Silicon carbide granules reinforced aluminium base composite material connection method

Abstract

The present invention relates to the connection method of SiC particle reinforced Al-base composite material (SiCp/Al), and is especially instantaneous liquid phase diffusion connecting technology of SiCp/Al. The present invention realizes the metallurgical combination between samples with mixed Al, Ag, Cu and Ti powder as the intermediate layer, and through the ternary eutectic reaction of Al, Ag and Cu and certain time of component diffusion and homogenization. The technological process includes compounding the intermediate layer, surface treatment of the mother material to be connected, setting the mixed powder slurry compounded with anhydrous alcohol to the surface of the mother material, heating in vacuum furnace for certain time and cooling in the furnace. The said process can connect SiCp/Al parts with complicated structure and has the features of low connection temperature, less damage to mother material, etc.

Description

technical field [0001] The invention belongs to the category of material connection technology, and particularly relates to the instantaneous liquid phase diffusion connection technology of silicon carbide particle reinforced aluminum matrix composite materials. Background technique [0002] SiC particle reinforced aluminum matrix composites (SiCp / Al) have excellent physical and mechanical properties, such as high specific strength, high specific modulus, low expansion coefficient, wear resistance, high temperature resistance, good thermal stability, etc., in aerospace , automotive, electronics, medical and other fields have extremely high application value, and are ideal structural materials in the field of space technology. [0003] With the application and promotion of SiCp / Al composite materials, the problem of its connection with itself or other materials has attracted more and more attention. At present, although there are some studies on the connection of SiCp / Al com...

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Problems solved by technology

In the 1999 Harbin Institute of Technology Journal No. 2, pages 130-133, it was introduced that the main problems of connecting SiCp / Al composite materials by high-temperature fusion welding are: (1) the reinforcing phase (SiC) and the matrix metal (Al) in the weld pool ) react to form brittle compounds (Al 3 C 4 ), which seriously affects the mechanical properties of the weld and the base metal; (2) due to the high melting point SiC reinforcement phase, the molten pool has high viscosity and poor fluidity during fusion welding, resulting in difficult welding operations, poor weld formation, and prone to pinching Defects such as slag, pores and SiCp segregation

In 1997, 76: 92 Welding Journal pointed out that it is difficult to obtain satisfactory results for SiCp / Al composite materials by brazing. The main reasons are: (1) Brazing is limited by the performance of solder The joint strength is low; (2) Al on the surface of the solder and the brazing sample 2 o 3 The oxide film seriously affects the wetting and spreading of the solder on the surface of the base metal

In July 2002, Volume 32, No. 3 "Research Progress in Diffusion Bonding of Particle-Reinforced Aluminum Matrix Composite Materials", it was stated that direct solid-phase diffusion welding as a solid-phase bonding method can overcome the problems of fusion welding to a certain extent, but solid-phase diffusion The connection of aluminum matrix composite materials needs to be completed under the conditions of high temperature and high pressure, which will inevitably cause excessive plastic deformation of the connected parts

However, metal foil as an intermediate reaction interlayer has limitations in the connection structure, which is not conducive to the connection of complex components, and the eutectic reaction temperature of Al-Cu and Al-Ag is relatively high (Al-Cu eutectic temperature 548 ° C and Al-Ag eutectic temperature (566°C) is also easy to damage the base material, so there are still many problems in using Cu and Ag metal foils as intermediate reaction interlayers to connect SiCp / Al composite materials by reaction diffusion

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