The Effect of Diffusion Annealing of Nb3Sn-Based Superconductors with Internal Tin Sources on the Conductivity of Stabilizing Copper

2021 ◽  
Vol 122 (1) ◽  
pp. 33-39
Author(s):  
D. S. Novosilova ◽  
M. V. Polikarpova ◽  
I. M. Abdyukhanov ◽  
I. L. Deryagina ◽  
E. N. Popova ◽  
...  
Keyword(s):  
Diffusion Annealing

BÖHLER W403 VMR

Alloy Digest ◽  
2013 ◽  
Vol 62 (9) ◽  
Keyword(s):  
Heat Treatment ◽  
Chemical Composition ◽  
Physical Properties ◽  
Tool Steel ◽  
Raw Materials ◽  
Heat Treating ◽  
Diffusion Annealing ◽  
Selection Of

Abstract Böhler (or Boehler) W403 VMR is a tool steel with outstanding properties, based not only on a modified chemical composition, but on the selection of highly clean raw materials for melting, remelting under vacuum (VMF), optimized diffusion annealing, and a special heat treatment. This datasheet provides information on composition, physical properties, and elasticity. It also includes information on forming and heat treating. Filing Code: TS-721. Producer or source: Böhler Edelstahl GmbH.

In Situ X-Ray Diffraction Investigations during Diffusion Anneals of Ni-Cu Thin Film Diffusion Couples

2010 ◽  
Vol 89-91 ◽  
pp. 503-508 ◽  
Author(s):  
J. Sheng ◽  
U. Welzel ◽  
Eric J. Mittemeijer
Keyword(s):  
Thermal Stresses ◽  
Stress Generation ◽  
Ex Situ ◽  
Diffusion Annealing ◽  
X Ray Diffraction ◽  
Individual Layer ◽  
X Ray ◽  
Bilayer System ◽  
Stress Changes

The stress evolution during diffusion annealing of Ni-Cu bilayers (individual layer thicknesses of 50 nm) was investigated employing ex-situ and in-situ X-ray diffraction measurements. Annealing at relatively low homologous temperatures (about 0.3 - 0.4 Tm) for durations up to about 100 hours results in considerable diffusional intermixing, as demonstrated by Auger-electron spectroscopy investigations (in combination with sputter-depth profiling). In addition to thermal stresses due to differences of the coefficients of thermal expansion of layers and substrate, tensile stress con-tributions in the sublayers arise during the diffusion anneals. The obtained stress data have been discussed in terms of possible mechanisms of stress generation. The influence of diffusion on stress development in the sublayers of the diffusion couple during heating and isothermal annealing was investigated by comparing stress changes in the bilayer system with corresponding results obtained under identical conditions for single layers of the components in the bilayer system. The specific residual stresses that emerge due to diffusion between the (sub)layers in the bilayer could thereby be identified.

Quantitative Evaluation of Alitize Coating on ŽS6K Ni-Base Superalloy

2014 ◽  
Vol 782 ◽  
pp. 578-583 ◽  
Author(s):  
Juraj Belan
Keyword(s):  
Turbine Blades ◽  
Advanced Materials ◽  
Diffusion Annealing ◽  
Jet Engines ◽  
Unique Combination ◽  
Jet Engine ◽  
Working Temperature ◽  
Aerospace Applications ◽  
Mechanical And Physical Properties ◽  
Base Superalloy

The aerospace industry is one of the biggest consumers of advanced materials because of its unique combination of mechanical and physical properties and chemical stability. Highly alloyed stainless steel, titanium alloys and nickel based superalloys are mostly used for aerospace applications. The aim of the work is to evaluate protective Al Si coating applied by diffusion annealing on substrate, Ni base superalloy ZS6K. This superalloy is used for turbine blade production in aero jet engine DV 2. Using of protective alitize coating provides an increasing of heat resistance of superalloy surface and increases working temperature up to 800°C. However, overcrossing of working temperature range (for ZS6K turbine blades it is from 705°C to 750°C) sometimes happen and that is the reason for detailed study of protective coating degradation. The alitize coating were evaluated in starting stage and after various time of regular loading in real aero jet engines DV 2. Coating and its degradation was evaluated with help of quantitative metallography methods (metallography software NIS Elements) and colour contrast as well.

Influence of Phases Stability on the Hydrogen Diffusion Coefficient in Ti-6Al-4V

2020 ◽  
Vol 986 ◽  
pp. 33-40
Author(s):  
Mohammed Kasim Mohsun
Keyword(s):  
Heat Treatment ◽  
Diffusion Coefficient ◽  
Titanium Alloys ◽  
Hydrogen Diffusion ◽  
Volume Fraction ◽  
Substantial Effect ◽  
Diffusion Annealing ◽  
Hydrogen Treatment ◽  
Β Phase ◽  
Hydrogen Diffusion Coefficient

For a unique microstructure creation, thermo-hydrogen treatment (THT), using hydrogen as a temporary alloying element within the heat treatment, is applied. This advanced heat treatment requires reliable data about the hydrogen diffusion coefficient (DH) for understanding diffusion kinetics and its effect on the mechanical behavior of the resulted phases. In this research, three different homogeneous microstructures were established for the investigation using different homogenization parameters. After that, the concentration of hydrogen, charged in the half-length of thin titanium rods via electrochemical hydrogenation, is specified. Then, a diffusion annealing heat treatment was carried out at different temperatures, leading to hydrogen diffusion in the hydrogenated specimens. Furthermore, DH was systematically determined using two methods including the explicit finite difference method (EFDM) and Matano technique (MT). For this purpose, Abaqus software was employed for modeling the hydrogen gradient established in the specimens. Additionally, scanning electron microscopy (SEM) was used for the microstructure examination in order to specify the influence of different hydrogen concentrations on the hydrogenated specimens. The experimental outcomes reveal a substantial effect of the β phase stability and grains sizes of the β and α phases on the hydrogen diffusion. Correspondingly, the results confirm that DH was independent of the hydrogen concentration, and obeys an Arrhenius-type temperature dependence. Furthermore, hydrogen diffusion in the α+β titanium alloys Ti-6Al-4V was slower in comparison to the hydrogen diffusion in the metastable β titanium alloys Ti-10V-2Fe-3Al. In conclusion, it was observed that DH is influenced by the previously performed heat treatments that determine the resulted microstructure types, and a slight influence of the volume fraction of the α phase on DH was observed as well.

