J. Cirne, R. Dormeval, et al.
J. Phys. IV France 134 (2006) 851-856
The effect of aspect ratio on the compressive high rate deformation of three metallic alloysS.M. Walley1, D.D. Radford2, 0 and D.J. Chapman1
1 PCS Group, Cavendish Laboratory, University of Cambridge CB3 0HE, UK
2 Cambridge University Engineering Department, Trumpington Street, Cambridge CB2 1PZ, UK
Published online: 26 July 2006
Metallic cylinders of rolled homogeneous armour (RHA) steel, Ti6Al4V, and FNC tungsten alloy of four different length l to diameter d ratios (dimensions in mm): 8/4, 4/8, 10/8, 8/10) were deformed at high rates of deformation using a direct impact Hopkinson pressure bar. Highspeed photographic sequences of the deformation were taken using a Hadland Imacon 790 imageconverter camera working at either 1 or 2 x 104 frames/s. It was found that titanium alloy cylinders of all four aspect ratios shear-banded and fractured, but that cylinders made from RHA steel and FNC tungsten behaved in a ductile manner when l/d < 1 but in a brittle manner when l/d > 1. We conclude that adiabatic shear banding is not just an inherent material property but that in some materials size effects/geometry can trigger this phenomenon.
© EDP Sciences 2006