Nghiên cứu chế tạo thuốc nổ nhiệt áp dùng cho đạn ĐNA 7v tt tiếng anh

1 MINISTRY OF EDUCATION AND TRAINING MINISTRY OF NATIONAL DEFENCE ACADEMY OF MILITARY SCIENCE AND TECHNOLOGY TRAN QUANG PHAT STUDY ON PRODUCTION OF THERMOBARIC EXPLOSIVE USED FOR DNA-7V WARHEAD Specialization: Chemical engineering Code: 952 03 01 SUMMARY OF DOCTORAL THESIS Hanoi - 2020 This thesis has been completed at: Academy of Military Science and Technology, Ministry of Defence Scientific supervisors: Assoc Prof Dr Ngo Van Giao Assoc Prof Dr Ninh Duc Ha Reviewer 1: Prof Dr Thai Hoang Vietnam Academy of Science and Technology Reviewer 2: Assoc Prof Dr Vu Minh Thanh Academy of Military Science and Technology Reviewer 3: Dr Nguyen Duc Long Institute of Propellant and Explosive The thesis was defended in front of the Doctoral Evaluating Council at Academy level held at Academy of Military Science and Technology at 8:30 AM, date … month … , 2020 Công nghiệp Việt Nam The thesis is able to be found at: - The Library of Academy of Military Science and Technology; - Vietnam National Library INTRODUCTION The ugency of the thesis topic Thermobaric weapon is a kind of advance, model weapon which is based on thermobaric explosive (TBE) This weapon has been developed in a number of well-defence countries had and is novel milestone of military technology in the late of 20 century This weapon is particularly effective in enclosed spaces such tunnels, buildings anf field fortifications Army of some countries are equiped with thermobaric weapons as RPO-A, RPO-M, TBG-7V, TBG-29V (Russian); GTB-7G (Bungaria); BLU-118/B (USA); AGM-114N Hellfire (UK) Finding advantaged features of this weapon, our army imported a batch of TBG-7V and has just started to study them for purpose of manufacturing this weapon by ourselves In the novel mission, the work of research on TBE plays vital role Content of the thesis is new completed studies in Vietnam and meets the need of the ugency reality Therefore, the thesis determine that TBE is main object The aims - Study on selecting of measurement method for power of TBE and effects to power - Study on selecting of suitable component and establishment of technical steps for manufacturing TBE and casting TBE into DNA-7V warhead - Determination of a number of energy and technical features of TBE The ranges Component, technology of TBE; measurement of parameters of air shock wave front - maximum overpressure (Δpmax) and positive impulse (Itc), heat and temperature of explosion, dimensions of fireball The research method The thesis uses the following technology: Preparing TBE casting sample; VST; DSC; SEM; EDX; EDX-Mapping; evaluation of physicalmechanical, energy, power features; and testing DNA-7V warhead The scientific and practical meaning The thesis produces TBE successfully and establishment of measurement method of power and technical features of TBE that are suitable with domestic condition The layout The thesis contains 126 pages and is constructed as following: Overview pages; chapter - Introduction, 35 pages; chapter - Experiments, 15 pages; chapter - Results and Dicussion, 60 pages; Conclusion pages; List of published scientific reports, page and 88 references Chapter INTRODUCTION Overview about TBE, TBE device, explosive mechanic of TBE, components of TBE and component of TBE for DNA-7V warhead Making power of explosives more clearly, air shock wave, explosive region Foreign research on TBE and power of TBE The issues need to be studied, solved in the thesis Chapter OBJECTS AND RESEARCH METHOD 2.1 The objects Main object are TBE which are done by the thesis and by Russian Relating objects as materials, equipments, technical process, testing methods 2.2 Chemicals and equipments 2.1.1 Chemicals RDX explosive, grade 1; Al powder,  99,7% pure, particle size: ≤ m; ≤ 45 m; ≤ 75 m; AP,  99,5% pure, particle size: 105÷154 m, 180÷280 m; 280÷450 m; polyacrylic ruber, solid, colourless; HD-70 plasticizer; pure lexitin; pure TDI; pure DPA 2.1.2 Equipments - Casting mould; - Planetary machine under vacuum; - Pyrometer; - High speech camera Phantom v711; - REAL software, Version 3.5; - Vaccum Stabil Tester; - Impact sensitive equipment – Cast; - Ballistic mortar; - Brookfield Viscometer DW-E; - M350-10CT Testometric; - Pyris TGA