Low cycle fatigue performance of SLM Ti-6Al-4V aero-engine bracket at 200°C: An experimental study

In this work, the Low Cycle Fatigue (LCF) performance of a weight optimized SLM Ti-6Al-4V bracket in a ‘struts & connectors’ shape has been investigated through the displacement controlled LCF testing at 200°C. The bracket was designed to operate under Thermo-mechanical loading, i.e. an elevated temperature environment under mechanical loading, during engine normal operation. The bracket was demonstrated to have met the LCF target cycles for the defined displacement loading, which simulated the maximum possible loading under aero-engine flight operations. Subsequently the same bracket was also subjected to a higher level of cyclic displacement loading to allow the bracket to experience some level of plastic strains in the structure, to assess the LCF performance of the bracket under the one-off extreme event such as a Fan Blade Off event. The successful outcome of the elevated temperature LCF testing of the bracket is a significant forward step towards adopting SLM technology for safety critical load bearing applications.