High temperature precipitation kinetics and ttt curve of a 7xxx alloy by in-situ electrical resistivity measurements and differential calorimetry

A side-entry type, helium-temperature specimen stage that has the capability of in-situ electrical-resistivity measurements has been designed and developed for use in the AEI-EM7 1200-kV electron microscope at Argonne National Laboratory. The electrical-resistivity measurements complement the high-voltage electron microscope (HVEM) to yield a unique opportunity to investigate defect production in metals by electron irradiation over a wide range of defect concentrations.A flow cryostat that uses helium gas as a coolant is employed to attain and maintain any specified temperature between 10 and 300 K. The helium gas coolant eliminates the vibrations that arise from boiling liquid helium and the temperature instabilities due to alternating heat-transfer mechanisms in the two-phase temperature regime (4.215 K). Figure 1 shows a schematic view of the liquid/gaseous helium transfer system. A liquid-gas mixture can be used for fast cooldown. The cold tip of the transfer tube is inserted coincident with the tilt axis of the specimen stage, and the end of the coolant flow tube is positioned without contact within the heat exchanger of the copper specimen block (Fig. 2).

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Quantitative evaluation of dynamic precipitation kinetics in a complex Nb-Ti-V microalloyed steel using electrical resistivity measurements

Metals and Materials International ◽

10.1007/s12540-013-5035-x ◽

2013 ◽

Vol 19 (5) ◽

pp. 1159-1162 ◽

Cited By ~ 4

Author(s):

Jae-Gil Jung ◽

Jin-Ho Bae ◽

Young-Kook Lee

Keyword(s):

Electrical Resistivity ◽

Quantitative Evaluation ◽

Microalloyed Steel ◽

Dynamic Precipitation ◽

Precipitation Kinetics ◽

Resistivity Measurements

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Electrical Resistivity Measurements of Manganite La0.95Sr0.05MnO3 Under Uniaxial Pressure at High Temperature

Journal of Superconductivity and Novel Magnetism ◽

10.1007/s10948-018-4969-0 ◽

2018 ◽

Vol 32 (8) ◽

pp. 2467-2469

Author(s):

S. Muruganantham ◽

S. Kumararaman ◽

N. R. Tamilselvan ◽

T. Thaila ◽

K. Subbaraman

Keyword(s):

Electrical Resistivity ◽

High Temperature ◽

Uniaxial Pressure ◽

Resistivity Measurements

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YBa2Cu3O7–x:Transport Properties and Defects at High Temperature

Zeitschrift für Naturforschung A ◽

10.1515/zna-1989-1206 ◽

1989 ◽

Vol 44 (12) ◽

pp. 1167-1171 ◽

Cited By ~ 3

Author(s):

G. Chiodelli ◽

G. Campari-Viganò ◽

G. Flor

Keyword(s):

Electrical Resistivity ◽

High Temperature ◽

Tetragonal Phase ◽

Orthorhombic Phase ◽

Ion Migration ◽

Resistivity Measurements ◽

Oxygen Ion ◽

Partial Pressures ◽

Oxygen Ion Migration ◽

The One

Abstract Electrical resistivity measurements were carried out on polycrystalline YBa2Cu3O7-x at temperatures 300 < T < 1023 K and oxygen partial pressures 5 ·10-7 ≤ po2 ≤ 1 atm. The samples, equilibrated in the range from 5 ·10-4 to 1 atm, show metallic behaviour, the one equilibrated at po2 = 2 ·10-5 shows a transition between metallic and semiconducting behaviour at 920 K, and that equilibrated at po2 = 5 ·10-7 shows semiconducting behaviour: for the latter the relevant resistivity is due to the oxygen-ion migration. The isotherms log σ vs. log po2 (in the temperature range from 723 to 1023 K) show slopes of about 1/6 at 723 K (orthorhombic phase) and about 1/2 at 1023 K (tetragonal phase). These results are discussed in terms of appropriate defect models.

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