Interfacial Microstructure Investigation of Diffusion Bonded New Ni-Cr-W Superalloy Using Cu Interlayer

2013 ◽  
Vol 634-638 ◽  
pp. 1844-1849 ◽  
Author(s):  
Rui Hu ◽  
Xian Lin Meng ◽  
Bin Tang ◽  
Chuan Yun Wang ◽  
Hong Chao Kou ◽  
...  
Keyword(s):  
Solid State ◽  
Bonding Temperature ◽  
Interfacial Microstructure ◽  
Vacuum Furnace ◽  
Solid State Diffusion ◽  
Diffusion Behavior ◽  
State Diffusion ◽  
Different Temperatures ◽  
Cu Foil ◽  
Cu Interlayer

The solid-state diffusion bonding processes were successfully carried out to join new Ni-Cr-W superalloys at different temperatures (850°C-950°C), under pressures of 20MPa and holding 45min in a vacuum furnace by taking Cu foil as interlayer. The influence of bonding temperature on the microstructural evolution and the diffusion behavior across the joints was investigated in details. Results indicate that the Ni-Cu solid solutions in the interface lead to a sound bonding interface without any void or impurity. As the temperature increases, the reaction layers become thicker due to the decrease of M23C6 precipitation in the grain boundaries and the rise of atoms diffusion capability. Furthermore, hardness measuremental result also reveals that the increased thickness of reaction layers cannot improve the microhardness of bonding interfaces apparently.

Investigation of the diffusion behavior in Sn-xAg-yCu/Cu solid state diffusion couples

2016 ◽  
Vol 686 ◽  
pp. 794-802 ◽  
Author(s):  
Yuan Yuan ◽  
Dajian Li ◽  
Yuanyuan Guan ◽  
Hans J. Seifert ◽  
Nele Moelans
Keyword(s):  
Solid State ◽  
Solid State Diffusion ◽  
Diffusion Couples ◽  
Diffusion Behavior ◽  
State Diffusion

Solid-State Diffusion Bonding of Titanium by Using Metal Salt Coated Aluminum Sheet

2017 ◽  
Vol 741 ◽  
pp. 31-35
Author(s):  
Shinji Koyama ◽  
Van Phu Nguyen
Keyword(s):  
Solid State ◽  
Metal Salt ◽  
Bonding Temperature ◽  
High Strength ◽  
Bonding Process ◽  
Aluminum Surface ◽  
Solid State Diffusion ◽  
State Diffusion ◽  
Aluminum Surfaces ◽  
Salt Coating

In this study, the effect of metal salt coating processing of aluminum surface on the bond strength of the solid-state diffusion bonded interface of titanium and aluminum has been investigated by SEM observation of the interfacial microstructures and fractured surfaces after tensile test. Aluminum surfaces were coated by boiling in 5% aqueous solution of NaOH for 90 s and 98% formic acid for 60 s. Bonding process was performed at a bonding temperature of 713 ~ 773 K under a load of 12 MPa (for a bonding time of 900 s). As a result of the metal salt coating processing, high strength joint can be achieved with lower bonding temperature compared with unmodified joints. From this study, it is found out that metal salt coating processing is effective at removing oxide film and substitution to metal salt on the aluminum bonding surface.

Bonding γ-TiAl Alloys Using Ti/Al Nanolayers Doped with Ag

2008 ◽  
Vol 587-588 ◽  
pp. 488-491 ◽  
Author(s):  
Liliana I. Duarte ◽  
Filomena Viana ◽  
Manuel F. Vieira ◽  
Ana Sofia Ramos ◽  
M. Teresa Vieira ◽  
...  
Keyword(s):  
Solid State ◽  
Diffusion Bonding ◽  
Titanium Aluminide ◽  
Titanium Aluminides ◽  
Bonding Temperature ◽  
Bonding Interface ◽  
Chemical Compositions ◽  
Solid State Diffusion ◽  
Fine Grained ◽  
State Diffusion

Successful solid state bonding of titanium aluminides requires the use of high temperature and pressure. In previous works, authors have demonstrated that the use of Ti/Al multilayer thin film as an interlayer, deposited by d.c. magnetron sputtering onto the joining surfaces, can effectively lower the bonding temperature. The enhanced diffusivity of these nanometric layers and the heat evolved by the formation of γ-TiAl improves the joinability of titanium aluminide by solid-state diffusion bonding. In the present work, further improvement of the process was pursued by doping the interlayer with 2.8 at.% of Ag; previous studies have confirmed that silver favours the transformation Ti+Al→γ-TiAl. The solid-state diffusion bonding experiments were performed in vacuum by applying 50 MPa at 900°C for 1 h. The effect of the third element on the microstructure and chemical composition along the bonding interface has been analyzed. Microstructural characterisation of the interface was performed by scanning and transmission electron microscopy. Chemical compositions were analysed by energy dispersive X-ray spectroscopy. No defects were observed at the interface and sound bonding was achieved between the interlayers and base γ-TiAl. The bonding interface shows a fine-grained microstructure, slightly coarser than the one formed at the same temperature with the undoped Ti/Al multilayer.