Thermogravimetric Analyzer ; - DEWE-3020 series PC instrument; - Piezoelectric pressure Sensor 6233AA0250 ; - Detonation calorimeter DCA-5; - TriStar II Micromeritics; - JSM-6510LV Series Scanning Electron 2.3 Research method and using technique 2.3.1 Method and technique of sample preparation The main technical steps: - Dry RDX, AP; - Quantitative weigh; - Liquid-component mixture; - Addition Al powder, mix well; - Addition RDX, mix well; - Addition AP powder, mix well; - Casting sample: + Taking mould; + Pour mixture into the mould, using baseball for being evenly; + Take baseball out; Fig 2.1 Mould for casting + Fit cushion, knot; sample + Cover lid, tighten; Lid Cushion - Dry for cross-linking process; Mould Outer cushion - Take sample out, test; Baseball Knot - Preservation of sample 2.3.2 Method and technique for measuring ∆P Itc 2.3.3 Testing in technical features of sample - VST, DSC methods; - IR, SEM, EDX, EDX-Mapping spectrum; - Surface area analysis BET 2.3.4 Testing in physical-mechnical features of sample - Compressible ability; - Dynamic viscosity 2.3.5 Testing in energy features of sample - Temperature of explosion; - Dimension of fireball; - Power 2.3.6 Testing in DNA-7V warhead - Measure Pmax Itc; - Dimension of fireball; - Blockhouse destructive test Chapter RESULT AND DICUSSION 3.1 Study on measurement of power parameters of TBE 3.1.1 Selection of diagrams From advantages and disvantages of testing diagrams as open, semiclosed and closed area, the thesis selects diagram of open area Testing diagram as Fig 3.1 Fig 3.1 Testing diagram of TBE sample 3.1.2 Results of measurement of ΔPmax Itc Use TBE-N2 sample (Russian), dimension:  55  91,2 mm; 413,6 g in mass; 1,91 g/cm3 in density Fig 3.2 shows P(t) diagrams of TBE-N2 sample at the distance of m, m, m m Fig 3.2 P(t) diagrams of explosion of sample TBE-N2 at different distances From Fig 3.2, value of ΔPmax and Itc are determined in table 3.1 Table 3.1 Value of ΔPmax and Itc of TBE-N2 Distance ΔPmax, psi Itc, psi.ms 3m 8.87 6.32 5m 3.89 3.74 7m 2.36 3.94 9m 1.71 3.61 Compare to value of Pmax and Itc of secondary explosive, thesis measures two samples named TNT and TG-30 (30% of TNT and 70% of RDX by mass) at the same mass Table 3.2 gives result of Pmax Itc of two those samples and TBE-N2 Table 3.2 Results of Pmax and Itc of three samples Sample Distance of 3m ΔPmax, Itc, psi psi.ms Distance of 5m ΔPmax, Itc, psi psi.ms Distance of 7m ΔPmax, Itc, psi psi.ms Distance of 9m ΔPmax, Itc, psi psi.ms TNT 7.51 4.86 3.26 3.21 2.12 3.52 1.52 3.35 TG-30 8.21 5.35 3.49 3.37 2.21 3.65 1.63 3.38 TBE-N2 8.87 6.32 3.89 3.74 2.36 3.94 1.71 3.61 Comment: Value of Pmax and Itc of TBE-N2 are bigger so much those value of TNT and TG-30, especially at the distance of m and m At far distance (7 m and m), the values of Pmax are affected by reflex wave and results is wrong Therefore, two value of Pmax and Itc at distance m and m can be used as main figures of the power of TBE 3.2 Study on selecting of components of TBE 3.2.1 Study on selecting of binder polymer 3.2.1.1 Evaluate of chemical compatibility of polymers and other component through VST method Three polymes used for evaluating of chemical compatibility are polymer polyacrylate (PAC), CKH-10KTP and epoxy ED-20 Value of VR of three polymers are 1.4 mL; 0.6 mL and 6.2 mL respectivelly Comment: According to standard STANAG 4147, epoxy ED-20 is not compatible with main components of TBE Two polymers PAC and CKH10 KTP are compatible with main components of TBE and compatible ability of CKH-10 KTP is higher than that of PAC 3.2.1.2 Select binder by characteristics of technology From result in table 3.1, when using binder based polymer CKH-10KTP, in case of having Pmax and Itc are suitable, component of TBE must include 35% of RDX, 25% of Al powder, 32% of AP and 9% of binder From dynamic viscosity (), it is said that status of mixture can be suitable with other technical method for stuffing Detail values of  are given: - 102 to 103 (maximum 6.103) pa.s: free casting; - 103 to 105 pa.s: casting with pressure; - 106 to 1011: compression The value of  of TBE based on CKH-10KTP is 7,3.105 pa.s It is believed that only using compression method for this mixture The last aim of studing on TBE is to stuff this explosive into DNA-7V warhead