Orbital friction welding as an alternative process for blisk manufacturing

Linear friction welding (LFW) is used for the production of compressor blisks in modern turbine engines. Orbital friction welding (OFW) performs a circular motion in contrast to the linear motion applied during LFW. In order to display the influence of the different kinetics on the heat generation, both processes were compared using identical process parameters. The tests were performed on multi-orbital friction welding machine in the force-displacement mode. In a frequency range from 28 to 56 Hz the time necessary to achieve a displacement of 5 mm was measured for both processes. Using Ti-6Al-4V as the test material, it is shown that with similar welding parameters, shorter welding times are achieved with OFW. The reason for the faster heat generation is a continuous relative speed, higher contact pressure and a larger distance covered within one cycle of the process.