X-ray microtomography study of the spallation response in Ta-W

18th APS-SCCM; 24th AIRAPT

McDonald, S.A.^1 ; Cotton, M.^2 ; Millett, J.C.F.^2 ; Bourne, N.K.^2 ; Withers, P.J.^1

Manchester X-ray Imaging Facility, School of Materials, University of Manchester, Manchester

M13 9PL, United Kingdom^1

AWE, Aldermaston, Reading

RG7 4PR, United Kingdom^2

关键词: Damage evolution;    Dynamic tensile;    Physical damages;    Pulse durations;    Spall strength;    Three dimensions;    Void coalescence;    X ray microtomography;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/500/11/112045/pdf
DOI  :  10.1088/1742-6596/500/11/112045

来源: IOP

【 摘 要 】

Measurement of the damage field resulting from spallation due to shock induced loading is an important aspect of understanding the mechanisms controlling the dynamic tensile failure process. Furthermore, the ability to observe in three-dimensions, and in a non-invasive manner, the physical damage present in a spalled sample post-impact can provide important data for predictive damage models. In the current study, the influence of peak shock stress and pulse duration on the spallation damage response in the tantalum alloy Ta-2.5% W is presented. Rear surface velocimetry (HetV) measurements from plate impact experiments have been combined with 3-D characterisation and quantification of the resulting damage evolution in the recovered targets using X-ray microtomography. Small differences in spall strength are observed - an increase in the pulse duration results in a decrease in spall strength, while spall strength increases with increase in peak shock stress. The level of damaged induced (void coalescence) is more significant for an increase in pulse duration, with a local damage volume fraction double that of the case for an increase in peak shock stress.