The parts of head and tail of this warhead are smaller than the middle part, so optimal method to stuff TBE into warhead is casting one The TBE based on ruber CKH-10KTP is not suitable with DNA-7V warhead With rubber PAC, the thesis studies two sample named TBE-V6 and TBE-V7 with component is showed in table 3.5 Table 3.5 The rate of component of two sample TBE Component Rate (%) TBE-V6 TBE-V7 RDX 23 25 Al powder 29 27 AP 32 33 Binder based on PAC 16 15 The value of dynamic viscosity of TBE-V1 and TBE-V2 are 45,826 Pa.s 53,482 Pa.s respectively Comment: TBE based on PAC fit DNA-7V because of characteristic of technology Futhermore, PAC meets the chemical compatibility through VST test 3.2.1.3 Evaluate compatibility of PAC and mixture by DSC method Using DSC method to determine the level of compatibility PAC and main components of TBE Selected sample for experiment is TBE-V8 From DSC diagram of PAC and sample TBE-V8 The value of ΔPp is 3.5 o C According to standard STANAG 4147, PAC and mixture of Al, AP, RDX are comparatible 3.2.1.4 Study on abiliy of cure of binder based on polymer PAC From fig 3.7, it can be clearly seen that emerging wave number of following functional groups: hidroxyl, C-H link in hydrocarbon, cacbonyl, oscillating of C-O link Fig 3.7 IR spectrum of PAC Hình 3.8 IR spectrum of PAC cured From fig 3.8, it is showed that having groups, links: C-H link in alkanes, isocyanat groups, weak carbonyl groups (because isocyanat groups exceed), CH2 groups in benzene, oscillating of C-O link Hydroxyl group no longer exists due to joining to cured reaction Comment: When curing PAC by TDI, the existence of reaction of isocyanat groups and hydroxyl creates cross-linking polymer that has adhesive ability of solid components 3.2.1.5 Study on linking ability of binder and materials Using BET method for measurement of specific surface (SR) of materials, results as: - RDX explosive: SR = 0,11 (m2/g); - Amonium perchlorate: SR = 0,19 (m2/g); - Al power: With three particle sizes:  m (i),  45 m (ii),  75 m (iii), the value of SR are 6,35 (m2/g); 0,73 (m2/g) 0,39 (m2/g) respectively a b Fig 3.9 SEM images of RDX (a), mixture of RDX and binder (b) Comment: From fig 3.9 and 3.10, it is showed that having a little of AP and RDX powders are covered by binder due to small specific surface Specific surface of Al powders (i) are much larger than that of Al powders (ii) and (iii), so binder is absorbed and kept on surface of Al powders a b Fig 3.10 SEM images of AP (a), mixture of AP and binder (b) a b Fig 3.11 SEM images of Al powder (a), mixture of Al and binder (b) Comment: Binder covered Al powders (i) well in mixture For this reason, mechanical durability of TBE made from Al powders (i) is higher that from Al (ii) Al (iii) powders 3.2.1.6 Study on ability of plasticity of plasticizer mixtures Binder mixtures include: 25% of PAC; 52,5% of DEGDN and 22,5% of TEGDN (plasticizer mixture HD-70) by mass Using DSC method for this study Fig 3.15 DSC diagram of PAC Fig 3.16 Glass transition temperature of PAC after plasticity 12 process of oxidizer creates hot gases to support the burning of Al Amount of gases of decomposition of NH4NO3 is the biggest and that of NaNO3 is the smallest However, NH4NO3 is not used as oxidizer in TBE because it absorbs humidity so strongly - Comparison of resutls of TBE-V21, TBE-V22 and comparative sample shows that TBE-V16 sample has the highest results, TBE-V22 has the lowest results The reason is because burning heat and burning rate of Al is the biggest when comparing to burning heat and burning rate of Mg and Al-Mg alloy From above study and domestic technology conditions, thesis selects AP and Al as main materials of TBE The optimal contain of TBE as table 3.15 Table 3.15 The optimal contain of TBE Order Contains Rate (%) by mass PAC HD-70 Lecithin TDI DPA Al 12.00 ± 0.10 4.00 ± 0005 0.30 ± 0.01 0.80 ± 0.03 0.40 ± 0.02 29.00 ± 0.50 RDX 24.50 ± 0.50 AP 29.00 ± 0.50 3.3 Study on a number of properties of explosive composition 3.3.1 Study of effect of material’ particle size on dynamic viscosity after mixture Particle size of materials as: - RDX: 0,09 mm to 0,5 mm - Al:  m,  45 m, and  75 m - AP: 100÷150 m 180÷280 m and 280÷450 m Dynamic viscosity of a number of compositions are given in table 3.16 