Effect of Annealing on Nanocrystalline Structure of Nb3Sn Diffusion Layers in Composites with Internal Tin Sources

2010 ◽  
Vol 297-301 ◽  
pp. 126-131 ◽  
Author(s):  
E.N. Popova ◽  
Vladimir V. Popov ◽  
E.P. Romanov ◽  
S.V. Sudareva ◽  
L.V. Elohina ◽  
...  
Keyword(s):  
Grain Size ◽  
Carrying Capacity ◽  
Nanocrystalline Structure ◽  
Diffusion Annealing ◽  
External Diameter ◽  
High Temperature Annealing ◽  
Grain Sizes ◽  
Diffusion Layers ◽  
Average Grain Size ◽  
Complete Transformation

Multifilamentary Nb3Sn-based superconducting composites manufactured by an internal-tin method have been studied by transmission (TEM) and scanning (SEM) electron microscopy. The main goal of this study is to reveal the effect of diffusion annealing regimes as well as the external diameter of the wires on the structure of nanocrystalline Nb3Sn layers (average grain size, grain size distribution, layer thickness, amount of Sn, etc.). It is demonstrated that multistep diffusion annealing results in quite a complete transformation of Nb filaments into Nb3Sn though some amount of the residual Nb remains in the filaments center. With an external diameter decrease the superconducting layers structure has been found to refine and get somewhat more uniform. An additional high-temperature annealing results in marked growth of Nb3Sn grain sizes and their scattering in sizes, which may negatively affect the current-carrying capacity of a wire.

Solid-State Diffusion Formation of Nanocrystalline Nb3Sn Layers at Two-Staged Annealing of Multifilamentary Nb/Cu-Sn Wires

2012 ◽  
Vol 16 ◽  
pp. 69-75 ◽  
Author(s):  
E.N. Popova ◽  
I.L. Deryagina ◽  
E.P. Romanov ◽  
E.A. Dergunova ◽  
A.E. Vorobyova ◽  
...  
Keyword(s):  
Diffusion Annealing ◽  
Solid State Diffusion ◽  
Superconducting Layer ◽  
Superconducting Wires ◽  
Second Stage ◽  
State Diffusion ◽  
Columnar Grains ◽  
Average Size ◽  
Bronze Matrix ◽  
Active Formation

The structure of Nb3Sn-based, bronze-processed Ti-doped multifilamentary superconducting wires has been studied by TEM and SEM after the first (5750C,100 h) and the second (6500C,100 h) stage of the diffusion annealing. The Nb3Sn layers formation in all the composites proceeds by one and the same mechanism and starts with nucleation of particles and very fine grains of this phase in Nb filaments where Sn diffuses from the bronze matrix. Ti, inserted both in the bronze matrix, or Nb filaments, diffuses into the growing superconducting layer and promotes its more active formation. At the first stage of annealing (5750C, 100 h) Nb3Sn grains have an average size of 40 nm, and at the second stage (6500C, 100 h) they increase by a factor of 1.5 and the grain size distribution gets wider. After the two-stage annealing the amount of the residual niobium is small, and some Nb filaments, especially in doped composites, almost completely transform into Nb3Sn. In the Nb3Sn layers of a zone of columnar grains is adjacent to the residual Nb.

scholarly journals Interfacial Bonding Mechanism Ofaluminium and Steel Composites

2018 ◽  
Vol 27 (2) ◽  
pp. 096369351802700 ◽  
Author(s):  
Xian Yang ◽  
Hao Weng ◽  
Chao-lan Tang
Keyword(s):  
Bonding Strength ◽  
Annealing Treatment ◽  
Physical Contact ◽  
Diffusion Annealing ◽  
Al Alloy ◽  
Bonding Mechanism ◽  
Chemical Action ◽  
Roll Bonding ◽  
Two Component ◽  
Metallic Bonding

The research on singular material is gradually converted to composite material which serves to rectify weaknesses possessed by each constituent when it exists alone. Experiments on Al-alloy 4A60 and 08Al steel plate compounded by cold roll bonding were conducted to analyze the bonding mechanism of the interface during the composite process of laminated metal. SEM, EDS, and laser confocal microscope were used to observe the interface and section of composites while the bonding strength was tested by universal tensile machine. The result showed that bonded metal's surface microtopography, reduction and diffusion annealing were the most critical influences on the bonding of composites, and the roll bonding mechanism of 4A60/08Al composite was divided into three stages: 1) Physical contact. Two component layers were mechanically occluded by the rolling pressure, the bonding strength was low; 2) Metallic bonding. The oxide layer and the hardened layer covered on the metal surface break which made the two component fresh metals to full contact, chemical action happened and metallic bonding formed when the interatomic distance reached a certain stage, the bonding strength increased; 3) Metallurgical bonding. In the subsequent annealing treatment, the bonding strength significantly increased because the diffusion of metal atoms at the interface.

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