtained in the air and ammonia atmosphere by solid-state reaction was investigated. Ca2NaMg2V3O12: Eu3+ obtained in the ammonia atmosphere was then investigated as a phosphor-in-glass (PiG). Annealed Ca2NaMg2V3O12: Eu3+ phosphor forms a single phase with the cubic garnet structure and Ia3d space group. Nitridation in ammonia causes a widening of a VO43− group emission band on the low energy side and it red-shifts by 20 nm. The emission of Eu3+ is extended as compared to the non-nitridated phosphor. Ca2NaMg2V3O12: Eu3+ after nitridation shows higher emission quantum yield (QY): 49 vs. 45 and lower correlated color temperature (CCT) and 4179 vs. 4998 as compared to phosphor without nitridation. The QY for PiG is 55. The thermal stability of nitridated phosphors is superior to phosphor obtained in the air atmosphere and is further enhanced for PiG.

Effect of annealing temperature on the thermal stability of FeCrNiMnMoxSi0.5B0.5 coatings

2019 ◽  
Vol 35 (11) ◽  
pp. 962-969 ◽  
Author(s):  
Ying Zhu ◽  
Xiong Ya Guo ◽  
Cheng Wen Liu ◽  
Fang Zhou ◽  
Bin Qi Liu
Keyword(s):  
Thermal Stability ◽  
Annealing Temperature ◽  
Thermal Stability Of
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