Table 3.16 Dynamic viscosity of a number of compositions (Pa.s) Al powder  (i) AP Equipment can Equipment can not measure not measure 180 ÷ 280 () 53180   180 ÷ 280 () 44700   Comment: It is clear that Al (i) can use with all three of particle size of AP for casting method Effects of AP and Al into dynamic viscosity have Particle size (m) 100 ÷ 150 () 58440 Particle size (m)  45 (ii)  75 (iii) 13 opposite trends: particle size of AP increases lead to decrease’s dynamic viscosity, particle size of Al increases lead to increase’s dynamic viscosity The reason is due to chink between particle and good absorb characteristic of Al particles 3.3.2 Study on life period of composition 3.3.2.1 Study on life period of composition at room temperature Life period of composition is considered as the period of time that composition keeps the value of dynamic viscosity for casting method Using Al with particle size  m, AP Al with particle size from 180 to 280 m Value of dynamic viscosity at different times at room temperature, results are in fig 3.23 Fig 3.23 The change of dynamic viscosity follows time Comment: Life period of composition is about 5h at room temperature 3.3.2.2 Study of effect of temperature on composition‘s life period Using Al with particle size  m, AP Al with particle size from 180 to 280 m Value of dynamic viscosity at different times at temperature of 35 oC to 50 oC, results are in table 3.18 Thesis realizes that temperature have big effect on life period of composition This is important foundation as making a choice of technical method and designing equipment of casting TBE into warhead Table 3.18 Effect of temperature on life period of composition Temp (oC) Time 35 40 45 50 4h 25 3h 30 2h 15 35 Dynamic viscosity (Pa.s) Requirement of casting Results method under pressure 98741 102758 98382 103396 103÷105 14 3.4 Study of effects on the power of TBE 3.4.1 Study of effect of material’s particle size on ∆Pmax Itc 3.4.1.1 Study of effect of Al powder’s particle size on ∆Pmax Itc TBE samples: - TBE-V16 with Al has particle size  m; - TBE-V23 with Al has particle size  45 m; - TBE-V24 with Al has particle size  75 m Particle size is from 100 to150 m Results is in table 3.19 Table 3.19 The result of Pmax and Itc Sample TBE-V16 TBE-V23 TBE-V24 Itc, psi.ms Pmax, psi Distance of 3m Distance of 5m Distance of 3m Distance of 5m 3.72 5.98 3.64 8.71 8.53 6.14 3.89 3.78 5.82 8.58 3.65 4.07 Comment: There is not a clear difference between results, the reason is due to particle size of Al All three of Al powders is small which leads to complete burning process of Al in afterburning period 3.4.1.2 Study of effect of AP powder’s particle size on ∆Pmax Itc TBE samples: - TBE-V16 with Al has particle size is from 100 to 150 m; - TBE-V25 with Al has particle size is from 150 to 280 m; - TBE-V26 with Al has particle size is from 280 to 450 m Particle size is  m Results is in table 3.20 Table 3.20 The result of Pmax and Itc Sample Itc, psi.ms Pmax, psi Distance of 3m Distance of 5m Distance of 3m Distance of 5m TBE-V16 8.71 3.72 5.98 3.64 TBE-V25 3.52 8.62 5.74 3.41 TBE-V26 3.28 8.46 5.36 3.27 Comment: Result of TBE-V16 is the biggest and result of TBE-V26 is the smallest, thus particle size of AP affect on the power of TBE The bigger particle size of AP is, the smaller the power of TBE is The reason is that AP has low temperature of ignition, so burning process of Al creates hot gases to support process of Al in afterburning period AP with small particle size reacts completely and Al also burn completely to create large amount of energy The core of AP with big particle size does not decompose completely in afterburning period, thus Al does not have enough hot environment for absolute burning 15 3.4.2 Study of effect of TBE sample’s density on ΔPmax Itc Using three TBE samples with different density: TBE-V16 has density of 1.91 g/cm3; TBE-V27 TBE-V28 have density 1.86 g/cm3 and 1.80 g/cm3 respectively Using Al with particle size of  m, AP with particle size of from 100 to 150 m for samples Results is in table 3.22 Table 3.22 The result of Pmax and Itc Sample Itc, psi.ms Pmax, psi Distance of 3m Distance of 5m Distance of 3m Distance of 5m TBE-V16 8.71 5.98 3.72 3.64 TBE-V27 8.57 5.82 3.63 3.55 TBE-V28 8.44 5.62 3.47 3.42 Comment: