Microstructure and mechanical properties of vacuum electron beam welded joints of Ti/Cu dissimilar metals

Zhou, Jie; Guo, Shun; Duan, Mengwei; Peng, Yong; Gu, Jiande; Zhou, Qi; Wang, Kehong

doi:10.1016/j.vacuum.2023.112451

Cited by 4 publications

(1 citation statement)

References 28 publications

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“…The joining of titanium (Ti) with dissimilar materials such as stainless steel and copper (Cu) is of great technological significance owing to widespread application of such hybrid components in various engineering sections, ranging from Ti sputtering target manufacturing to the heat exchanger fabrication specific to nuclear power generation industry [1][2][3][4]. It has been long recognized to be a challenging task to achieve strong and reliable dissimilar joining of Ti and Cu, primarily because of poor metallurgical compatibility and notable mismatch in physical properties of Ti/Cu system [5,6]. There is very limited mutual solubility between Ti and Cu.…”

Section: Introductionmentioning

confidence: 99%

Improving bonding strength and reliability of brazed titanium/copper dissimilar joint using vanadium interlayer

Mengen,

2023

Mater. Res. Express

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Conventional practice of brazing titanium (Ti) to copper (Cu) using Ag-28Cu eutectic filler alloy is of limited success because of the generation of brittle Ti-Cu intermetallic compounds (IMCs). The bonding strength is unsatisfactory owing to embrittlement of IMCs, and it is difficult to reproduce the bonding strength as the joint microstructure is highly sensitive to brazing parameters. In the current study, it was demonstrated that the formation of such undesirable IMCs can be suppressed and strong Ti/Cu joint can be obtained by brazing at 850 °C using a refractory vanadium (V) interlayer 15 μm in thickness deposited on Ti substrate, in combination with an Ag-Cu-Ti active filler alloy. The V interlayer successfully blocked the interaction between Ti and filler alloy. Bonding mechanisms of the resultant joint can be deduced to be a synergy of active brazing in the V/Ag-Cu-Ti/Cu half and solid-state diffusion bonding at the Ti/V interface. The thus developed joint was comprised of continuous Ti-V solid solution, unconsumed V interlayer and remaining filler alloy. Attributed to elimination of brittle IMCs at joint interface, excellent bonding strength of ∼220 MPa which is comparable with strength of Cu base metal was achieved. Moreover, since the joint evolution was dominated by sluggish solid-state diffusion at the Ti/V interface and very limited erosion of V interlayer by the Ag-Cu-Ti filler, desirable IMC free joint can be obtained over a wide range of brazing time (2 ∼ 5 min), enabling outstanding reliability of the high bonding strength.

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