Superfine column crystal high-temperature alloy blade and laser directional solidification preparation method thereof

Abstract

The invention discloses a laser directional solidification preparation method for a superfine column crystal high-temperature alloy blade. The method specifically comprises the following steps that (1) a substrate is placed on a water-cooling copper plate, the <001> orientation of the substrate is made to be perpendicular to the water-cooling copper plate, the water-cooling copper plate is movably arranged in a water-cooling box, and the space below the water-cooling copper plate of the water-cooling box and the periphery of the water-cooling box are filled with cooling water; and (2) directional solidification deposition is conducted in a layer-by-layer scanning mode through laser to prepare a columnar crystal, in the scanning process, the scanning mode that in-layer lap joint is not conducted and inter-layer lap joint is conducted is adopted, and the water-cooling copper plate moves downwards along the inner wall of the water-cooling box after scanning of each layer is completed. According to the laser directional solidification preparation method, a stable ultrahigh directional temperature gradient can be maintained in a large range, and the overall orientation of the whole columnar crystal is kept.

Description

technical field [0001] The invention relates to the technical field of laser directional solidification, in particular to an ultrafine columnar superalloy blade and a preparation method thereof by laser directional solidification. Background technique [0002] The performance of engine blades is one of the important factors restricting the performance level of aeroengines, and it is usually required that the blades can work stably for a long time under high temperature and high pressure. However, the grain boundary perpendicular to the stress axis becomes the weak part of the ordinary cast superalloy, which leads to creep fracture of the superalloy at high temperature with a small amount of deformation. The directional crystallization vane eliminates the transverse grain boundaries that are sensitive to voids and cracks, and makes all grain boundaries parallel to the stress axis, thereby improving the performance of the alloy. [0003] Traditional casting directional solidi...

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Problems solved by technology

[0005] However, during the layer-by-layer deposition process of laser directional solidification, due to the influence of the surface tension of the molten pool liquid and the strong internal convection, the columnar crystals may deviate from the center position.

Although there have been many researches and achievements on the directional solidification of columnar crystals, no very effective solutions have been proposed for the above problems, which seriously affects the product performance of ultra-fine directional columnar crystals prepared by laser directional solidification, thus restricting the laser Application of Directional Solidification Technology in the Preparation of Ultrafine Columnar Superalloy Blades

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