Technological Aspects of Intense Pulsed Electron Beam Application for Properties Improvement and Repair of Gas Turbine Engine Blades from Titanium Alloys

摘要

The present paper reviews the results achieved by the application of intense pulsed electron beams (IPEB) for surface processing of titanium alloy compressor blades of aircraft engines. The irradiation of these components was carried out in the GESA-1 accelerator under the following conditions: electron energy -E=115-120 keV; pulse duration - τ=20-40 μs; energy density in a pulse - w from w=16 J/cm~2 to w=50 J/cm~2 and number of pulses - n from n=1 to n=10. The results of the investigations of the irradiated blades obtained using EAS, X-ray analysis, SEM and TEM methods were discussed. It is shown that IPEB treatment with lower values of energy density (w=18-20 J/cm~2) induces rapid melting, ablation and solidification which leads to the formation of non-equilibrium microstructures. This kind of irradiation (w= 18-20 J/cm~2) leads to surface smoothing and rapid solidification of the material in the surface layer with a thickness around 2-5 μm. As a result, surface roughness of the blades can be decreased from R_a=0.15-0.25 μm up to R_a=0.08-0.12 μm. Operating at low energy densities the most important operating characteristics of compressor blades were improved significantly by irradiation with IPEB. At high values of the energy density (w=25-50 J/cm~2) intense ablation takes place during a pulse. This operating regimes of irradiation can be used for repair of compressor blades with resistant coatings.