Investigation of anomalous compressibility of docosane and cerium under shock-wave action

The behavior of docosane (C22H46) and cerium (Ce) under shock-wave action has been investigated. It was shown that the solid docosane demonstrate elastic-plastic properties and has abnormal compressibility at pressures below 100 MPa. It was found that the strength of docosane remains practically constant and equals to about 24 MPa when passing through the melting point. We determined the shear stress and evolution of compression wave in the area of cerium anomalous compressibility. The value of longitudinal stress at which the γ-α phase transition occurs is also determined. It is shown that the phase transition pressure, under dynamic and static compression coincides and is equal to 0.8 GPa. The spall strength of cerium rises from 0.3 to 0.7 GPa when strain rate increase from 2.1 x 104 to 1.02 x 106 s-1.