scholarly journals Phase Formation during Heating of Amorphous Nickel-Based BNi-3 for Joining of Dissimilar Cobalt-Based Superalloys

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4600
Author(s):  
Mojtaba Naalchian ◽  
Masoud Kasiri-Asgarani ◽  
Morteza Shamanian ◽  
Reza Bakhtiari ◽  
Hamid Reza Bakhsheshi-Rad ◽  
...  

Phase transformations and the melting range of the interlayer BNi-3 were investigated by differential scanning calorimetry, which showed three stages of crystallization during heating. There were three exothermic peaks that indicated crystallization in the solid state. The cobalt-based X-45 and FSX-414 superalloys were bonded with interlayer BNi-3 at a constant holding time of 10 min with bonding temperatures of 1010, 1050, 1100, and 1150 °C using a vacuum diffusion brazing process. Examination of microstructural changes in the base metals with light microscopy and scanning electron microscopy coupled with X-ray spectroscopy based on the energy distribution showed that increasing temperature caused a solidification mode, such that the bonding centerline at 1010 °C/10 min included a γ-solid solution, Ni3B, Ni6Si2B, and Ni3Si. The athermally solidified zone of the transient liquid phase (TLP)-bonded sample at 1050 °C/10 min involved a γ-solid solution, Ni3B, CrB, Ni6Si2B, and Ni3Si. Finally, isothermal solidification was completed within 10 min at 1150 °C. The diffusion-affected zones on both sides had three distinct zones: a coarse block precipitation zone, a fine and needle-like mixed-precipitation zone, and a needle-like precipitation zone. By increasing the bonding temperature, the diffusion-affected zone became wider and led to dissolution.

2014 ◽  
Vol 33 (6) ◽  
pp. 525-529 ◽  
Author(s):  
X.Y. Gu ◽  
Z.Z. Duan ◽  
X.P. Gu ◽  
D.Q. Sun

AbstractIn the present study microstructural evolution in transient liquid phase (TLP) bonded Ti3Al-Nb alloy joints using a pure copper as interlayer was investigated. TLP bonded Ti3Al-Nb alloy joints composed of intermetallic compound layers were produced. Microstructural evolution of joints depended on both bonding time and bonding temperature. With increasing bonding time and bonding temperature, the joint width increased and amount of compounds in the joint decreased. The joint microstructure at 1173 K × 1 min mainly consisted of Ti (solid solution) + Ti2Cu + TiCu + Ti3Cu4 + Ti2Cu3 + TiCu4 + Cu (solid solution) phase and it changed to Ti (solid solution) + Ti2Cu + TiCu at 1223 K × 60 min. Compounds formed on cooling from the bonding temperature by liquid phase were eliminated from the joint at 1223 K × 60 min due to isothermal solidification of liquid phase. The increase of the width of joint is attributed to the composition difference between the isothermal solidification production and its adjacent base material.


2004 ◽  
Vol 449-452 ◽  
pp. 133-136 ◽  
Author(s):  
Woo Hyuk Choi ◽  
Sung Wook Kim ◽  
Chang Hee Lee ◽  
Jung Cheol Jang

This study was carried out to investigate the effect of heating rate on dissolution and solidification behavior during transient liquid phase diffusion bonding of Ni-based superalloy GTD-111. The heating rate was varied by 0.1K/sec, 1K/sec, 10K/sec to the bonding temperatures 1373K and 1423K in vacuum. When the heating rate was slower and the bonding temperature was higher, the completion time of dissolution after reaching bonding temperature decreased. When the heating rate was very slow, the solidification proceeded before reaching bonding temperature and the time required for the completion of isothermal solidification was shorter. However, when the total time required for completion of solidification from the beginning of heating was considered, heating at 0.1K/sec was nearly the same as heating at 10K/sec.


2018 ◽  
Vol 53 (2) ◽  
pp. 147-160 ◽  
Author(s):  
D. H. Jung ◽  
A. Sharma ◽  
M. Mayer ◽  
J. P. Jung

Abstract In this study, the authors have reviewed recent advances on the transient liquid phase (TLP) bonding technology for various applications especially power module packaging in view of the recent increasing demand for the production of vehicles, smartphones, semiconductor devices etc. TLP bonding is one of the potential technologies from clean technology that can replace the Pb-base solder technology without causing any serious environmental issues. It is based on the concept of both brazing as well as diffusion bonding. During TLP bonding, the liquid phase is transiently formed at the bonding interface. At this point, the melting point of filler metal increases due to the diffusion of element which degrades the melting point from liquid phase to base metal. Subsequently, the bonding occurs by isothermal solidification at the bonding temperature of liquid phase. Here, after bonding, the melting temperature of the joint layer becomes higher than bonding temperature. This review introduces the various aspects of TLP bonding including its principle, materials, applications, advantages and properties in detail.


2006 ◽  
Vol 118 ◽  
pp. 65-70 ◽  
Author(s):  
Bong Keun Lee ◽  
Woo Young Song ◽  
Tae Kyo Han ◽  
Chang Ho Ye ◽  
Hyong Chol Whang ◽  
...  

