Preliminary Investigation On Phase Transition Of Zirconium Under Magnetically Driven Quasi-isentropic Compression And Electromagnetic Expansion Ring Simulation

Phase transition is one of the important fields of the Kinetics of Materials Research. mature experimental methods are static high-pressure compression and shock compression. respectively, approximate the corresponding isotherms and adiabat. Thermodynamic theory shows that the isentropic line between isotherms and adiabat, quasi-isentropic compression phase transition contacts the two research methods, and has important scientific significance. Zirconium metal will have α-ω phase transition at a lower pressure, the α-ωphase transition pressures reported are much different (two to ten GPa). and concentrated in the shock loading, only the U.S. Los Alamos National Laboratory reported the quasi-isentropic compression phasedata, this work is still blank in country, so work in this area has a high scientific value. The main objective of this work is to investigate the phase transition of the pure Zr combing experiments with numerical simulation.The experimental device driven by the magnetic and electric gun metal zirconium quasi-isentropic compression phase transition experiments and the shock compression phase transition experiments, measured under different load pressure waveform zirconium interface, free surface particle velocity profile, profile contains a phase transition quasi-isentropic compression phase transition pressure, phase transition relaxation time, the old and the new phase of the physical characteristics and other useful information. The results show that the phase transition pressure was significantly increased compared with the shock compression phase transition, zirconium quasi-isentropic compression, with the available experimental results and theoretical analysis; the same peak in the load pressure, CQ-1.5and CQ-4phase transition pressure is basically the same; load pressure rise time is longer, thicker samples, the phase transition corresponds to the speed of time "platform" wide. In addition, the use of LS-DYNA software with electromagnetic modules to the load area of the magnetic drive experimental setup geometry optimization, the optimal model, phase transition experiments the specific requirements of the experimental setup at this stage operating performance for this article, proposed reinforcement configuration, and applied to the experiment; analysis of some factors in the experiment.In addition, the use of LS-DYNA software to simulate the loading process of electromagnetic expansion loop (calculated results and experimental results are in good agreement), analysis of several key factors that need attention in the electromagnetic expansion loop experimental design. The simulation found that: wound solenoid connection with a gap circle method is superior to uniform transition spiral coil; solenoid gap should decrease with the increase of the diameter of the coil; under the premise to ensure that insulation should minimize the spiral coil wire spacing, spiral coil and the specimen ring gap; analysis of the expansion caused by the spiral coil gap at the slash connection ring axial displacement and axial stress distribution; first proposed a double helical coil model can significantly reduce the axial displacement and axial stress.