Micro-cantilever testing of ⟨a⟩ prismatic slip in commercially pure Ti

Abstract

Four sizes (1, 2, 5 and 10 µm wide) of single-crystal α-Ti micro-cantilevers were manufactured from polycrystalline commercially pure Ti samples using a focussed ion beam. A nanoindenter was used to conduct micro-bending tests. The crystal orientation and alignment of the micro-cantilever beams were selected so as to activate only ⟨a⟩ slip on prism planes. A crystal plasticity finite element model was used to simulate the deflection behaviour of the cantilevers. The critical resolved shear stresses (CRSS) were determined via a reverse process of fitting the simulation results to the experimental load–displacement curves. The CRSS increased from 144 MPa for the 10 µm wide cantilevers to 566 MPa for the 1 µm wide cantilevers.

Keywords:

• micro-mechanics
• FIB
• nanoindentation
• CRSS
• titanium

Acknowledgements

The financial support from the Engineering and Physical Sciences Research Council (EPSRC Grant EP/E044778/1), Rolls-Royce plc and Timet is gratefully acknowledged. We would like to thank Prof. Fionn Dunne and his group (University of Oxford), and Prof. David Rugg (Rolls-Royce) for frequent insightful discussion and encouragement.