Magnetically Driven Isentropic Compression of 45 Steel

The technique of magnetically driven isentropic compression has many advantages over previous experimental techniques of quasi-isentropic compression, such as the smoothly increasing pressure loading to a high magnitude without any initial shocks, the ability to investigate several samples under identical loading conditions in one shot, high benefit-cost ratio, etc.The main parameters of CQ-1.5 rebuilt by Institute of Fluid Physics, CAEP, are detailed.This apparatus aims at isentropic compression and driving high-speed flyers, its designed maximum pressure is 50 GPa.The samples of 45 steel are isentropically compressed by CQ-1.5 to a pressure as high as 47.5 GPa without any appearance of shock, a Doppler pins system (DPS) is used to record the velocity history of flyers.We use a backward integration method to treat the experimental data, and obtain thep-V relation of 45 steel under quasi-isentropic compression.We also ascertain the parameters of 3 forms of isentropic equation of 45 steel.The maximum isentropic pressure in this work is 47.5 GPa.