Discharge plasma diffusion welding manufacture method for Laval nozzles

Abstract

The invention relates to a discharge plasma diffusion welding manufacture method for Laval nozzles and belongs to the welding field. The method comprises the steps of (1) blanking, (2) machine shaping, wherein the welding position roughness <= 1.6 micrometers; (3) chemical degreasing and surface oxide removing; (4) drying, which is performed in a drying box of an air blower; (5) assembly; (6) discharge plasma diffusion welding; (7) finish turning. The method has the advantages that the process problem of discharge plasma diffusion welding of or Laval nozzle components is solved, and a positive role is played in the promotion and application of the diffusion welding of the Laval nozzle components in spacecrafts; the welded rate is high, and the joint strength is identical to the strength of base materials; the member deformation is small, the size accuracy is high, and product design requirements can be met; the method is free of environmental pollution and capable of being automated easily.

Description

technical field [0001] The invention relates to a manufacturing method of a Laval tube, in particular to a manufacturing method of a Laval tube discharge plasma diffusion welding for an aircraft. Background technique [0002] The Laval tube, also known as the nozzle or zoom tube, has a contracted-expanded inner cavity of a certain shape. The high-pressure gas flowing through the Laval tube will form a stable laminar flow after contraction and expansion, and the flow rate can reach supersonic speed. Generally, small-diameter Laval tubes can be integrally formed, and for large-diameter Laval tubes used in aircraft, due to high operating temperature and large diameter, it is necessary to lay a layer of copper with axial groove 4 on the inner surface of the Laval tube. Quality water cooling jacket 3 (such as figure 1 , 2 shown). [0003] At present, the manufacturing method of the above-mentioned Laval tube mainly adopts three methods: one is to generate the Laval tube matrix...

AI Technical Summary

Problems solved by technology

The pre-processed outer tube 1, convex tube 2 and water cooling jacket 3 are welded by vacuum brazing, electron beam welding and other methods. The welding strength between the inner and outer walls of the Laval tube manufactured by this welding method is low , the welding rate is poor, and the brazing method is also easy to block the water tank 4

The third is to use diffusion welding to apply diffusion welding pressure and temperature to the welding surface under vacuum conditions, so as to realize the joint welding between the joint surfaces. This method has high requirements for the preparation of the surface of the weldment to be welded. Parts implement mutual diffusion between atoms, requiring fine surface processing and cleaning, long welding cycle, long time heat preservation and pressure holding to achieve high welding rate, and the amount of deformation is not easy to control, which is easy to cause the diameter direction of Laval tube large deformation

However, no applicable method has been developed for a long time, and this is obviously a problem that the relevant industry is eager to solve

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