Shock deformation of polycrystalline aluminium

Defect Generation in Shock-Wave Deformation

“…The experimental investigations conducted to date (39)(40)(41)(42)(43)(44)(45)(46) are unanimous in indicating that shock loading produces a high density of point defects. The dynamic strain induced by shock loading is usually represented by…”

Response of shock wave deformation in AA5086 aluminum alloy

“…The dislocation substructure observed in the deformed sample (P ¼3.5 MPa) was similar to that observed by Rose and Berger [10]. A series of low magnification bright-field TEM micrographs were taken from the same area in the matrix (a triple junction) at different specimen tilt conditions to qualitatively construe the dislocation density (Fig.…”

“…On the contrary Higgins [8] and Trueb [9] reported no such changes in texture of copper and nickel. Rose and Berger [10] were the first to report micro-structural changes after shock wave loading. Dhere et al [11] observed texture changes in commercially pure aluminum and compared the changes in texture and sub-structural evolution between conventional cross-rolling and shock wave deformation.…”

Dynamic fracture by spallation in metals

“…For example, point defect and dislocation densities are increased more by shock loading than by static deformation [7], [8]. The effects of initial microstructure described earlier will be manifested in the same way if the defects are introduced in the loading cycle prior to fracture.…”

“…Perhaps the most fundamental of these is the work of Born and Furth [ 13], who calculated the extension at which a face-centered-cubic array of points bound together by Leonard-Jones forces becomes unstable toward further deformation. Discussion of their methods is given by Norton, et al [1][2][3][4][5][6][7][8][9][10][11][12][13][14] and by Kelly [15]. The conclusion is that the critical fracture stress is approximately ten percent of Young's modulus.…”