Metallurgists’ Insights on Diffusion-Assisted Dissimilar-Joints of Light- and Heavy-Alloys

2017 ◽  
Vol 380 ◽  
pp. 12-28 ◽  
Author(s):  
Gopinath Thirunavukarasu ◽  
Sukumar Kundu ◽  
Subrata Chatterjee
Keyword(s):  
Solid State ◽  
Integrated Circuits ◽  
Inner Core ◽  
Diffusion Mechanism ◽  
Bonding Temperature ◽  
High Vacuum ◽  
Solid State Diffusion ◽  
Dissimilar Metals ◽  
Dissimilar Joints ◽  
State Diffusion

In metallurgy and materials engineering, a number of phase transformation in solids like precipitation, oxidation, creep, annealing, homogenization, etc. are brought about by the process of diffusion. Many industrial manufacturing processes utilize solid-state diffusion principle, to name a few: 1. Rotating or sliding parts of steel have a hard outside case for wear resistance and a tough inner core for fracture resistance by gas carburizing procedure; 2. Integrated circuits were produced by diffusing impurity into silicon wafers; and 3. Joints between similar and dissimilar metals, alloys, and non-metals, were made using diffusion bonding (DB) technique. Day by day, the science of solid-state diffusion phenomenon is spreading inevitably into new areas of engineering and technology. Diffusion-Assisted-Joints (DAJs) meet the requirements for most critical structures in terms of strength, toughness, tightness, and resistance to heat and corrosion. DAJs can be made out of 730 pairs of dissimilar metals. Hence, DB is considered as an engineering marvel among all the physical welding metallurgists. Herein, experiments were performed to exactly map the quantum influence of the bonding temperature variation on the dissimilar joints of a popular light alloy, Ti-6Al-4V (TiA), and a heavily used heavy alloy, stainless steel (SS), using diffusion mechanism in high-vacuum environment. Cu foil (~200μm) was used as an interlayer. Necessary characterization tools for metallurgical investigations were used to understand the extent of diffusion along the TiA/Cu and Cu/SS interfaces, room-temperature mechanical properties, fracture morphologies, and fracture path of the TiA/Cu/SS DAJs. This paper discussed rational reasons backing the results of the characterizations.

Microstructure of SiC / TiAl Interface Formed by Solid-State Diffusion Bonding

2005 ◽  
Vol 502 ◽  
pp. 461-466
Author(s):  
Masakatsu Maeda ◽  
Kazuyuki Tenyama ◽  
Toshiya Shibayanagi ◽  
Masaaki Naka
Keyword(s):  
Solid State ◽  
Diffusion Bonding ◽  
Titanium Aluminide ◽  
Chemical Potential ◽  
Interfacial Microstructure ◽  
Solid State Diffusion ◽  
Reaction Products ◽  
Phase Sequence ◽  
Heat Treated ◽  
State Diffusion

The microstructure of the solid-state diffusion bonded interfaces of silicon carbide (SiC) and titanium aluminide (TiAl) were investigated. A 100-µm-thick Ti-48at%Al foil was inserted between two SiC specimens and then heat-treated in vacuum. The interfacial microstructure has been analyzed by scanning electron microscopy, electron probe microanalysis and X-ray diffractometry. Four layers of reaction products are formed at the interface by diffusion bonding: a layer of TiC adjacent to SiC followed by a diphase layer of TiC+Ti2AlC, a layer of Ti5Si3CX containing Ti2AlC particles and a layer of TiAl2. However, the TiAl2 layer is formed during cooling. The actual phase sequence at the bonding temperatures of 1573 K and 1673 K are described as SiC/TiC/(TiC+ Ti2AlC)/(Ti5Si3CX+Ti2AlC)/Ti1-XAl1+X/TiAl and SiC/TiC/(TiC+Ti2AlC)/(Ti5Si3CX+Ti2AlC)/Ti5Al11 /Ti1-XAl1+X/TiAl, respectively. The phase sequences are successfully expressed on the basis of the Ti-Al-Si-C quaternary chemical potential diagram.

scholarly journals Investigation of diffusion behavior in Cu–Sn solid state diffusion couples

2016 ◽  
Vol 661 ◽  
pp. 282-293 ◽  
Author(s):  
Yuan Yuan ◽  
Yuanyuan Guan ◽  
Dajian Li ◽  
Nele Moelans
Keyword(s):  
Solid State ◽  
Solid State Diffusion ◽  
Diffusion Couples ◽  
Diffusion Behavior ◽  
State Diffusion
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