Influence of microstructure on the dynamic high-temperature elastic moduli of aluminum

The dynamic elevated temperature elastic properties of single-crystal and polycrystalline aluminum have been studied by employing a laser pulse technique to produce propagating stress pulses in slender rods. The behavior at temperatures between 25 and 500°C of monocrystals and slender polycrystalline specimens having a cold work texture is described. Experimental results are presented for the polycrystals as a function of thermomechanical history and compared to the results for single crystals of known orientation. The results are evaluated in terms of dislocation dynamics and anisotropy of the lattice in single crystals and polycrystals. Results show that the longitudinal wave velocity increases with the annealing of dislocations and then decreases with the disappearance of texture in polycrystals.