Influence of Shot-Peening on fatigue behavior Orbital Friction Welded Titanium Joints

Author:  U. Raab C. Becker, L. Wagner
Source:  Conf Proc 2014: ICSP-12 Goslar, Germany (pgs.168-172)
Doc ID:  2014070
Year of Publication:  2014
Abstract:  
The usage of friction welded blisks in turbine engine compressors comprises an increase of effectiveness of the compressor and weight savings due to the omission of the disk blade attachment. The combination of the Ti-6Al-4V modifications mill annealed as the blade material and bi-modal as the disc material demonstrates a concept for a multi-material high pressure compressor blisk with operating temperatures up to 350°C. Linear friction welding (LFW) is the state of the art welding process for the production of joined titanium blisks. Orbital friction welding (OFW) represents an alternative process where the discontinuous linear motion of the LFW is replaced by a continuous circular motion, to achieve an improved heat generation. Bending fatigue tests were performed in the as-welded and stress relieved condition to demonstrate the effect of residual stresses developed during orbital friction welding on the fatigue performance of the welds. Additionally, shot peening was performed on the heat treated welds to further improve the fatigue performance.