A Ti-Fe-Sn thin film assembly for joining tungsten and reduced activation ferritic-martensitic steels

Publication date: 5 July 2017
Source:Materials & Design, Volume 125
Author(s): Wen Zhu, Jianbing Qiang, Yingmin Wang, Jizhong Sun, Jianbao Wang, Youyun Lian, Fan Feng, Xiang Liu
The effective joining of tungsten and reduced activation ferritic-martensitic (RAFM) steels is crucial to fabrication of the divertor components of fusion reactors. In the present work, a low neutron-activation filler metal system of Ti-Fe-Sn was designed to realize the so-called exothermic-reaction-assisted brazing. A series of three-layered Ti-Fe-Sn thin film assemblies were made by electroplating, which allowed the brazing of tungsten with a CLF-1 RAFM steel to be carried out at a temperature as low as 1090°C. The joint structures made from the Sn-bearing filler metals demonstrated high strength and high resistance against thermocycling. The Sn-film layer in the filler assembly has delivered favorable alloying effects on depressing separation of Ti element in the W grain boundaries and the formation of pores, and on microstructure refinement in the brazed joints as well.

Graphical abstract

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