Fiber-reinforced Cf/SiC composite material welded joint

Abstract

The invention discloses a fiber-reinforced Cf / SiC composite material welded joint and belongs to the field of connection of composite materials and heterogeneous metals. A carbon fiber reinforced phase on the surface of the joint disclosed by the invention is 500-1500[mu] m. The joint is prepared by the following steps: placing a Cf / SiC composite material in a NaOH solution, performing heating corrosion, performing ultrasonic cleaning, and drying the material for later use; setting a scanning speed, a scanned surface distance and laser power in software, and processing the material so as to obtain a final product. The welded joint disclosed by the invention adopts a carbon fiber reinforced structure, the carbon fiber reinforced phase exists between the Cf / SiC composite material and the metal welded joint, the carbon fiber reinforced phase at the joint is one part of a fiber woven inside the Cf / SiC composite material, the carbon fiber reinforced phase at the joint and the metal solder are wetted, the carbon fiber reinforced phase is connected with the composite material and the metal solder, and by virtue of a fiber toughening effect and a pullout effect, the purpose of toughening the welded joint is achieved.

Description

technical field [0001] The invention relates to a fiber-reinforced Cf / SiC composite material welded joint, which belongs to the field of connection between composite materials and heterogeneous metals. Background technique [0002] From the application point of view, at present, all major countries in the world attach great importance to the development of anti-missile and other advanced defense weapons. The United States regards the development and configuration of missile defense systems as a major national policy, and my country has also carried out advanced research on advanced kinetic energy interceptors. The thrust chamber as a power system (such as missile engine thrust chamber, anti-missile missile attitude control thrust chamber, etc.) is made of light weight, high specific strength, high temperature resistant C / SiC (that is, carbon fiber reinforced silicon carbide) composite material. After more than ten years of research and development since the "Ninth Five-Year ...

AI Technical Summary

Problems solved by technology

In many applications, it is often necessary to connect Cf / SiC composite materials and metal materials to achieve the purpose of complementary advantages, but conventional methods such as active metal brazing, solid-phase diffusion connection, and instantaneous liquid-phase connection have low connection strength, The interface reaction is difficult to control, the interface forms a brittle phase, the interface stress is large, and the thermal expansion does not match the problems that need to be solved urgently.

[0004] The welded joint structures obtained by the above connection methods are all in two-phase surface contact, and there is no fiber toughening, so the fracture is a brittle fracture mechanism, and there is no yield stage in the stress-strain curve. The consequences of this in application are often is catastrophic, without any warning of strain, suddenly and completely ruptures

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