Diffusion bonding method of silicon carbide ceramics and ferritic stainless steel

Abstract

The invention relates to a diffusion bonding method of silicon carbide ceramics and ferritic stainless steel. Al-Si intermediate alloy is added between the contact faces, to be connected, of the silicon carbide ceramics and stainless steel, and the silicon carbide ceramics and a ferritic stainless steel plate workpiece to be connected are tightly pressed through an upper pressing head and a lower pressing head of diffusion bonding equipment, are arranged in a vacuum chamber and are connected in a diffusion bonding mode. According to technological parameters, heating temperature is 500 DEG C to 540 DEG C, heat preservation time is 25min to 50min, pressure is 40MPa to 90MPa, and a vacuum degree is 1.33 *10-3Pa to 1.33*10-2Pa. Then cooling, cleaning and drying are carried out to achieve diffusion bonding. The Al-Si alloy foil is added, a transition liquid phase is formed on a contact surface in a diffusion bonding process, and the diffusion bonding of the silicon carbide ceramics and the stainless steel is achieved. The melting temperature of the Al-Si alloy foil is greatly lower than the softening temperature of the ferritic stainless steel, and the method is beneficial for accelerating a silicon carbide ceramics / stainless steel interface to form good diffusion bonding.

Description

technical field [0001] The invention relates to a diffusion connection method of ceramics and stainless steel, in particular to a method for diffusion connection of silicon carbide ceramics and ferritic stainless steel by adding an intermediate alloy, which belongs to the field of welding technology. Background technique [0002] Ceramics are hard and brittle high-melting materials with low thermal conductivity, good chemical and thermal stability, high compressive strength and unique properties, such as insulation and electricity, magnetism, sound, light, heat and Biocompatibility, etc., are increasingly valued by people. Due to the inherent brittleness of ceramic materials and the difficulty of preparing high-performance components, the composite structure prepared by connecting ceramics and stainless steel has broad application prospects in the fields of energy, chemical industry, electronics, machinery, and aerospace. [0003] At present, brazing methods are mainly used...

AI Technical Summary

Problems solved by technology

Due to the impact of welding costs, the application of brazing silicon carbide ceramics and stainless steel with precious metal brazing filler metals is greatly limited

[0004] Existing diffusion bonding methods mostly use precious metals as intermediate alloys, and the temperature is relatively high, which not only has high cost, but also is not conducive to diffusion reactions.