A method for auxiliary brazing of low-expansion flexible intermediate layer

Abstract

The invention relates to an auxiliary brazing method of a low-expansion flexible intermediate layer, which relates to an auxiliary brazing method of an intermediate layer, and aims at solving the problems that the residual stress of a brazing connector is excessively large, the introduction amount of a ceramic reinforcing phase is small and the brittleness of a weld is worsened due to the great difference between the ceramic heat expansion coefficient and the metal heat expansion coefficient in the prior art. The method comprises the following steps: I, ball milling and mixing the measured negative-heat-expansion coefficient powder and coupling agent powder, then vacuum annealing to obtain annealed mixed powder, mixing the annealed mixed powder and measured metal matrix powder, hot pressing and sintering to obtain a low-expansion flexible intermediate layer; and II, successively laminating to-be-welded ceramic, a brazing filler metal foil, the low-expansion flexible intermediate layer,the brazing filler metal foil and to-be-welded metal, brazing the ceramic / brazing filler metal foil / low-expansion flexible intermediate layer / brazing filler metal foil / metal in a vacuum furnace, andcooling along with the furnace. The auxiliary brazing method disclosed by the invention is used for the auxiliary brazing of the low-expansion flexible intermediate layer.

Description

technical field [0001] The invention relates to a method for interlayer auxiliary brazing. Background technique [0002] Ceramic materials are engineering materials with the highest hardness, excellent dimensional stability, ablation resistance, impact resistance and good wave transparency. They can be widely used in the manufacture of key components such as heat resistance and corrosion resistance in the aerospace field. Its extremely low density can reduce the weight of the matrix and is a potential lightweight material. However, due to its high brittleness, it is difficult to machine and form complex structures, and it is only used in key parts. It usually needs to be connected with the metal substrate to meet the actual application requirements. Among the many connection methods, brazing is widely used in the connection of ceramics and metals because of its simple process, low cost and mass production. It is usually connected with a solder containing active elements tha...

AI Technical Summary

Problems solved by technology

[0004] The present invention aims to solve the problems of excessive residual stress of brazed joints caused by the large difference in thermal expansion coefficient between ceramics and metals, the introduction of ceramic reinforcement phase is small, and the brittleness of weld seams is aggravated, and a low-expansion flexible intermediate layer auxiliary brazing method

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