Equation of state remeasurements for aluminum and copper under low-impact loading

In this work, the Hugoniot equation of state for aluminum and copper under low-impact loading was measured by using the plane impact technique and laser Doppler velocimetry. The linear relationship between shock wave velocity and particle velocity was fitted by a least squares method, with D=5.28114+1.306(17)us for an Al pressure range from 2.5 to 13.9 GPa and D=3.9386+1.484(14)us for Cu at 5.7–47.5 GPa. The linear fitting correlation coefficient was greater than 0.99, which was better than the previous experimental data. The results demonstrate that the Doppler pin system has great advantages for measuring the Hugoniot EoS at low shock pressure compared with the electric pin technique The experimental data obtained in this work extend to a lower pressure range. This can provide more accurate Mie–Grüneisen EoS of Al and Cu under low shock pressure.