Method for preparing sandwich brazing filler metal for brazing ceramic-based composite materials and nickel-based high-temperature alloys

Abstract

The present invention discloses a method for preparing a sandwich brazing filler metal for brazing ceramic-based composite materials and nickel-based high-temperature alloys. The sandwich brazing filler metal is composed of a composite of three layers of alloy: AgCu brazing filler metal, high entropy brazing filler metal, and AgCu brazing filler metal. The high entropy brazing filler metal is located between the two layers of AgCu brazing filler metal. The chemical formula of the high entropy brazing filler metal is NiCrVSiMnCu. x ,NiCrVSiMnCu x The value range of x is 0 to 0.5, wherein the molar ratio of Ni, Cr, V, Si, Mn, and Cu is 1:1:1:1:1:0 to 0.5. The raw materials are ultrasonically cleaned and dried, and are stacked in the order of Ag-28Cu solder, high entropy solder, and Ag-28Cu solder, and then placed in a vacuum brazing diffusion welding furnace for diffusion welding to obtain a composite solder alloy. The composite solder alloy is then annealed, cold rolled, cut, and surface cleaned and polished to prepare a sandwich solder alloy foil. The present invention adopts the above-mentioned sandwich solder preparation method to solve the problem of metal-based solder in SiC f It can solve the problem of poor wettability of the welding surface of SiC composite materials and effectively inhibit the formation of brittle metal compounds, thereby improving the shear strength of the welded joint.

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