Following to trend of decrease of density, Pmax and Itc also decrease, TBE-V16 has the biggest result The source is because explosive heat is directly proportional to the density Moreover, explosive heat is directly proportional to Pmax, so Pmax is directly proportional to density This three samples has the same chemical contents, therefore the great value of Pmax leads to great value of Itc as well 3.4.3 Study of effect of diameter of TBE sample on ΔPmax Itc Using four TBE samples with different diameter: TBE-V16 has diameter of 5.5 cm; TBE-V29, TBE-V30, and TBE-V31 have daimeter of 3.4cm, 4.25cm, and 6.4 cm respectively Using Al with particle size of  m, AP with particle size of from 100 to 150 m for samples Results is in table 3.24 Table 3.24 The result of Pmax and Itc Sample Itc, psi.ms Pmax, psi Distance of 3m Distance of 5m Distance of 3m Distance of 5m TBE-V29 8.26 3.32 5.42 3.38 TBE-V30 3.57 8.44 5.76 3.61 TBE-V16 8.71 3.72 5.98 3.64 TBE-V31 9.02 4.07 6.32 3.96 Comment: The bigger the diameter of TBE is, the higher the value of Pmax and Itc are, TBE-V29 has the highest results This is due to the explosive concentration A parameter which is cared is ratio of leghth (L) and diameter (Ф) of samples: γ = L  TBE-V29 has “the most unbalenced” dimension, the leghth is much greater than diamenter (γ is the the greatest) In explosion, sample is ingitited in one side, 16 explosive energy is not distributed equally to directions from center of sample, so results of TBE-V29 is the smallest On the contrary, results of TBE-V31 is the greatest (γ is the smallest) Nevertheless, from references and reality of warheads’ dimension TBE-V16 sample with diameter of 5.5 cm, leghth of 9.0 to 9.4 cm is selected for study 3.4.4 Establisment of semi-practical equal for P Following to the semi-practical equal for P, thesis gives equal for P: P  9.81 37.48 37.32      R R2 R3 With above equal, the value of overpressure is caculated in case of 1≤ R ≤ 1015 m Comment: The main results of study in 3.4 as follows: - Al powder with particle size is smaller than 75 m does not affect to the power of TBE; - Particle size of AP is inversely proportional to the power of TBE; - Density of sample is directly proportional to the power of TBE; - As dimeter is near to length, the power of TBE sample is the greatest Neverthless, for being suitable with geometry figure, practical shape of warhead and the technology advance, TBE samples with diameter of 5.5 cm and leghth of from 9.0 cm to 9.4 cm are chosen; - Al and AP are suitable fuel and oxidizer for study on TBE used for DNA7V warhead; - Establishment of semi-practical equal of ΔP 3.5 Study on other energy characteristics of TBE 3.5.1 Build on relationship between density and heat of explosion 3.5.1.1 Caculation of theory density Apply equal of theory density to composition Content for caculation is optimal in table 3.15 and follow density of contents, the value of theory density of sample is caculated as: 0.12 0.4 0.03 0.08 0.04 0.29 0.245 0.29          0,5143 t 1.5 1.33 1.08 1.2 1.2 2.7 1.81 1.95 Find out t = 1.95 (g/cm3) This figure is able to consider as the maximum of density of sample 3.5.1.2 Build on relationship between density and heat of explosion Using TBE-V16 sample (density of 1.91 g/cm3) and three TBE samples with different density Results of heat of explosion are given in table 3.27 17 The relationship between heat of explosion and density is showed clearly on graph 3.24 Table 3.27 Results of heat of explosion Sample Density (g/cm3) Heat of explosion (cal/g) TBE-V32 1.30 TBE-V33 TBE-V34 TBE-V16 1.47 1.55 1.91 1996 2106 2218 2416 Fig 3.24 The relationship between density and heat of explosion Comment: That relationship is a first-class linear funtion with regression line is y = 689.75 x + 1109.7 For the value of theory density t = 1.95 (g/cm3), the heat of explosion is 2454 cal/g This value is able to consider as the maimum of heat of explosive of TBE in experiment 3.5.2 Study on measure of detonation temperature of TBE 3.5.2.1 Measure of temperature of conventional explosives The pyrometer is a initial domestic product, and has not been inspectied yet Therefore, thesis use two kind of secondary explosive that has known detonation temperature as TNT and TG (composition of TNT and RDX) for