Study of a novel brazing process for W-W joints in fusion applications. (15th December 2016)

• Record Type: Journal Article
• Authors: de Prado, J.; Sánchez, M.; Utrilla, M.V.; López, M.D.; Ureña, A.
• Is Part Of: Materials & design. Volume 112(2016)
• Page Start: 117
• Page End: 123
• Publication Date: 2016-12-15
• Subjects: Tungsten -- Brazing -- Fusion reactor -- Joining -- Plasma facing component; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2016.09.067
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: Next generation of fusion power plants needs to develop joining technologies for several components of the reactor. In this paper, a novel brazing process for joining two pieces of divertor component made of tungsten is proposed. A flexible tape, fabricated of a mixture of 86Fe-14Ti metallic powders and an organic binder, has been used as filler material. Different binder contents (from 5 up to 30 wt.%), which provides the required flexibility to the filler tape for its fitting to the divertor curved surface, have been evaluated. The proposed flexible filler tape will improve the brazing procedure, but also it could be implemented for any curved component of the power generation industry. Two fillers contents (95/5 and 90/10 powder/binder ratios) have been used for brazing tests that were carried out in a high vacuum furnace at 1350 °C for 10 min. W-W brazed joints exhibited high continuity along the joint and no wetting problems were detected. The microhardness tests gave rise to similar values and revealed that the mechanical properties of tungsten base material were not modified during the brazing cycle. The shear strength of the joints (~ 44 MPa) meets the mechanical requirements of the component. Graphical abstract: Highlights: New brazing process mixing pure metallic powders with an organic binder is proposed. The binder provides adequate physical and metallurgical adaptation capabilities to the parent material surfaces. The flexible capabilities of the manufactured filler tapes allow complex component shape to braze. The selected metallic composition gives rise to high continuous W-W joints for fusion application.