Shot Peening Method for Aerofoil Treatment of Blisk Assemblies

Advanced compressor designs today often include blade integrated disc (blisk) rotors, with high demands on aerodynamic performance, resistance againsthigh load levels and foreign object damage (FOD).To increasethe highcycle fatigue (HCF) strength, compressive residual stresses are introduced into the surface and subsurface layer of aerofoil, fillet (transient area between aerofoil and disk) and annulus (intermediate area between aerofoils). For generatingcompressive residual stresses several different industrial production processes are used, beside ultrasonic shot peening, laser shock peening, deep rolling and shot peening wet and dry with glass or ceramic media is shot peening with steel media the mostly used technology. However, depending on the size of the componentaccessibility for tools might be limited and the set-up of economical production techniques challenging for blisk shot peening.This paper gives an introduction into blisk shot peening, a sophisticated mechanical surface technology for treating aerofoil surfaces of blisk rotors using special designed calliper nozzles assolution for introducing uniform residual compressive stress states, as well as consistentshot peening coverage levels.