Application of high accuracy pulsed electron beams for modifying gas turbine engines blades airfoil in its manufacture and repair.

This work refers to nano technologies class, because the process proceeds on the molecular level and the total thickness of formed surface layers does not exceed  6 - 10 μm, and it is of no analogous in the aero engine branch of industry.
During several years investigations in this field being carried out jointly with the Moscow Aviation College (MAI) on compressor and turbine blades of serious produced engines using the GEZA accelerator designed by the Efremov Research Institute NIIEFA (
НИИЭФА) in Saint- Petersburg has shown large positive effect that was proved by endurance tests of the technological engine. They have confirmed blade material endurance limit increase by 10÷40%, erosion resistance - 2 times, heat resistance -  more than 3 timesраза, hot salt corrosion - more than 3 times, i.e. significant increase of component material performance;

Foto 1. External view of the GEZA-2 accelerator in NIIEFA Institute.

Special interest presents the results of fatigue tests from which it follows that the formed coating prevents coming out to the surface fatigue cracks originated in the under surface layer.
Observed improvement of mechanical properties permits to increase reliability, and in combination with other works permits to increase the produced engines life. In August, 2011 our enterprise put into experimental operation the unique electron beam installation «GEZA-MMP» to treat with high accuracy pulsed electron beams (
СИЭП) airfoil surfaces of compressor and turbine blades in order to increase its life at the expense of improvement of the above mentioned parameters of the material surface layer. This installation was manufactured  by the Efremov Research Institute NIIEFA (НИИЭФА) in Saint- Petersburg according to the Technical assignment developed by Chernyshev MME specialists (A.G. Paikin, A.F. Lvov, A.D. Teriaev),  jointly  with MAI (chair 205, Prof. V. A. Shulov). 

Photo 2. General view of the GEZA-MMP installation at the Chernyshev MME

Treatment is carried out in the vacuum chamber where the planetary mechanism is located being a magazine for 40 parts and providing sequence feed of them into the treating zone (electron beam) and rotation around its axis. The whole process excluding loading and unloading the parts is automatic. Total cycle time of treatment of 1 engine set of components (2 loads) is approximately 8 hours. The vacuum chamber where blades are treating is shown on Photo 3.

Photo 3. Vacuum chamber of the GEZA-MMP installation

Observed improvement of mechanical properties permits to increase reliability, and in combination with other works permits to increase the life of the manufactured products.  The external appearance of overhauled engine turbine blades being treated on the GEZA-MMP installation is shown on Photo 4.

Photo 4. Blades repaired on the GEZA-MMP installation

As far as we can judge by materials published in our country and abroad and materials of  conferences this installation as well as the developed technological process until today are unique and being of no analogues in the domestic engine building industry and also abroad.
The CIAM work is recognized as one of the most important and by all means it will be further developed and will find practical application in the most part of the aero engine manufacturing enterprises.

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