| 摘要 |
PURPOSE:To efficiently generate Zn vapor and to enable coating with the Zn vapor and diffusion of Zn simultaneously with brazing by specifying the amt. of molten Zn, the surface area of the molten Zn, the flow rate of gaseous N2 and the atmosphere in a heating furnace in accordance with the internal volume of the furnace. CONSTITUTION:When Zn is put in a heating furnace and the surface of an Al member is enriched with Zn during NB brazing, the put Zn and the atmosphere in the furnace are heated to >=430 deg.C to melt the Zn and to generate Zn vapor. When the internal volume of the heating furnace is considered to be Vl, the amt. of molten Zn is regulated to 1-10g/l, the surface area of the molten Zn to 0.05-2.5cm<2>/l and the flow rate of gaseous N2 as a carrier gas to 0.05V-Vl/min. The dew point of the atmosphere in the furnace under nearly atmospheric pressure is kept at <=-20 deg.C and the concn. of oxygen in the atmosphere at >=1,000ppm. Zn vapor is easily generated and diffusion of Zn as well as NB brazing is facilitated. |
