Flexible composite middle layer brazing alloy and method of utilizing brazing ceramic and metal

Abstract

The invention discloses flexible composite middle layer brazing alloy and a method of utilizing brazing ceramic and metal, and relates to the composite brazing alloy and the method of utilizing the brazing ceramic and metal. The flexible composite middle layer brazing alloy and the method aim at solving the problems that the conventional method is high in cost and the forming of brittle compound of a joint can not be restrained. The flexible composite middle layer brazing alloy is prepared from upper layer brazing alloy, a flexible middle layer and lower layer brazing alloy. The brazing method comprises the steps of: cleaning greasy dirt and impurity on a pre-welding surface; processing the upper-layer brazing alloy, the flexible middle layer and the lower-layer brazing alloy into small sheets; and ultrasonically cleaning and airing ceramic to be welded, metal to be welded, the upper layer brazing alloy, the flexible middle layer and the lower layer brazing alloy by acetone, assembling a workpiece to be welded, and putting the workpiece to be welded into a vacuum heating furnace to braze. According to the method disclosed by the invention, the operation is simple; the residual stress of the joint is released by adding the flexible middle layer; and the forming of the brittle compound of the joint is restrained, and the shearing strength of the joint is improved by 30-109%. The method disclosed by the invention is used for brazing the ceramic and the metal.

Description

technical field [0001] The invention relates to a composite brazing filler metal and a method for brazing ceramics and metals using it. Background technique [0002] Ceramic materials have the advantages of low density, high specific strength, high temperature resistance, and stable chemical properties at high temperatures. However, ceramic materials have poor plasticity and are difficult to prepare components with complex shapes. Using brazing technology to prepare ceramic and metal composite components can not only take advantage of the excellent high-temperature performance of ceramic materials, but also give full play to the plasticity and toughness of metal materials to meet the needs of modern engineering applications. However, the physical and chemical properties of ceramics and metals are quite different, especially the difference in thermal expansion coefficient between the two will generate a large residual stress at the brazed joint interface, which will weaken th...

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Problems solved by technology

[0004] The present invention solves the problem that the existing method for relieving the residual stress of the joint needs to be remanufactured on the basis of the original commercial solder, which increases the cost and cannot suppress the formation of brittle compounds in the joint, and provides a soft composite intermediate layer solder and A method of brazing ceramics and metals using it

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