testing equipment Two samples are done by casting method with the same of mass of TBE Result of measure of detonation temperature is showed in graph T(t), (ventical - temperature, K, horizontal - time, second) T(t) graph of TNT sample is given in table 3.25, and of TG is given on table 3.26 18 Fig 3.25 Graph T(t) of TNT explosion Fig 3.26 Graph T(t) of TG explosion Comment: Detonation temperature of TNT is about 3500 K and of RDX is about 3730 K Results is suitable with figures on the references Hence, results from pyrometer is belivable, pyrometer is able to use for measure of other explosives 3.5.2.2 Measure of detonation temperature of TBE Result is showed on graph 3.27 Fig 3.28 Image of fireball of TBE Comment: Detonation process of TBE includes two period: explosion and afterburning, happens in long time Maximum temperature of TBE explosion (about 3700 K) is detonation temperature of RDX, burning temperature which is from 2100 K to 2200 K is burning temperature of Al powder Period of afterburing is about 30 ms So far, published studies world wide on TBE show that TBE explosion has period of afterburning Neverthless, there has had any study which quantity of period of afterburning Figures and method of thesis confirm that having period of afterburning and quantify this period of TBE 3.5.3 Study on measure of dimension of fireball of TBE explosion Using high speed camera to record detonation process and to realize the time fireball has maximum dimensions (fig 3.28) Compare of square of TNT, TG at the same mass Thesis realizes square of fireball of TBR is the Fig 3.27 Graph T(t) of TBE 19 biggest (30.5 m2) Hence, square of fireball is the parameter which is used to evaluate energy characteristic of TBE as well 3.6 Study on technical characteristic of TBE 3.6.1 Study on effect density to mechanical durability of TBE Mechanical durability is measured by compression tester TBE samples are prepared at three densities: 1.8 g/cm3 (TBE-V36); 1.85 g/cm3 (TBE-V37) 1.91 g/cm3 (TBE-V38); diameter of 20 mm, high of 40 mm Results is given on fig 3.29 Comment: mechanical durability of TBE is so low At density of 1.91 g/cm3, under force of 0.73 (MPa) intrinsic structure of sample is broken (TBEV38) The reason is due to main contains of TBE Within three main solid contains AP, Al, RDX, only Al has good adhesion with binder, so mechanical durability is not high Fig 3.29 Results of testing of deflection TBE-V36.1 TBE-V37.1 TBE-V38.1 TBE-V36.2 TBE-V37.2 TBE-V38.2 3.6.2 Measurement of impact sensitivity of TBE By cast method, impact sensitivity is  16% Compare to impact sensitivity of other explosives, thesis realizes: - The impact sensitivity of TBE is not much higher than that of TNT ( %) The reason is due to the high rate of binder which leads to either good cover solid powders (AP, Al, RDX) with binder or filling binder to chink in powders - The impact sensitivity of TBE is the same as the impact sensitivity of two kind of PBX (PBX-HP-8001, PBX-HP-8501) The reason is due to the their contains In both of TBE and PBX, the secondary explosive is RDX, the rate of binder and additive are the same 20 3.6.3 Measurement of chemical durability of TBE The chemical durability is measured by method of VST at condition of temperature of 100oC, time of 48h, result is 0.286 mL/g As comparing to RDX-based explosives, it is clear that chemical durability of TBE is lower than that of C4-VN and PBX The reason is that TBE is composition of a number of different of contains with different durability which leads to the lower level in chemical durability 3.7 Compare the power and energy characteristic of TBE and secondary explosives Compare TBE to secondary explosive at following figures: 3.7.1 Figures of ΔPmax and Itc Results of comparing TBE to TNT as follows: - For the value of ΔPmax: At distance of 3m, ΔPmax of TBE is much greater than ΔPmax of TNT (about 20%) At distance of 5m, ΔPmax of TBE is greater than ΔPmax of TNT (not much, about 10%) - For Itc: At both of distances, Itc of TBE is clearly greater than Itc of TNT, the average value is about 25% Results of comparing TBE to TG shows that: The value of ΔPmax of TBE at both of distance are not much greater that of TG (about 106%) Nevertheless, Itc of TBE is significantly greater than Itc of TG with