Superposition method for welding ceramic and aluminum

Abstract

The invention discloses a superposition method for welding ceramic and aluminum. The method comprises the following steps of: tinning an aluminum plate, removing oil by using organic solvents such as kerosene, gasoline and the like roughly before tinning, performing alkaline washing by using mixed liquid of sodium hydroxide and sodium carbonate, and electroplating in a mixture of stannous sulfate, sulfuric acid and the like, so that a tin layer is formed on the surface of the aluminum; manufacturing a template, coating a photosensitive adhesive on a screen mesh, placing the template on the screen mesh, performing exposure, washing an unexposed part by using water, performing screen printing on a ceramic substrate by using silver paste, printing the silver paste on the ceramic substrate, conveying the ceramic substrate to a ceramic sintering furnace, and sintering at a high temperature, so that a silver foil forms a circuit and combines with the ceramic tightly by ceramic sintering, wherein an aluminum oxide ceramic substrate is used as the ceramic substrate; and performing reflux welding on the ceramic with the silver foil and the tinned aluminum according to the superposition sequence of the ceramic and the aluminum. By the method, metal and nonmetal are fixed tightly, namely the advantages of the aluminum and the ceramic are combined, so the method has practical significance.

Description

technical field [0001] The invention relates to the technical field of material processing, in particular to a method for mutual welding of metal and nonmetal. Background technique [0002] With the demand for high-end technology in the country, especially the development of the aerospace industry, there are various high-level requirements for the performance of materials. Some requirements are not only high thermal conductivity, corrosion resistance, wear resistance, but also insulation and cutting processing. Ceramics and aluminum can only meet some of the requirements. At present, only the close combination of metal materials and non-metal materials can meet the requirements. The tight compound can only be ideal for welding, because welding is to form a permanent connection by heating, pressurizing or heating two parts of homogeneous or non-homogeneous materials, using the connection between atoms and the diffusion of particles. , so as to ensure the requirements of it...

AI Technical Summary

Problems solved by technology

However, due to the obvious differences between ceramics and metals in terms of electronic teaming crystal structure, mechanical properties, thermophysical properties and chemical properties, it is difficult to realize the combination of ceramics and metals; it is almost impossible to obtain with conventional welding materials and processes. Reliable connection, because the bonding mechanism of the ceramic and metal interface is chemical bonding

In addition, due to the large difference in thermal expansion coefficient between ceramics and metals, a large thermal stress will be generated after cooling down from the welding temperature, which will reduce the strength of the welding joint, and will deform if it is light, and crack if it is severe. Metal welding is a difficult problem

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