Mechanical surface treatment technologies for improving HCF strength and surface roughness of blisk-rotors

Manufacturing of electron beam welded blade integrated disk (blisk) rotors requires the use of new mechanical surface treatment technologies. High durability and high efficiency of the blades are strict requirements for the component in general and have ideally to be increased by a mechanical surface treatment. Highly complex three dimensional shapes of the rotors blades and the need to treat the blades on the rotor due to post weld heat treatment are further challenges to solve. An increase of the technologies requirements is caused by limited clearance between adjacent blades and the lack space between the individual blisk stages. Conventional technologies reached their limits and have to be improved. This paper shows the capability of different mechanical surface treatments for treating blades on blisk-rotors. Compared to shot peening, surface roughness, residual stress depth distribution, and high cycle fatigue (HCF) are investigated on deep rolled and vibropeened specimen. Assets and drawbacks are shown and discussed as well.