the induction coil is a dual rotation coil with radius 22mm and pitch 11.33mm manufactured by copper tube with diameter 8mm, thickness 1.0mm. The vacuum chamber was manufactured by AISI 304L plate with thickness 10mm to sustain against the vacuum pressure over than lxlO-3 Torr, as SFA-S.31 specification for fluxes for brazing and braze welding, which is the design criteria for the Ni (BNi, BNi-2) brazing. A purging gas supply device and a vacuum exhaust device were connected to the vacuum chamber to minimize the remaining oxygen inside of the chamber at the state of vacuum exhaust