Design method for annular structural member diffusion bonding fixture

Abstract

The invention discloses a design method for an annular structural member diffusion bonding fixture. A proper fixture material is selected, and a fixture is guaranteed to be safely used while an expansion pressure difference which is large enough is provided. In order to guarantee to generate even and stable connection pressure on a connection interface, a fixture structure and an annular member structure are corresponded, and detail characteristics are similarly matched; the inner wall of the fixture is in complete contact with the outer surface of a connection member as far as possible; and the outer wall of the fixture is convenient in manufacture, saves cost and is designed to be regular cylindrical surface. The coefficient of thermal expansion of an annular fixture manufacture materialis reasonably selected, since the expansion coefficient of the fixture material and the expansion coefficient of specimen alloy are similar in a cooling process, a cooling shrinking difference is small, and an influence on a connection interface is small. By use of the technical scheme of the invention, the successful connection of TiAl alloy and Ti2AlNb alloy is realized, and a reference is provided for the diffusion bonding of other annular structural members with a large outer layer metal expansion coefficient.

Description

technical field [0001] The invention relates to the field of solid-state welding, in particular to a design method of a fixture suitable for the diffusion connection of annular structural parts of dissimilar intermetallic compounds with large expansion coefficients of outer metals. Background technique [0002] Ti-Al intermetallic compounds have the characteristics of low density, high specific strength and good oxidation resistance. They are ideal lightweight high-temperature metal structural materials and have broad application prospects in the fields of aero-engines and aerospace vehicles. Among them, the service temperature of TiAl alloy can reach 700-900 ° C, Ti 2 The use temperature of AlNb alloy can reach 650℃. However, Ti-Al alloys are inherently brittle and difficult to process, which limits their applications. Diffusion bonding is an important method to realize the forming of complex intermetallic compounds, so the research and development of TiAl / Ti 2 AlNb allo...

AI Technical Summary

Problems solved by technology

This method needs to make the whole blisk sheath and vacuum-fill superalloy powder and then perform hot isostatic pressing, which is a complex process.

[0006] Currently, for TiAl alloys and Ti 2 The research on diffusion bonding of AlNb alloy rings is not deep enough, and there are few related reports

Moreover, the expansion coefficient of the outer metal TiAl alloy is large, and the expansion pressure difference cannot be obtained by conventional methods. If a rigid constraint is imposed on the boundary for thermal self-pressure diffusion connection, it is easy to generate a large residual stress

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