New progress in research on neutron photodestructive testing of engine blades

[ China Instrument Network Instrument Development ] Recently, the research team of Nuclear Energy Safety Institute based on the strong current neutron source scientific device HINEG, and Harbin Institute of Technology jointly carried out a model of aeronautical engine turbine blade residual core neutron photography experimental research, successfully detected The micro-residue core inside the blade provides an important support for the manufacturing inspection process of aero-engine turbine blades.

Neutron photography is a method of detecting an object that needs to be inspected by a uniform collimated neutron beam with a small divergence angle. Since the neutron has no charge, when it penetrates the object, it does not have an electron coulomb force with the extranuclear electrons of the atom, so that it can easily pass through the electron layer and directly hit the nucleus to generate a nuclear reaction such as absorption reaction and fission. Reaction or scattering reaction, and the like. If an image detector is used for recording and display imaging, a comprehensive information image representing the changes in nuclide, density and thickness inside the object can be obtained, and a neutron photographic perspective image can be obtained.

As an important component of non-destructive testing technology, neutron photography has good complementarity with X-ray photography. X-ray technology cannot reflect the characteristics of the nucleus of material materials. Neutron photographic technology has inherent advantages in material identification. For example, neutron photography can see the location and shape of lightweight materials in a combination of lightweight materials and heavy materials. There are a wide range of needs and applications in the fields of aerospace, defense and military, and homeland security.

Turbine blades are the key components of aero-engine thrust generation. The residual ceramic core during blade investment casting will reduce its cooling performance and even block the cooling passages, causing the blades to overheat and damage, thus seriously affecting engine safety. Therefore, the detection of the residual core inside the engine blade is extremely important.

The HINEG neutron source is 6.4×1012 n/s, which is highly sensitive and fast thermal neutron photodetection after slow collimation. In this experiment, the HINEG thermal neutron camera terminal was used to clearly detect the residual core with the internal mass of the blade in the order of mg, which showed the excellent neutron photographic resolution characteristics of HINEG. The experimental results provided the manufacturing process for the turbine blade of this model. Important data reference.

At present, the Nuclear Energy Safety Institute has built a thermal neutron and fast neutron camera terminal based on the strong neutron source neutron source scientific device HINEG. It has successfully carried out a series of neutron photography experiments and is currently developing mobile neutron camera systems. To meet different types of on-site inspection needs.

(Source: Baidu Encyclopedia, Hefei Institute of Materials, Chinese Academy of Sciences, Institute of High Energy Physics, Chinese Academy of Sciences)