Abstract
In the preceeding study on the effect of hydrostatic pressure on the flow stress of polycrystalline cadmium, it was indicated that the rate of increase of the flow stress Δσ/σ due to 600MPa was larger than that of the shear modulus ΔG/G due to the same pressure. In the present study, tensile tests were made under hydrostatic pressures of 10 and 600MPa on cadmium single crystals of four different orientations.
The results obtained are summarized as follows.
(1) The yield stress for the slip in the basal plane increased by 6.9% at 600MPa and this amount of the rate of increase was in good agreement with ΔG/G of 7.0% on the basal plane. The value of Δσ/σ for the basal slip increased monotonically with an increase of strain.
(2) A non-basal slip system operative in cadmium crystals was {1122} ‹1123›. The vaule of Δσ/σ for this slip was 16 to 18% and it was considerably larger than ΔG/G of 4.9% on the {1122} plane. Further, a decrease in the strain hardening rate due to high pressure occured in the high strain range near to the maximum load point.
(3) In the extention along ‹0110› and ‹1120›, Δσ/σ for the deformation twinning was smaller than those for the basal and the {1122} ‹1123› slip. Especially in the ‹0110› crystals the flow stress σ and Δσ/σ for the slip within the twin block were well consistent with those for the {1122} ‹1123› slip.
