| Fluoropolymer-matrix reactive materials as a type of reactive materials,chemical reactions and chemical energy release under shock load.Fluoropolymer-matrix reactive materials is used in the combat section,and it is necessary to ensure that the reactive materials is not subject to the damage of the damage,but also avoid the accident of the accident in the service transportation process,so it is important to study the mechanical properties of the reactive materials of fluorine.At present,the research on the formula of fluoropolymer-matrix reactive materials is concentrated in the preparation process and mechanical properties of the materials,and the research on the ignition mechanism is less,and these studies are based on the reactive materials of PTFE.In this paper,PTFE and THV reactive materials were prepared,and the mechanical properties and ignition characteristics were studied,and the application of fluorine polymer was provided for reference in the application of the warhead.The main contents are as follows:(1)The reactive materials was prepared by the process of cold pressure sintering process,and Al/W/PTFE(7.9/45.3/46.8),and the Ta/THV(57/43)and Hf/THV(62/38)were prepared by wet and mixed heat pressure process.The quasi-static compression experiment was carried out using the universal testing machine for four kinds of formula active materials.The results show that the surface of the PTFE reactive materials is compressed,and the surface appears to be a large number of cracks,and the cracks are extended to the surrounding,and if the compression can occur,it may be broken.When the THV reactive materials is compressed,there is no obvious crack in the surface,which is dented in the local area and shows the better compressibility energy.In stress-strain relation,the compression intensity of the reactive materials of PTFE is significantly higher than that of THV group reactive materials,Al/PTFE reactive materials,which are the highest compressive strength,72.5 MPa.The yield strength and elastic modulus of the material increase and the compression intensity decreases when the Al/PTFE reactive materials formula is added to the W powder,which may be related to the inclusion of the metal particle size.The yield strength of the reactive materials of Hf/THV is the maximum,and 30.17 MPa.The various compressibility indicators of the reactive materials of Ta/THV are lower than other formulative materials.(2)The dynamic compression experiments of four kinds of reactive materials under different strain rates were carried out.The results show that the dynamic compressive strength of the four formulations of reactive materials has the strain rate strengthen effect.PTFE-based reactive materials do not show obvious yield stage under different strain rate loading.With the increase of strain rate,THV-based reactive materials begin to show obvious yield stage,and strain softening occurs after reaching the ultimate strength.Based on Johnson-Cook fitting,the strength model parameters of four formulations of reactive materials were obtained.(3)Based on the Rankine-Hugoniot energy equation and the trinomial Grüneisen equation,the state equation of the dense material is derived.Based on the superposition principle of cold energy,Morse potential,mixture mixing theory and MC-Queen model,the equation of state of loose mixture material is obtained by using the isochoric line on the basis of the equation of state of dense state.The equation of state parameters of four kinds of fluoropolymer-matrix reactive materials are calculated.The results show that the sound velocity of PTFE-based reactive materials is significantly higher than that of THV-based reactive materials.The maximum sound velocity of Al/PTFE reactive materials is 2.805 km/s.After adding W,the sound velocity of the material decreases.The Grüneisen constant of Ta/THV reactive materials is 1.313,which may be due to the fact that the volume expansion coefficient of THV is larger than that of PTFE.(4)The impact reaction characteristics of fluoropolymer-matrix reactive materials were studied by dynamic impact experiments.It was found that the Al/PTFE reactive materials had the longest ignition delay time of 760μs and the highest fire light intensity.After adding W,the ignition delay time can be shortened,but the inertia of the material will be enhanced and the reaction intensity will be reduced.The ignition delay time of Hf/THV reactive materials is the shortest 300μs,the ignition duration is the longest 4455μs,and the fire light intensity is higher.Ta/THV reactive materials does not have ignition reaction.(5)Thermochemical reaction analysis was performed on fluoropolymer-matrix reactive materials.The results show that there is no obvious exothermic peak in the whole process of Al/PTFE reactive materials.After adding W to the Al/PTFE reactive materials,the reactive materialr reacts.This may be because the addition of W will catalyze the rupture of the metal oxide film,so that the internal reactive metal is dispersed and reacts with the small molecule of the fluoropolymer.For Hf/THV reactive materials,when the temperature reaches 515 °C,the oxide film of the metal hafnium loses its effect,and the exposed reactive metal reacts with the fluoropolymer molecules.(6)SHPB numerical simulation under different strain rates was carried out based on AUTODYN.The results show that for different formulations of reactive materials,the overall temperature rise is positively correlated with the strain rate during the dynamic impact process.The impact reaction mechanism of fluoropolymer-matrix reactive materials was analyzed,and the overall temperature rise of fluoropolymer-matrix reactive materials under reaction and unreaction conditions was calculated theoretically.The results of the overall temperature rise of the material obtained by numerical simulation are compared with the theoretical calculation,and the results are close.The analysis shows that in the whole impact process,the overall temperature rise of the reactive materials is also an important factor affecting the impact reaction. |
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