| 摘要 |
PURPOSE:To execute brazing of titanium and a titanium alloy at a low melting point, and also to improve the brazing strength by limiting a component composition of a palladium brazing filler metal. CONSTITUTION:A palladium brazing filler metal is constituted of 5-30% silver, 0.25- 7% silicon, total 0.5-20% at least one kind of gallium and germanium by a weight ratio, and palladium as the balance. In this regard, the reason why the component composition is limited is because the melting point is lowered, as for silver, and if the composition is under the limit, the melting point does not fall so mush, and if it exceeds the limit, a joint strength becomes low. Next, silicon is used in order to lower the melting point and to improve the fluidity, and if it is under the limit, the fluidity and a fall of the melting point cannot be expected, and if it exceeds, a brazing material cannot be worked to a plate, a wire, etc. Next, gallium and germanium lowers the melting point, reduces a diffusion of a base metal into a brazing metal, and prevents silver from being melted and divided, and if it is under the limit, there is no said effect, and if it exceeds the limit, working of the brazing material becomes difficult. Also, palladium has a good wettability with respect to titanium, a titanium alloy, iron, copper and nickel, and has a corrosion resistance, therefore, it is an indispensable element. |
