A kind of ultra-fine columnar superalloy blade and its laser directional solidification preparation method

Abstract

The invention discloses a preparation method for laser directional solidification of superfine columnar superalloy blades, which specifically includes the following steps: 1) placing a substrate on a water-cooled copper plate, and making the <001> orientation of the substrate perpendicular to the water-cooled copper plate, the water-cooled copper plate It is removably installed in a water-cooled box, and the space under the water-cooled copper plate of the water-cooled box and the outer periphery of the water-cooled box are filled with cooling water; 2) The columnar crystals are prepared by directional solidification and deposition by layer-by-layer scanning with a laser. During the scanning process, using A scanning mode in which layers are not overlapped but interlayers are overlapped, and the water-cooled copper plate moves down along the inner wall of the water-cooled box at the end of each layer of scanning. The laser directional solidification preparation method of the present invention can maintain a stable ultra-high directional temperature gradient in a wide range and maintain the overall orientation of the columnar crystals.

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...

AI Technical Summary

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

Images