Liquid Metal Formation on Ni / B / Ni Diffusion Bonded Joint - Liquid Phase Diffusion Bonding Using B as an Insert Material (3) -
정재필J . P . Jung, 강춘식C . S . Kang
Abstract
The mechanisms of the liquid metal formation at Ni/B/Ni (Ni: base metal, B: insert material) joint, which could be characterized as liquid phase diffusion bonding, has been investigated. Fine boron (B) powders (under 300 mesh) were coated on the elaborately polished bonding surfaces as an insert material. The specimen packed in quartz tube under 5×10^(-3) torr vacuum was heated in a induction furnace to 1283K-1473K. It is observed that inserted material B was diffused into base metal, and that liquid metal was formed by the reaction of B and Ni. Liquid metal was formed preferentially at the grain boundaries. The state of phases was analyzed to depend on B content because of the fact that content of B on the liquid layer was higher than the solid state base metal.