Investigation of contact phenomena at cubic boron nitride-filler metal interface during electron beam brazing

• Published in: Diamond and related materials 1997-05, Vol.6 (8), p.1067-1070
• Main Authors: Pobol, Igor L., Shipko, Alexey A., Nesteruk, Irina G.
• Format: Article
• Language: English
• Subjects: Applied sciences; Boron nitride; Condensed matter: structure, mechanical and thermal properties; Contact phenomena; Electron beam brazing; Exact sciences and technology; Filler metal; Metals. Metallurgy; Physics; Solid-fluid interfaces; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Wetting
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/S0925-9635(97)00002-2

The physical and chemical processes which occur at the cubic boron nitride (CBN)-filler metal interface during electron beam brazing are investigated. Contact angles of wettability of multicomponent adhesion-active Cu-based alloys on CBN and steel are determined. The distribution of chemical elements at the CBN-brazing filler metal interface was investigated using an electron microscope and electron probe microanalyser. The titanium concentration is found to abruptly enhance at the interface as against the content of this element in a brazing filler metal, and Ti and Cu diffuse in a superhard material. A mutual diffusion of solid and liquid phase components results in the formation of a narrow transition layer 2–3 μm thick that consists of titanium-boron compounds and solid solutions. A qualitative elemental composition is analysed for structure components at different brazing alloy zones. It is established that a phase containing up to 62 wt.% Ti can be formed near a CBN- brazing filler metal interface during an electron beam brazing.