Melt-cast explosives are the most widely used energetic materials in military composite explosives,researchers have been unremittingly exploring high-energy and insensitive melt-cast explosives.In this work,a series o...Melt-cast explosives are the most widely used energetic materials in military composite explosives,researchers have been unremittingly exploring high-energy and insensitive melt-cast explosives.In this work,a series of dinitrophenyl-oxadiazole compounds were designed and prepared.These compounds have an ideal low melting point(80-97℃),good detonation performance(detonation velocity D=6455-6971 m/s,detonation pressure P=18-19 GPa)and extreme insensitive nature(impact sensitivity≥60 J,friction sensitivity>360 N).All these compounds were well characterized by nuclear magnetic resonance,fourier transform infrared spectroscopy,elemental analysis.Compounds 2,3 were unambiguously confirmed by X-ray single crystal diffraction analysis.As a result,their overall properties are superior to traditional melt-cast explosives trinitrotoluene(TNT)and dinitroanisole(DNAN)which may have excellent potential applications in insensitive melt-cast explosives.展开更多
A thermal fatigue behaviour of Co-based alloy coating obtained by laser surface meltcasting on the high temperature alloy GH33 was studied.The results show that after each time of thermal cycling,the final residual st...A thermal fatigue behaviour of Co-based alloy coating obtained by laser surface meltcasting on the high temperature alloy GH33 was studied.The results show that after each time of thermal cycling,the final residual stress was formed in the melt-casting layer which is attributed to the thermal stress and structural stress.Through the first 50 times of thermal cycling,the morphology of coating still inherits the laser casting one,but the dendrites get bigger;After the second 50 times of thermal cycling,corrosion pits emerge from coating,and mostly in the places where coating and substrate meet.The fatigue damage type of coating belongs to stress corrosion.展开更多
A melt-cast Duan-Zhang-Kim(DZK)mesoscopic reaction rate model is developed for the shock initiation of melt-cast explosives based on the pore collapse hot-spot ignition mechanism.A series of shock initiation experimen...A melt-cast Duan-Zhang-Kim(DZK)mesoscopic reaction rate model is developed for the shock initiation of melt-cast explosives based on the pore collapse hot-spot ignition mechanism.A series of shock initiation experiments was performed for the Comp B melt-cast explosive to estimate effects of the loading pressure and the particle size of granular explosive component,and the mesoscopic model is validated against the experimental data.Further numerical simulations indicate that the initial density and formula proportion greatly affect the hot-spot ignition of melt-cast explosives.展开更多
Searching for insensitive melt-castable energetic materials is still facing great challenges.In this work,we developed a promising strategy that is regulating the ratio of non-covalent interaction by fluorine atoms to...Searching for insensitive melt-castable energetic materials is still facing great challenges.In this work,we developed a promising strategy that is regulating the ratio of non-covalent interaction by fluorine atoms to regulate the melting point to develop new melt-castable energetic materials.Using this method,a highly sym-metric 1,2-difluoro-4,5-dinitrobenzene(DFDNB)was synthesized in one step and fully characterized.DFDNB has a desirable melting point(83.2℃),high decomposition temperature(>400℃),acceptable detonation properties(6786 m s^(-1),21.5 GPa)but superior safety performance(>40 J,>360 N),and excellent chemical compatibility with 1,3,5-trinitro-1,3,5-triazine(RDX)that make it a promising insensitive melt-castable energetic material.A detailed study based on crystal stacking,electrostatic potential,and intermolecular weak interactions in DFDNB and its isomers or analogs demonstrates that non-covalent interactions including the C-F…H,N-O…H hydrogen bonding,and C-F…O halogen-like bonding play an important role in regulating the melting point.展开更多
基金the projects of NSFC(Grant No.22175025)for their generous financial support。
文摘Melt-cast explosives are the most widely used energetic materials in military composite explosives,researchers have been unremittingly exploring high-energy and insensitive melt-cast explosives.In this work,a series of dinitrophenyl-oxadiazole compounds were designed and prepared.These compounds have an ideal low melting point(80-97℃),good detonation performance(detonation velocity D=6455-6971 m/s,detonation pressure P=18-19 GPa)and extreme insensitive nature(impact sensitivity≥60 J,friction sensitivity>360 N).All these compounds were well characterized by nuclear magnetic resonance,fourier transform infrared spectroscopy,elemental analysis.Compounds 2,3 were unambiguously confirmed by X-ray single crystal diffraction analysis.As a result,their overall properties are superior to traditional melt-cast explosives trinitrotoluene(TNT)and dinitroanisole(DNAN)which may have excellent potential applications in insensitive melt-cast explosives.
基金Project Sponsored by Committee on Science and Technology of Guizhou Province(943068)
文摘A thermal fatigue behaviour of Co-based alloy coating obtained by laser surface meltcasting on the high temperature alloy GH33 was studied.The results show that after each time of thermal cycling,the final residual stress was formed in the melt-casting layer which is attributed to the thermal stress and structural stress.Through the first 50 times of thermal cycling,the morphology of coating still inherits the laser casting one,but the dendrites get bigger;After the second 50 times of thermal cycling,corrosion pits emerge from coating,and mostly in the places where coating and substrate meet.The fatigue damage type of coating belongs to stress corrosion.
基金the National Natural Science Foundation of China(Grant No.11772056)the NSAF Joint Fund(Grants No.U1630113)and the Innovative Group of Material and Structure Impact Dynamics(Grant No.11521062)。
文摘A melt-cast Duan-Zhang-Kim(DZK)mesoscopic reaction rate model is developed for the shock initiation of melt-cast explosives based on the pore collapse hot-spot ignition mechanism.A series of shock initiation experiments was performed for the Comp B melt-cast explosive to estimate effects of the loading pressure and the particle size of granular explosive component,and the mesoscopic model is validated against the experimental data.Further numerical simulations indicate that the initial density and formula proportion greatly affect the hot-spot ignition of melt-cast explosives.
基金supported by the National Natural Science Foundation of China(No.22105023).
文摘Searching for insensitive melt-castable energetic materials is still facing great challenges.In this work,we developed a promising strategy that is regulating the ratio of non-covalent interaction by fluorine atoms to regulate the melting point to develop new melt-castable energetic materials.Using this method,a highly sym-metric 1,2-difluoro-4,5-dinitrobenzene(DFDNB)was synthesized in one step and fully characterized.DFDNB has a desirable melting point(83.2℃),high decomposition temperature(>400℃),acceptable detonation properties(6786 m s^(-1),21.5 GPa)but superior safety performance(>40 J,>360 N),and excellent chemical compatibility with 1,3,5-trinitro-1,3,5-triazine(RDX)that make it a promising insensitive melt-castable energetic material.A detailed study based on crystal stacking,electrostatic potential,and intermolecular weak interactions in DFDNB and its isomers or analogs demonstrates that non-covalent interactions including the C-F…H,N-O…H hydrogen bonding,and C-F…O halogen-like bonding play an important role in regulating the melting point.
