Ultrasonic Shot Peening (USP) on Ti-6Al-4V and Ti-6Al-2Sn-4Zr-6Mo Aero Engine Components

Author:  Stoll, Helm, Polanetzki, Wagner
Source:  Conf Proc 2011: ICSP-11 South Bend, IN USA (pgs. 371-376)
Doc ID:  2011062
Year of Publication:  2011
Abstract:  
Abstract Bladed disks (Blisks) have been developed and applied in the compressor sections of modern aero-engines to reduce the component weight and improve efficiency. Over time, the blisk design has been further optimized with respect to weight reduction resulting in thinner geometries in the web area of the disk. Consequently, precautions have to be taken into account to avoid stress induced distortion in thin walled areas during the peening process. MTU has therefore implemented ultrasonic shot peening as an alternative to the conventional shot peening process. For safety reasons detailed knowledge about the effect of this process on the properties of the blisk material, especially the fatigue behavior is a necessity. Most known is the conventional shot peening process, where the peening media is accelerated by pressurized air. A new method of this mechanical strengthening process is shot peening using bearing balls accelerated by an ultrasonic vibrating plate. The bearing balls are surrounded by a closed chamber that fits the geometry of the part to be peened. Only a very small amount of bearing ball peening media is needed. To understand the mechanics of this rarely researched process, extensive experiments were performed at MTU. The effect of Ultrasonic Shot Peening compared to conventional shot peening on the near surface area