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

摘要

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 presentwork, a lowneutron-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 degrees 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. (C) 2017 Elsevier Ltd. All rights reserved.