Neutron Radiography Detection of Residual Core in Turbine Blades

Hollow turbine blade is one of the most important hot end components of aero-engine. The residual core produced in the blade manufacturing process will seriously affect the cooling effect, which will lead to blade overheating and premature failure, causing fatal damage to the engine. The common non-destructive testing methods cannot detect the residual core in hollow blades effectively because the detectable area cannot cover the whole blade or the detection sensitivity is insufficient. The principle of neutron radiography is similar to that of X-ray radiography, but the attenuation characteristics are quite different, which makes it possible to detect the residual cores. Neutron radiography has been used to detect the residual core in turbine blades since 1970s abroad and related company standards have been established. The research work in China is less than 10 years, although experimental application has been carried out on some blades, the problems of lack of inspection standards and neutron source resources need to be solved.