Brazing method for silicon carbide ceramics

Abstract

The invention discloses a brazing method for silicon carbide ceramics. The brazing method comprises the following steps: carrying out surface treatment on the silicon carbide ceramics; depositing a first metal layer on the surface of the silicon carbide ceramics by adopting a vapor deposition method, and then depositing a second metal layer on the surface of the first metal layer to obtain the silicon carbide ceramics deposited with double metal layers, wherein the material of the first metal layer is selected from one of Ni, Ti, Fe or Zr, and material of the second metal layer is selected from Al; placing the silicon carbide ceramics needing to be connected in a vacuum sintering furnace, then placing a pure Al foil between the silicon carbide ceramics needing to be connected, starting heating when vacuum in the furnace reaches 10 <-1 > Pa, increasing the temperature to 600-800 DEG C, and conducting heat preservation for 10-60 min; and after heat preservation is finished, performing cooling to room temperature along with the furnace to obtain the silicon carbide ceramics subjected to brazing connection. According to the brazing method for the silicon carbide ceramics, the wettability of aluminum-based brazing filler metal to the silicon carbide material can be improved, the brazing temperature can be reduced, and the bonding strength of a brazed joint can be improved.

Description

technical field [0001] The invention relates to the technical field of brazing of silicon carbide ceramics, in particular to a brazing method of silicon carbide ceramics. Background technique [0002] Silicon carbide ceramics have many excellent properties such as high temperature resistance, wear resistance, good thermal conductivity, excellent corrosion resistance and high mechanical strength, and have broad application prospects in the fields of nuclear industry, aerospace, military industry, automobile industry and electronics industry. At present, the connection methods of silicon carbide ceramics mainly include mechanical connection, bonding, active metal diffusion welding and metal brazing. Advantages become an important way of connection between silicon carbide ceramics. [0003] Due to the poor wettability of metal aluminum liquid to the surface of silicon carbide ceramics, the bonding strength of the brazing joint of aluminum brazing silicon carbide ceramics is lo...

AI Technical Summary

Problems solved by technology

[0003] Due to the poor wettability of metal aluminum liquid to the surface of silicon carbide ceramics, the bonding strength of the brazing joint of aluminum brazing silicon carbide ceramics is low, and increasing the brazing temperature will intensify the reaction between aluminum and silicon carbide ceramics, resulting in brittleness. Reactive phase Al 4 C 3 corrosion of the ceramic substrate

The traditional method of improving aluminum brazing is mainly to add active elements such as Si and Mg to Al-based solder, which can inhibit the interface chemical reaction between aluminum and silicon carbide to a certain extent, but the improvement of wettability is not obvious.

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