scholarly journals Microstructure and Mechanical Properties of Diffusion-Bonded CoCrNi-Based Medium-Entropy Alloy to DD5 Single-Crystal Superalloy Joint

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1127
Author(s):  
Shiwei Li ◽  
Xianjun Sun ◽  
Yajie Du ◽  
Yu Peng ◽  
Yipeng Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Single Crystal ◽  
Diffusion Zone ◽  
Diffusion Bonding ◽  
Bonding Temperature ◽  
Single Crystal Superalloy ◽  
Interface Bonding ◽  
Microstructure And Mechanical Properties ◽  
Joint Diffusion

This study focuses on the diffusion bonding of a CoCrNi-based medium-entropy alloy (MEA) to a DD5 single-crystal superalloy. The microstructure and mechanical properties of the joint diffusion-bonded at variable bonding temperatures were investigated. The formation of diffusion zone, mainly composed of the Ni3(Al, Ti)-type γ′ precipitates and Ni-rich MEA matrix, effectively guaranteed the reliable joining of MEA and DD5 substrates. As the bonding temperature increased, so did the width of the diffusion zone, and the interfacial microvoids significantly closed, representing the enhancement of interface bonding. Both tensile strength and elongation of the joint diffusion-bonded at 1110 °C were superior to those of the joints diffusion-bonded at low temperatures (1020, 1050, and 1080 °C), and the maximum tensile strength and elongation of 1045 MPa and 22.7% were obtained. However, elevated temperature produced an adverse effect that appeared as grain coarsening of the MEA substrate. The ductile fracture of the joint occurred in the MEA substrate (1110 °C), whereas the tensile strength was lower than that of the MEA before diffusion bonding (approximately 1.3 GPa).

Forming Behaviour of Al-TiC In Situ Composites

2013 ◽  
Vol 765 ◽  
pp. 418-422 ◽  
Author(s):  
Ram Naresh Rai ◽  
A.K. Prasada Rao ◽  
G.L. Dutta ◽  
M. Chakraborty
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Uniform Distribution ◽  
Interface Bonding ◽  
Microstructure And Mechanical Properties ◽  
Micron Size ◽  
Forming Behaviour ◽  
Al Matrix

The forming behaviour of in-situ Al-TiC composites was investigated by comparing microstructure and mechanical properties of as-cast, forged and rolled specimens. The microstructures of forged and rolled specimens reveal uniform distribution of the TiC particles, which are responsible for the enhancement of the tensile strength of the composite. The formed samples were found to be crack free. This feature is very likely to be due to good interface bonding of uniformly dispersed sub-micron size TiC particles with the Al matrix.

scholarly journals Microstructure and mechanical properties of a new nickel-based single crystal superalloy

2020 ◽  
Vol 9 (5) ◽  
pp. 11641-11649 ◽  
Author(s):  
Zhao Shang ◽  
Xianping Wei ◽  
Dazhuo Song ◽  
Juntao Zou ◽  
Shuhua Liang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Single Crystal Superalloy ◽  
Microstructure And Mechanical Properties

scholarly journals Microstructure and Mechanical Properties of Vacuum Diffusion Bonded Zr-4 Alloy Joint

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1437
Author(s):  
Zeming Wang ◽  
Xu Yang ◽  
Jing Wang ◽  
Zhonglin Xiao ◽  
Fugong Qi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Diffusion Bonding ◽  
Nuclear Reactor ◽  
Bonding Temperature ◽  
Base Material ◽  
Interfacial Microstructure ◽  
Second Phase ◽  
Microstructure And Mechanical Properties ◽  
Diffusion Temperature

The development of welding technology for zirconium alloy has great significance on the safety, stability, and reliability of the operation of the nuclear reactor. In this work, vacuum diffusion bonding of Zr-4 alloy was studied at the diffusion temperature ranging from 760 to 820 °C with holding times of 30–90 min. The effects of diffusion bonding temperature and holding time on the interfacial microstructure and mechanical properties of the diffusion bonded Zr-4 alloy joints were investigated in detail, and the relationship between the interfacial microstructure and shear strength of the diffusion bonded joints was discussed. The results show that the interface bonding ratio of the diffusion bonded Zr-4 joint gradually increased from 74% to 95% with the increasing of bonding temperature. In addition, the grain size of the base material became a larger and brittle second phase composed of Zr(Cr, Fe)2 and eutectic α-Zr + Zr(Fe, Cr)2 formed in the joint with the increase of the temperature as well as the extension of the bonding time. The highest shear strength of 349 MPa was obtained at 800 °C for 30 min under 7 MPa, and the crack of the joint was primarily propagated along with the base material rather than the bonded interface.

scholarly journals Diffusion Bonding of Ti2AlNb Alloy and High-Nb-Containing TiAl Alloy: Interfacial Microstructure and Mechanical Properties

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1061 ◽  
Author(s):  
Hong Bian ◽  
Yuzhen Lei ◽  
Wei Fu ◽  
Shengpeng Hu ◽  
Xiaoguo Song ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Diffusion Bonding ◽  
Tial Alloy ◽  
Energy Dispersive Spectrometer ◽  
Bonding Temperature ◽  
Interfacial Microstructure ◽  
Holding Time ◽  
Interfacial Structure ◽  
Microstructure And Mechanical Properties ◽  
O Phase

In this study, reliable Ti2AlNb/high-Nb-containing TiAl alloy (TAN) joints were achieved by diffusion bonding. The effects of bonding temperature and holding time on the interfacial microstructure and mechanical properties were fully investigated. The interfacial structure of joints bonded at various temperatures and holding times was characterized by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and X-ray diffraction (XRD). The results show that the typical microstructure of the Ti2AlNb substrate/O phase/Al(Nb,Ti)2 + Ti3Al/Ti3Al/TAN substrate was obtained at 970 °C for 60 min under a pressure of 5 MPa. The formation of the O phase was earlier than the Al(Nb,Ti)2 phase when bonding temperature was relatively low. When bonding temperature was high enough, the Al(Nb,Ti)2 phase appeared earlier than the O phase. With the increase of bonding temperature and holding time, the Al(Nb,Ti)2 phase decomposed gradually. As the same time, continuous O phase layers became discontinuous and the Ti3Al phase coarsened. The maximum bonding strength of 66.1 MPa was achieved at 970 °C for 120 min.

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