| The preparation of MESMs specimens of a certain strength is the main means to ensure that the fragment has a certain penetration power and improve the target damage effect. Combining traditional powder metallurgy method, the main method of MESMs molding is molding method, the resulting mixture is mostly porous state. Based on the predecessors’ research on equation of state (EOS) for porous materials. A new equation of state is developed for porous materials in which the contribution of electrons is considered explicitly under the condition of different porosity. In this paper, what we have studied has certain guidance and reference value for the study of application of porous materials and the study of the multifunctional energetic structural materials (MESMs) under condition of high-temperature, high-pressure and ultrahigh pressure, ultra temperature. The main contents and conclusions are as follows:(1) The theoretical research methods for the equation of state for porous materials are introducedWu-Jing and Viljoen method for porous materials were introduced. Wu and Jing derived EOS from thermodynamic considerations along isobaric path with assumption that specific heat at constant pressure remains same, which is based on Mie-Gruneisen EOS. Viljoen modified the Wu-Jing method without considering parameter Y, HEL and ks. We pointed out the problem in both Wu-Jing and Viljoen method:the contribution of electrons was ignored.(2) The influence of electronic thermal motion on developing equation of state is studied. We also optimized the equation of state for porous materialsAccording to the different crystal types, the thermal behavior of electrons in metal crystals and ionic crystals were studied. The population in the system, internal energy, pressure and other parameters were described, and the electronic heat capacity, specific heat, coefficient of Gruneisen were derived. Problems such as the selection of parameter values in practical applications were analyzed.After taking the influence of electronic thermal motion into consideration, the EOS for dense materials and porous materials was linked along isobaric path. Based on this, A new EOS was developed, in which we use an important parameter R to describe the influence of electronic thermal motion in EOS.(3) The application of the equation of state for porous materials studied in this paper is studied.Ther calculating and fitting work for the EOS model is done on both the single-component porous materials such as copper, aluminum, iron, the multi-component mixtures such as W/Cu and MESMs such as Al/Ni. We optimized the Up-Us relationship which was also used to describe the equation of state traditionally. Comparisons between calculated and predicted results and the experimental data were made, which has proved the necessity of taking the influence of electronic thermal motion into consideration. Also the effectiveness and universality of the EOS developed in this paper was proved. |
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