Microscale and Ultrafast High Cycle Fatigue Testing of Ti Alloys

Proof of concept work on ultrasonic testing capable of fatigue testing at 20kHz with small-scale test pieces cut by focused ion beam (FIB) or laser micro-machining has been completed. FIB allows structures less than micron to a few microns to be cut allowing tests on single crystal, or bi-crystal test pieces. Laser micro-machining allows structures many tens to hundreds of microns to be cut so that tests pieces spanning tens or hundreds of grain diameters in cross section can be tested. Vibrating such structures at 20kHz allows fatigue testing in which 106 cycles is achieved in a little under a minute. This project will refine the sample geometries, testing procedures and supporting modelling capabilities. The method will be used to study how local microstructural neighbourhood in Ti alloys influences the location and number of cycles to high cycle fatigue crack initiation.

The project will feed into related activities in Oxford and other partner Universities collaborating in the EPSRC HexMat programme grant.

The research area aligns with Materials Engineering - Metals and Alloys and portfolio themes of both 'Engineering' and 'Manufacturing the Future' given the importance specific feature property measurement and optimisation is in these areas.