average value is about 118 % 3.7.2 Figure of heat of detonation QV ( TBE ) 2140   2.1 ; At = 1.6 g/cm3: QV ( TNT ) 1010 at = 1.89 g/cm3: QV ( TBE ) QV ( TNT )  2416 1010  2.4 Comment: The heat of detonation of TBE is much greater than that of TNT Compare to heat of other secondary explosives at the same density 1.6 g/cm3 as tetryl (1240 kcal/kg), hexogen (1470 kcal/kg), thesis find out that heat of detonation of TBE is much greater than that of secondary explosives as well This is the important figure as comparing TBE to secondary explosives 3.7.3 Figure of detonation temperature Study at 3.5.2 find out that detonation time of conventional high explosive (TNT and TG) is smaller ms, detonation process of TBE is able to divided into two stages Afterburning stage which lasts to 40 ms happens at burning temperature of Al (2100 ÷ 2200 K) Effect of TBE represents formation of a 21 enomous vacuum area in a long time which wipes out living being because of not being enough oxygen for keeping alive 3.7.4 Figure of square of fireball Study in table 3.30 finds out that the square of fireball of TBE is much greater than that of TNT and TG, results as follows: Se ( TBE ) 30.5 Se ( TBE ) 30.5   1.8 ;   1.3 Se( TNT ) 15.5 Se( TG ) 24.5 Comment: Content of TBE is different from contain of other high explosive which leads to diffrent mechanism of detonation as well Method of measurement of the power of explosive as the ballistic mortar used in Vietnam does not reflect the advantages of TBE Through studing of foreign conutries, practical condition in Vietnam, thesis gives the list of figures named Pmax, Itc, Se, Qv and detonation temperature Among them, Pmax and Itc play a vital role in evaluating the power of TBE As comparing to Pmax and Itc of conventional high explosive, Pmax and Itc of TBE is much greater and show the essence of TBE 3.8 Study on producing and testing DNA-7V warhead 3.8.1 Study on finding out about TBE casting method The major requirement of casting TBE is high density (1.89 g/cm3) In Vietnam, there is not any explosive products yet which get this density High density is main difficulty which thesis faces in process of finding out technology By analysis and evaluation, the method of casting under vacuum pressure is found out 3.8.2 Study on designing, producting casting equipment 3.8.2.1 Calculation of volume of casting jar With the mass of TBE given into the jar is about 2800 g, real density of composition is near to 1.70 g/cm3 It means that the maximum volume of TBE is close to 1450 cm3 Moreover, it is nessessary to have space for direction of piston Thesis choose this space with volume is a haft of volume of explosive Dimensions of chosen jar as follows: 130mm in diameter, 165mm in length, 2190 cm3 in volume 3.8.2.2 Calculation of thick of casting jar SUS 304 steel is chosen as material of jar for avoiding sparks appeared by impacting of parts of equipment Suppose maximum working pressure in jar is 120 atm (safe limited level of equipment) From equal of durability, finding out that the jar which has 9mm in thick is able to be durable at high pressure environment 22 3.8.2.3 Technical characteristic of equipment Producted equipment has 27 parts (fig 3.34) The main technical characteristics: maximum capacity: 3.0 kg/batch, working prassure (3545) atm, maximum working length of cylinder: 120 mm, level of vacuum: -450 mmHg, total weight: 120 kg a b Fig 3.34 Producted Fig 3.36 A DNA-7V warhead without TBE (a) equipment and a perfected warhead (b) 3.8.4 Manufacture product Apply technology process for manufacturing product with casting equipment (fig 3.34), DNA-7V warheads are casted successfully (fig 3.36) By testing on weigh and density of ten DNA-7V warheads, results meet requirements, TBE has good quality without any mistake Test on distribution of element in components by EDX-Mapping method It is clearly seen that elements as Al, C, O, Cl, N are distributied equally in TBE sample Therefore, technological parameters of process of TBE casting into warhead DNA-7V is reasonable 3.8.5 Results of testing on DNA-7V 3.8.5.1 Result of testing on Pmax and Itc Results of Pmax and Itc are given in table 3.40 Table 3.40 Results of Pmax and Itc Order YCKT Itc (psi.ms) Pmax (psi) Distance of 6m Distance of 10m Distance of 6m