Preparation method for Nb-Si base ultra-temperature alloy turbine vane

Abstract

The invention belongs to the technical field of the turbine blade manufacturing, and particularly relates to a method for preparing an Nb-Si base ultra-temperature alloy turbine vane by the electron beam melting (EBM). Electron beam selection area high-speed forming equipment is utilized, and the preparation of the complex Nb-Si alloy turbine vane is directly finished in one step by a CAD (computer-aided design) model by setting a reasonable technological parameter; the obtained turbine vane has the advantages of high consistency, good forming precision and few defects; the alloy vane mainly consists of Nbss sosoloid and Nb5Si3 phase, so that the alloy vane has a small phase size and even distribution, and the combination property of the turbine vane can be improved. According to the method, no dies are required in the turbine vane forming process, alloy pollution and oxidation can be reduced, inclusion content is lowered, the alloy material use ratio is high, and the combination property of the vane can be improved.

Description

technical field [0001] The invention belongs to the technical field of manufacturing turbine blades, and in particular relates to a method for preparing a Nb-Si-based ultra-high temperature alloy turbine blade. Background technique [0002] The development of high-performance aircraft depends on the continuous progress of aero-engine technology. As the thrust-to-weight ratio and efficiency of gas turbine engines increase, the turbine inlet temperature continues to increase. Among gas turbine engine components, the working conditions of the turbine blades are the most severe, not only to withstand extreme high temperature, high stress and harsh corrosion environment, but also require a long service life, which requires the turbine blade material to have high creep resistance, Good corrosion resistance, high high temperature durable strength and fracture toughness, etc. [0003] At present, the third-generation nickel-based single-crystal superalloy used in aero-engine turbi...

AI Technical Summary

Problems solved by technology

Nb-Si-based alloys prepared by vacuum arc melting have uncontrollable microstructure uniformity and a large number of shrinkage cavities, which affect the properties of the alloy.

The preparation of Nb-Si based alloy by vacuum induction melting can keep the alloy composition uniform, but the melt temperature is not uniform during the preparation process, the degree of superheat is low, and it is easy to cause defects such as insufficient casting

Directional solidification can obtain a structure with good comprehensive properties, has the characteristics of near-network forming and high efficiency, and has become the preferred method for preparing Nb-Si-based alloys. The amount and inclusions increase, reducing the performance of the alloy

The technology of preparing Nb-Si alloys by investment casting has not been fully developed, and the activity of molten Nb-Si-based alloys limits the application of ceramic-based mold shell systems

[0005] Not only that, the turbine blade structure is extremely complex (attached figure 1 ), using the above method to prepare blades needs to prepare complex molds or formwork, the process is cumbersome, and many post-processing procedures are required at the same time, and the production efficiency is low

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