Manufacture, electromagnetic properties and microstructure of an 18-filament jelly-roll Nb3Al superconducting wire with rapid heating and quenching heat-treatment

ABSTRACTThe surface-front oxidation mechanism of iron was investigated by time-resolved, glancingangle Fe K-edge fluorescence EXAFS measurements at various oxidation temperatures of 200-700 C. The glancing angle was chosen according to the depth of the oxide layer, roughly 1500-2000A. The oxidation behavior under rapid heating(up to 600°C within 10 minutes) was compared with the slowly heated oxidation process using the Quick-EXAFS measurements. In the slowly heated process, Fe3O4 was the dominating phase at a relatively low temperature (300-400 C) initially. However, at a relatively high temperature (above 600°C), the Fe2O3 and FeO crystalline phases are gradually enriched as the successive oxidation process involving intrusive oxygen proceeded. Remarkably under a prolonged heat treatment above 600°C, the stable FeO phase that exists in a deep-lying interface structure and Fe2O3 phase eventually dominates the thick front-surface structure. In a quickly heated process, however, Fe3O4 phase is less dominating, which is contradictory to the commonly accepted oxidation models. The EXAFS results are discussed in conjunction with the x-ray diffraction features under the same heat treatment conditions.

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The Effect of Cooling Rate after Homogenization on the Microstructure and Properties of 2017a Alloy Billets for Extrusion with Solution Heat Treatment on the Press

Archives of Metallurgy and Materials ◽

10.1515/amm-2016-0269 ◽

2016 ◽

Vol 61 (3) ◽

pp. 1663-1670

Author(s):

A. Woźnicki ◽

D. Leśniak ◽

G. Włoch ◽

P. Pałka ◽

B. Leszczyńska-Madej ◽

...

Keyword(s):

Heat Treatment ◽

Cooling Rate ◽

Solution Heat Treatment ◽

Rapid Heating ◽

The Press ◽

Large Particles ◽

Rapid Dissolution ◽

Alloy Microstructure ◽

Fast Dissolution ◽

Short Time

AbstractThe influence of cooling rate after homogenization on the 2017A alloy microstructure was analysed. The capability of the θ (Al2Cu) particles, precipitated during various homogenization coolings, for rapid dissolution was estimated. For this purpose, the DSC test was used to determine the effect of the cooling rate after homogenization on the course of melting during a rapid heating. Moreover, the samples after solution heat treatment (with short time annealing) and ageing, were subjected to the microstructure investigations and the microhardness of grains interiors measurements. It was found that cooling after homogenization at 160 °C/h is sufficient for precipitation of fine θ phase particles, which dissolve during the subsequent rapid heating. The cooling at 40 °C/h, causes the precipitation of θ phase in the form of large particles, incapable of further fast dissolution.

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Variance in the response of silcrete to rapid heating complicates assumptions about past heat treatment methods

Archaeological and Anthropological Sciences ◽

10.1007/s12520-018-0663-1 ◽

2018 ◽

Vol 11 (11) ◽

pp. 5909-5920 ◽

Cited By ~ 2

Author(s):

Alex Mackay ◽

Sam C. Lin ◽

Lachlan S. Kenna ◽

Alex F. Blackwood

Keyword(s):

Heat Treatment ◽

Rapid Heating ◽

Treatment Methods

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Optical microstructure and superconducting properties in jelly-roll Nb/sub 3/Al multifilamentary wire by rapid heating

IEEE Transactions on Applied Superconductivity ◽

10.1109/tasc.2003.812336 ◽

2003 ◽

Vol 13 (2) ◽

pp. 3406-3409 ◽

Cited By ~ 1

Author(s):

N. Harada ◽

H. Yamada ◽

M. Tsuda ◽

T. Hamajima ◽

T. Takeuchi ◽

...

Keyword(s):

Rapid Heating ◽

Superconducting Properties ◽

Optical Microstructure ◽

Jelly Roll

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A New Infrared Heat Treatment on Hot Forging 7075 Aluminum Alloy: Microstructure and Mechanical Properties

Materials ◽

10.3390/ma13051177 ◽

2020 ◽

Vol 13 (5) ◽

pp. 1177 ◽

Cited By ~ 1

Author(s):

Yi-Ling Chang ◽

Fei-Yi Hung ◽

Truan-Sheng Lui

Keyword(s):

Heat Treatment ◽

Aluminum Alloy ◽

High Temperature ◽

Material Property ◽

Rapid Heating ◽

Hot Forging ◽

Target Material ◽

Age Hardening ◽

Experimental Result ◽

7075 Aluminum Alloy

When hot forging 7075 aluminum alloy, as a military material durable enough for most of its applications, it needs to be heat-treated to ensure the target material property achieves the application requirements. However, the material properties change because of heat throughout usage. In this study, a new approach was devised to heat treat the alloy to prevent material property changes. The study further clarified the effect of rapid heat treatment on the high-temperature resistance of a hot forging 7075 aluminum alloy. Infrared (IR) heat treatment was used as a rapid heating technique to effectively replace the conventional resistance heat (RH) treatment method. Our experimental result showed that IR heat treatment resulted in better age hardening at the initial aging stage, where its tensile strength and elongation appeared like that of a resistance heat treatment. More so, based on hardness and tensile test results, the IR-heated treatment process inhibited the phase transformation of precipitations at a higher temperature, improving high-temperature softening resistance and enhancing the thermal stability of the hot forging 7075 aluminum alloy.

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