In the case of transient liquid phase diffusion bonding with Ni base superalloy GTD-111, the bonding temperature was sustained at 1403K ~ 1453K. Thus, the microstructure of specimens heated at 1403K ~ 1453K was examined. In the raw material, γ-γ' eutectic phases, platelet η phases, MC carbide and PFZ were clearly observed in interdendritic regions or near the grain boundary and the size of primary γ' precipitates near the interdendritic regions were larger than the core. The primary γ' precipitated in the dendrite core dissolved early in the bonding process. γ' precipitated near the interdendritic regions were partially solubilized and their shape was changed. The dissolution rate increased with increasing temperature. Phases in the interdendritic regions or near the grain boundary changed continuously with time at the bonding temperature. At a bonding temperature of 1403K, the eutectic phases remained, but η phases were transformed from a platelet shape to a needle morphology and the PFZ region widened with time. The interdendritic region and near the grain boundary became partially liquid at 1423K and fully at 1453K by the reaction of η phases and PFZ. The interdendritic region and near grain the boundary became liquid and new phases which were mixed with η phases, PFZ and MC carbide crystallized during cooling at 1453K. Crystalline η phases were transformed from a rod shape to a platelet shape with increasing holding time.


Author(s):  
Mohamed I. Saleh ◽  
Hans J. Roven ◽  
Tahir I. Khan ◽  
Treje Iveland

Transient liquid phase (TLP) bonding of Al-6063 and UNS S32304 was performed using copper foil as an interlayer between the base metals. A compression load was applied normal to the specimens. Metallurgical examination of the produced joints showed three distinct regions including a reaction zone, diffusion affected zone and the base metals. The diffusion of copper into aluminum resulted in an Al-Cu eutectic structure. However, the oxide layer on the aluminum surface controlled the dissolution behavior of copper and the extent of its wettability with the base metals. Although voids and intermetallic compounds were detected at the interfaces of the processed joints, a defect free joint was produced at 570°C. In addition, the results from corrosion tests showed that the use of copper as an interlayer decreased the corrosion resistance of the joints. However, increase in thickness of the joining reaction zone with increasing bonding temperature was observed to increase corrosion resistance.


2020 ◽  
Vol 9 (5) ◽  
pp. 10355-10365
Author(s):  
Alireza Doroudi ◽  
Ali Ebrahimzadeh Pilehrood ◽  
Mohammadjavad Mohebinia ◽  
Ali Dastgheib ◽  
Armin Rajabi ◽  
...  

2011 ◽  
Vol 46 (16) ◽  
pp. 5305-5323 ◽  
Author(s):  
Grant O. Cook ◽  
Carl D. Sorensen

AbstractTransient liquid phase (TLP) bonding is a relatively new bonding process that joins materials using an interlayer. On heating, the interlayer melts and the interlayer element (or a constituent of an alloy interlayer) diffuses into the substrate materials, causing isothermal solidification. The result of this process is a bond that has a higher melting point than the bonding temperature. This bonding process has found many applications, most notably the joining and repair of Ni-based superalloy components. This article reviews important aspects of TLP bonding, such as kinetics of the process, experimental details (bonding time, interlayer thickness and format, and optimal bonding temperature), and advantages and disadvantages of the process. A wide range of materials that TLP bonding has been applied to is also presented. Partial transient liquid phase (PTLP) bonding is a variant of TLP bonding that is typically used to join ceramics. PTLP bonding requires an interlayer composed of multiple layers; the most common bond setup consists of a thick refractory core sandwiched by thin, lower-melting layers on each side. This article explains how the experimental details and bonding kinetics of PTLP bonding differ from TLP bonding. Also, a range of materials that have been joined by PTLP bonding is presented.


2013 ◽  
Vol 712-715 ◽  
pp. 701-704
Author(s):  
Xue Gang Wang ◽  
Xin Geng Li

A novel two-step heating process, consisting of a short-time high temperature heating followed by isothermal solidification at a lower temperature, was used to transient liquid phase (TLP) bond T91 steel. The interface morphology of the joint was investigated and compared with that of conventional TLP bond made at a constant bonding temperature. The results show that the two-step heating process produces a non-planar interface at the initial stage, which is different from the planar interfaces associated with conventional heating process. No interface can be found in the final joint by two-step heating process, however, a planar interface still exists in the final conventional TLP bond. Therefore, the bending ductility of the joint is dramatically improves by the two-step heating process, and the joint properties are similar to that of base metal.


2019 ◽  
Vol 9 (6) ◽  
pp. 1112 ◽  
Author(s):  
Qing He ◽  
Dongdong Zhu ◽  
Duo Dong ◽  
Mengjia Xu ◽  
Anpeng Wang ◽  
...  

The effect of bonding temperature on the microstructure and mechanical properties of transient liquid phase (TLP) joints of GH4169 superalloy was investigated. Joining processes were carried out at 1040–1100 °C for 30 min using BNi-2 solder paste. The results showed that three distinct microstructural zones were formed in the joint region: an athermal solidification zone (ASZ), consisting of eutectic compounds; an isothermal solidification zone (ISZ), consisting of γ solid solution; and a diffusion affected zone (DAZ), consisting of Ni-Cr rich boride and Cr-Nb-Mo-rich boride compounds. With increasing bonding temperature, the amounts of eutectic compounds in ASZ first decreased and then increased. A eutectic-free joint centerline was obtained at 1080 °C. The maximum bonding shear strength reached 728.03 MPa due to the completion of isothermal solidification. Fractographic studies revealed that the boride compounds in ASZ and the intermetallic compounds in DAZ were the main causes for the failure of joints. The fracture mode of the sample bonded at 1040 °C was brittle, and the fracture path was along the ASZ. However, the fracture mode of the sample bonded at 1080 °C was ductile, and the fracture occurred along the DAZ.


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