| Explosive network was an important initiation control components in directional warhead and shaped-charge warhead.Explosive network charging requires not only small critical size,but also high charging precision and simple process,the existing explosive network charging cannot fully meet the charging requirements in terms of complex structure,molding efficiency,and quality uniformity.In this paper,based on the direct ink writing of energetic materials,the UV curing system is introduced into the energetic ink,two kinds of dual curing energetic ink systems are designed,and the groove of explosive network is charged by the micro-pen direct writing technology.The specific contents are as follows:In the first place,the formula of energetic ink was selected and optimized from the main explosive and binder system.CL-20 was selected as the main explosive,hydroxyl-terminated polybutadiene(HTPB)and 3,3-diazomethyl oxy-butyl-tetrahydrofuran copolymer(PBT)were selected as the thermal curing binder respectively,toluene-2,4-diisocyanate as the curing agent(TDI),and triphenyl bismuth(TPB)as the curing catalyst,the formula of the UV curing binder system was obtained as follows:organic fluorine acrylic ester(47.5 wt%),1,6-Hexanediol diacrylate(47.5 wt%)and TPO(5 wt%).Secondly,the formula and direct writing process of HTPB-based dual curing energetic ink were studied.The R value was determined to be 1.2,the optimal ratio of dual curing binder system was 2:1,the content of explosive was determined to be 83 wt%by rheological properties test.HTPB-based dual curing energetic ink micro-pen direct writing process was determined by studying the influence of the parameters on the molding effect,and HTPB-based thermal curing energetic ink was compared.Shore D digital hardness tester,Scanning electron microscope(SEM)and X-ray diffractometer(XRD)were employed to characterize the curing efficiency and quality,the microstructure and crystal form of the samples.And the thermal decomposition property,mechanical sensitivity and detonation performance of the sample were measured.The results showed that HTPB-based dual curing energetic ink had faster rate and better quality of curing compared with HTPB-based thermal curing energetic ink,and the surface of the sample was smooth,the internal explosive particles were evenly dispersed,the crystal form was still?type.The activation energy of the sample was significantly improved,the mechanical sensitivity of the sample was reduced.The detonation critical thickness of the sample in the groove with charge width of 1 mm was 1.011 mm.When the density was 1.51g·cm-3,the detonation velocity was 6168 m·s-1.Then,the formula and direct writing process of PBT-based dual curing energetic ink were studied.The R value was determined to be 1.1,the ratio of dual curing binder system was 2:1,the content of explosive was determined to be 82 wt%.PBT-based dual curing energetic ink micro-pen direct writing process was optimized,and PBT-based thermal curing energetic ink was compared.Shore D digital hardness tester,SEM and XRD were applied to characterize the curing efficiency and quality,the microstructure and crystal form of the samples.The thermal decomposition property,mechanical sensitivity and detonation ability of the sample were tested.The results showed that PBT-based dual curing system had better effect of curing compared with PBT-based thermal curing energetic ink,and the surface of the sample was smooth,the sample was had no obvious pores,the crystal form was still?type.The activation energy of the sample was slightly decreased,the special height H50 was increased by 20 cm,and the friction sensitivity was decreased from 100%to 96%.The detonation critical thickness of the sample was 0.387 mm.When the density was 1.46 g·cm-3,the detonation velocity was 6442 m·s-1.The sample could successfully detonate in the charge groove with 90°corner,and realize stable detonation in the groove of“one in and four out”explosive network. |
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