Restricted Novel Heat Treatments for Obtaining High Jc in Nb- 46.5 WT.%Ti: II. Prestrain Dependence

1994 ◽  
pp. 725-732 ◽  
Author(s):  
Peter J. Lee ◽  
James C. McKinnell ◽  
David C. Larbalestier
Keyword(s):  
Heat Treatments

Influence of Heat Treatments on Microstructures in an Fe-Co-V Alloy

1974 ◽  
Vol 32 ◽  
pp. 512-513
Author(s):  
S. Mahajan ◽  
M. R. Pinnel ◽  
J. E. Bennett
Keyword(s):  
Single Phase ◽  
Alloy Composition ◽  
Supersaturated Solid Solution ◽  
Cell Formation ◽  
Heat Treatments ◽  
Air Cooling ◽  
Iced Brine ◽  
Transmission Electron ◽  
The Matrix ◽  
Bcc Structure

The microstructural changes in an Fe-Co-V alloy (composition by wt.%: 2.97 V, 48.70 Co, 47.34 Fe and balance impurities, such as C, P and Ni) resulting from different heat treatments have been evaluated by optical metallography and transmission electron microscopy. Results indicate that, on air cooling or quenching into iced-brine from the high temperature single phase ϒ (fcc) field, vanadium can be retained in a supersaturated solid solution (α2) which has bcc structure. For the range of cooling rates employed, a portion of the material appears to undergo the γ-α2 transformation massively and the remainder martensitically. Figure 1 shows dislocation topology in a region that may have transformed martensitically. Dislocations are homogeneously distributed throughout the matrix, and there is no evidence for cell formation. The majority of the dislocations project along the projections of <111> vectors onto the (111) plane, implying that they are predominantly of screw character.

Microstructural Development in Nb-Ti Multifilamentary Superconductors During Processing

1985 ◽  
Vol 43 ◽  
pp. 190-191
Author(s):  
A. W. West
Keyword(s):  
Heat Treatment ◽  
Critical Current Density ◽  
Copper Matrix ◽  
Wire Drawing ◽  
Heat Treatments ◽  
Microstructural Development ◽  
Final Size ◽  
Density Values ◽  
The Wire ◽  
Multifilamentary Superconductors

The influence of the filament microstructure on the critical current density values, Jc, of Nb-Ti multifilamentary superconducting composites has been well documented. However the development of these microstructures during composite processing is still under investigation.During manufacture, the multifilamentary composite is given several heat treatments interspersed in the wire-drawing schedule. Typically, these heat treatments are for 5 to 80 hours at temperatures between 523 and 573K. A short heat treatment of approximately 3 hours at 573K is usually given to the wire at final size. Originally this heat treatment was given to soften the copper matrix, but recent work has shown that it can markedly change both the Jc value and microstructure of the composite.

Microstructure Development in a High Current Density NbTi Superconducting Composite

1985 ◽  
Vol 43 ◽  
pp. 186-189
Author(s):  
P. J. Lee ◽  
D. C. Larbalestier
Keyword(s):  
Current Density ◽  
High Current Density ◽  
Cold Drawing ◽  
Heat Treatments ◽  
Grain Structure ◽  
Fine Grain ◽  
Boundary Film ◽  
Quantitative Basis ◽  
Cold Worked ◽  
Very High

Several features of the metallurgy of superconducting composites of Nb-Ti in a Cu matrix are of interest. The cold drawing strains are generally of order 8-10, producing a very fine grain structure of diameter 30-50 nm. Heat treatments of as little as 3 hours at 300 C (∼ 0.27 TM) produce a thin (1-3 nm) Ti-rich grain boundary film, the precipitate later growing out at triple points to 50-100 nm dia. Further plastic deformation of these larger a-Ti precipitates by strains of 3-4 produces an elongated ribbon morphology (of order 3 x 50 nm in transverse section) and it is the thickness and separation of these precipitates which are believed to control the superconducting properties. The present paper describes initial attempts to put our understanding of the metallurgy of these heavily cold-worked composites on a quantitative basis. The composite studied was fabricated in our own laboratory, using six intermediate heat treatments. This process enabled very high critical current density (Jc) values to be obtained. Samples were cut from the composite at many processing stages and a report of the structure of a number of these samples is made here.

Output Voltage Characteristics of Eddy Current Displacement Sensor for Various Heat Treatments of Measuring Objects

2008 ◽  
Vol 128 (4) ◽  
pp. 289-297 ◽  
Author(s):  
Tsutomu Mizuno ◽  
Shigemi Enoki ◽  
Takashi Asahina ◽  
Takayuki Suzuki ◽  
Hiroyuki Maeda ◽  
...  
Keyword(s):  
Eddy Current ◽  
Output Voltage ◽  
Heat Treatments ◽  
Displacement Sensor

Analysis of the effect of Heat Treatments in the manufacturing process of Shape Memory Alloy Springs

2017 ◽  
Author(s):  
Ricardo Alexandre Amar de Aguiar ◽  
Pedro Manuel Calas Lopes Pacheco ◽  
Brenno Tavares Duarte
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Manufacturing Process ◽  
Heat Treatments

Quantitative Microstructural Analysis of a Ni-based Superalloy After Different Heat Treatments

2020 ◽  
Vol 70 (12) ◽  
pp. 4519-4524
Keyword(s):  
Heat Treatment ◽  
Internal Structure ◽  
Microstructural Analysis ◽  
Temperature Treatment ◽  
Heat Treatments ◽  
Metal Melts ◽  
Metallic Inclusions ◽  
Undercooled Melt ◽  
Super Alloy

The efficiency of time-temperature treatment (T-TT) on metal melts can be microstructurally analysed through their degree of purity in non-metallic inclusions. In the case of the Ni-based super alloy under discussion (MSRR 7045) the heat treatment was the undercooling consequences both on the durability of the casting environment (ingots-refractories) and on the internal structure of the metal (porosity, microstructural isotropy). Keywords: time-temperature treatment, undercooled melt, non-metallic inclusions, purity, microstructural isotropy

Effect of Heat Treatments on the Mechanical Properties of a Form Tool

2018 ◽  
Vol 10 (3) ◽  
pp. 03032-1-03032-3
Author(s):  
Brahim Chermime ◽  
◽  
Abdelaziz Abboudi ◽  
Hamid Djebaili ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatments
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