The influence of shock-loading path on the spallation response of Ta

18th APS-SCCM; 24th AIRAPT

Gray, G.T.^1 ; Bourne, N.K.^2 ; Livescu, V.^1 ; Trujillo, C.P.^1 ; MacDonald, S.^3 ; Withers, P.^3

Los Alamos National Laboratory, Los Alamos

NM

87545, United States^1

AWE Aldermaston, Reading, Berkshire

RG7 4PR, United Kingdom^2

University OfManchester, Sackville Street, Manchester

M60 1QD, United Kingdom^3

关键词: Complex Processes;    Damage evolution;    Dynamic damage;    Dynamic fracture behavior;    Electron back scatter diffraction;    Loading profiles;    Optical metallography;    Spall strength;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/500/11/112031/pdf
DOI  :  10.1088/1742-6596/500/11/112031

来源: IOP

【 摘 要 】

Spallation is well known to be a complex process strongly influenced by microstructure, loading path, and the loading profile yet often a singular spall strength is utilized in hydrocodes to quantify the dynamic fracture behavior of a material. In the current study, the influence of loading path on the spall strength and damage evolution in high-purity Ta is presented. Tantalum samples where shock loaded to three different peak shock stresses using both symmetric impact, and two different composite flyer plate configurations such that upon unloading the three samples displayed nearly identical pull-back signals as measured via rear-surface velocimetry. While the pull-back signals observed are similar in magnitude, the highest peak stressed sample resulted in complete spall scab separation while the two lower peak stresses resulted in incipient spall. The damage evolution in the soft recovered Ta samples was quantified using optical metallography, electron-back-scatter diffraction, and tomography. The effect of loading path on spallation and its ramifications for the stress and kinetic dependency of dynamic damage evolution is discussed.