It is intended in the present paper, as one of the series of study on the influence of hydrostatic pressure on the mechanical behavior of polycrystalline metals, to investigate the influence of hydrostatic pressure soaking on the structural change of deformed metals, using the Laue method of X-ray back reflection. From the present study it had been elucidated that the use of the Laue method of X-ray back reflection had proved fruitful experiment, though it is misorientation, for the study on the influence of the hydrostatic pressure on plastic deformation of metals, showing not only the density in edge and screw dislocation but also the vacancy and presence of interstitial atoms in the deformed metals. From the present analytical and experimental studies on pressure soaking of 2000kg/cm2 for coarse-grained sheet specimen of aluminum pulled at atmospheric pressure, the following conclusions have been made:
(1) As the result of measurement of dislocation density, no change in dislocation density which is represented by torsion tensor has been observed immediately after the pressure soaking.
(2) The density of imperfection which is represented in Riemann-Christoffel curvature tensor has remarkably changed immediately after the pressure soaking. It is considered therefore that the arrangement of dislocation and the density of vacancy are influenced by subjection of hydrostatic pressure to the sheet of polycrystalline metals.
(3) The structural recovery which has been examined by the decrease in both density of dislocation and imperfection is observable in the elapse of 24 hours after the pressure soaking.