Distance of 10m 7.12 7.07 7.74 ≥ 6.68 9.79 9.49 9.55 ≥ 9.38 3.31 3.28 3.18 ≥ 3.02 6.26 6.80 6.11 ≥ 5.02 23 3.8.5.2 Measure dimension of fireball Results of measurement of dimension of fireball are given in table 3.41 Table 3.41 Results of dimension of fireball Dimension of fireball Order YCKT Dhorizontal (m) Dventical (m) Square (m2) 6.8 7.2 6.8 ≥ 6.5 4.8 4.4 4.4 ≥ 4.3 32.6 31.7 29.9  28 3.8.5.3 Test on destructive blockhouse b a Fig 3.40 Imagine of blockhouse after destructive test a Before test b After test Testing condition: warhead is placed in the middle of blockhouse, using remote ignition Testing results: 03/03 blockhouses are distroyed completely, fig 3.40 b gives imagine of a destroyed blockhouse Comment: apply of studies to manufacturing TBE and DNA-7V warhead leads to suitable results This is a important premise for manufacturing DNA7V in Vietnam CONCLUSION Outcomes: Choosing of domestic evaluation method of power of TBE through two parameters named ΔPmax and Itc Determination of optimal component of TBE for DNA-7V warhead incluses 24,5% of RDX; 29% of Al; 29% of AP; 17,5% of others) Study on applying of pyrometer for measurement of temperature and also quantifying afterburning period of the TBE explosion (about 40 ms) Measuring dimension (3.6m × 2.7m) and square of fireball of TBE (30.5 m2) 24 Evaluate technical characteristic of TBE, results show that TBE has so high chemical durability (0.286 mL), low mechanical durability (0.73 MPa) and low impact sensitively (≤ 16 %) Study on producing equipment and giving technical process for casting TBE into DNA-7V warhead in the first step New contributions: Making scientific basic about thermobaric explosive (TBE) clearly, choosing of domestic evaluation method of power of TBE through two parameters named ΔPmax and Itc Thesis uses pyrometer for measurement of temperature and also quantifies afterburning period of the TBE explosion Determination of optimal component of TBE for DNA-7V warhead (24,5 % of RDX; 29 % of Al; 29 % of AP; 17,5 % of others) Giving technical process for casting TBE into DNA-7V warhead in the first step Next study: Study on effect of the rate of different particle size of Al powder on dynamic viscisity which leads to the ratio of small particle size of Al Study on comparing the power of TBE to the power of aluminized explosives Study on perfecting technology for casting TBE into DNA-7V warhead THE SCIENTIFIC PUBLICATIONS Tran Quang Phat, Ngo Van Giao, Ninh Duc Ha, Nguyen Khac Phuong Hoa (2017), “Several initial results of research into thermobaric compositions in Vietnam”, The 5th Academic conference on natural science for young scientists, master and Ph.D students from Asean countries, Publishing House for Science and Technology, pp 219-225 Tran Quang Phat, Ngo Van Giao, Ninh Duc Ha, Nguyen Mau Vuong, Hoang Van Quyen (8/2018), “Study on designing equipment for casting thermobaric explosive into DNA-7V warhead”, Journal of Military Science and Technology, FEE Special Issue, pp 302-308 Tran Quang Phat, Ngo Van Giao, Ninh Duc Ha, Hoang Van Quyen, Nguyen Minh Tuan, Pham Van Duong (2/2019), “Study on synthesis technology of TEGDN explosive”, Journal of Military Science and Technology, 59, pp 127-134 Tran Quang Phat, Ngo Van Giao, Ninh Duc Ha, Truong Dinh Dao, Vu Tai Tu (8/2019), “Study on selecting method of evaluating the power of thermobaric explosives”, Journal of Military Science and Technology, 62, pp 102-109 Tran Quang Phat, Ngo Van Giao, Ninh Duc Ha, (10/2019), “Study of effect of the rate of ingredients on parameters ΔPmax and Itc of thermobaric explosive used for shell ĐNA-7V”, Journal of Military Science and Technology, FEE Special Issue, pp 351-356 ... studies to manufacturing TBE and DNA -7V warhead leads to suitable results This is a important premise for manufacturing DNA7V in Vietnam CONCLUSION Outcomes: Choosing of domestic evaluation method... diameter of 5.5 cm and leghth of from 9.0 cm to 9.4 cm are chosen; - Al and AP are suitable fuel and oxidizer for study on TBE used for DNA7V warhead; - Establishment of semi-practical equal of ΔP... is nessessary to have space for direction of piston Thesis choose this space with volume is a haft of volume of explosive Dimensions of chosen jar as follows: 130mm in diameter, 165mm in length,