Sound velocity measurement of LY12 Al alloy under tensile stress

Abstract
Experimentation for measuring sound velocity (C_k) under tension is described, and the determination of C_k is formulated in cases where spallation did and did not occur. Three experiments were conducted on LY12 Al alloy for measuring sound velocity under tension using a two-stage or single-stage gas gun. The sound velocities of LY12 Al alloy at different tensile stresses were extracted from the observed free-surface velocity traces. The extracted C_k data for LY12 Al alloy under tension is within the longitudinal (C_l) and bulk (C_b) sound velocity under ambient conditions, and is slightly deviated in value from the equivalent sound velocity C_e = 2C_lC_b/(C_l + C_b). The measured spall strength (σ_f) seems to slightly increase with increasing shock stress. The obtained results may provide insight into the spallation of metals and experimental data for numerical simulations of tension and spallation.