Yang Qin, Jie Liu, Jiangbao Zeng, Jinbin Zou, Ye Song, Fengsheng Li
To improve the ignition and combustion performance of boron (B), the B@ potassium perchlorate (KP) composite micro‐units are successfully prepared by recrystallization of solvent evaporation. The morphology and structural composition show that B@KP composite micro‐units are formed by the gentle recrystallization of KP at the heterogeneous interface between B particles and solvents. It is shown by thermal analysis that the initial thermal decomposition temperature of KP is reduced by 49 °C due to the reduction of particle size. In addition, the heat of 420 J/g released by the thermal decomposition of KP is beneficial to the evaporation of the oxide boron (B2O3) film on the surface of B, which reduces the initial oxidation temperature of B by 185 °C and improves the ignition performance of B. Interestingly, the oxygen (O2) released by the thermal decomposition of KP quickly reacts with B to release heat of 3608 J/g, which improves the combustion performance of B. The optimal mass ratio of B to KP is 1: 5, which results in the ignition delay time of 641 ms, a reduction of 19 ms compared to the physical mixed sample. The ignition delay times of other samples are 724 ms, 680 ms and 650 ms respectively, and B could not be ignited successfully. In the combustion process, all samples emit a bright green flame of B combustion, and even a fierce combustion flame like a mushroom cloud appears. In a word, the B@KP composite micro‐units have great potential for application in solid propellants.
为改善硼（B）的点火和燃烧性能，通过溶剂蒸发重结晶成功制备了 B@ 高氯酸钾（KP）复合微单元。形态和结构组成表明，B@KP 复合微单元是由 KP 在 B 颗粒与溶剂的异质界面上温和重结晶形成的。热分析表明，由于粒径的减小，KP 的初始热分解温度降低了 49 ℃。此外，KP 热分解释放的 420 J/g 热量有利于 B 表面氧化硼（B2O3）膜的蒸发，从而使 B 的初始氧化温度降低了 185 ℃，改善了 B 的点火性能。有趣的是，KP 受热分解释放出的氧气（O2）迅速与 B 发生反应，释放出 3608 J/g 的热量，从而改善了 B 的燃烧性能。B 与 KP 的最佳质量比为 1:5，这使得点火延迟时间为 641 毫秒，与物理混合样品相比缩短了 19 毫秒。其他样品的点火延迟时间分别为 724 毫秒、680 毫秒和 650 毫秒，B 无法成功点火。在燃烧过程中，所有样品都发出了明亮的绿色 B 燃烧火焰，甚至出现了像蘑菇云一样的猛烈燃烧火焰。总之，B@KP 复合微单元在固体推进剂中具有很大的应用潜力。
{"title":"Preparation and characteristics of boron‐based composite micro‐units encapsulated by potassium perchlorate","authors":"Yang Qin, Jie Liu, Jiangbao Zeng, Jinbin Zou, Ye Song, Fengsheng Li","doi":"10.1002/prep.202400122","DOIUrl":"https://doi.org/10.1002/prep.202400122","url":null,"abstract":"To improve the ignition and combustion performance of boron (B), the B@ potassium perchlorate (KP) composite micro‐units are successfully prepared by recrystallization of solvent evaporation. The morphology and structural composition show that B@KP composite micro‐units are formed by the gentle recrystallization of KP at the heterogeneous interface between B particles and solvents. It is shown by thermal analysis that the initial thermal decomposition temperature of KP is reduced by 49 °C due to the reduction of particle size. In addition, the heat of 420 J/g released by the thermal decomposition of KP is beneficial to the evaporation of the oxide boron (B<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>) film on the surface of B, which reduces the initial oxidation temperature of B by 185 °C and improves the ignition performance of B. Interestingly, the oxygen (O<jats:sub>2</jats:sub>) released by the thermal decomposition of KP quickly reacts with B to release heat of 3608 J/g, which improves the combustion performance of B. The optimal mass ratio of B to KP is 1: 5, which results in the ignition delay time of 641 ms, a reduction of 19 ms compared to the physical mixed sample. The ignition delay times of other samples are 724 ms, 680 ms and 650 ms respectively, and B could not be ignited successfully. In the combustion process, all samples emit a bright green flame of B combustion, and even a fierce combustion flame like a mushroom cloud appears. In a word, the B@KP composite micro‐units have great potential for application in solid propellants.","PeriodicalId":20800,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":"30 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141933279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yi‐min Luo, Yu Xia, Jun‐hong Wang, Teng Ma, Zhang‐qi Feng, Sen Xu, Xing‐liang Wu
Burning rate suppressants (BRSs) refer to a series of additives that reduce the burning rate of propellants, crucial for achieving sustained and stable thrust. This research focuses on assessing the impact of ammonium sulfate and ammonium oxalate on thermal stability and their potential as BRSs. Due to the stronger inhibitory effect of ammonium sulfate on the AP proton transfer process, the activation energy of propellant's first decomposition can be increased from 94.71 kJ mol−1 to 129.69 kJ mol−1 at a 3 % addition level. Based on Semenov model, the self‐accelerated decomposition temperatures (TSADT) were calculated and validated through 7‐day isothermal test. Introducing ammonium sulfate and ammonium oxalate raised the TSADT from 197.31 °C to 220.90 °C and 215.06 °C, respectively, deviating less than 4 % from experimental results. Among the propellants tested, those with ammonium sulfate showed prolonged response delay times (44.43–33.60 h), lower superheating temperatures (222.8–445.5 °C), and reduced mass loss rates (33.0–71.4 %) after 7 days of isothermal storage at 220–240 °C. The consistency between thermal analysis and isothermal test underscores the significant impact of activation energy on thermal stability.
{"title":"Analysis of thermal stability for slow burning propellant based on isothermal testing: Self‐accelerating decomposition temperature (SADT) calculation and validation","authors":"Yi‐min Luo, Yu Xia, Jun‐hong Wang, Teng Ma, Zhang‐qi Feng, Sen Xu, Xing‐liang Wu","doi":"10.1002/prep.202400071","DOIUrl":"https://doi.org/10.1002/prep.202400071","url":null,"abstract":"Burning rate suppressants (BRSs) refer to a series of additives that reduce the burning rate of propellants, crucial for achieving sustained and stable thrust. This research focuses on assessing the impact of ammonium sulfate and ammonium oxalate on thermal stability and their potential as BRSs. Due to the stronger inhibitory effect of ammonium sulfate on the AP proton transfer process, the activation energy of propellant's first decomposition can be increased from 94.71 kJ mol<jats:sup>−1</jats:sup> to 129.69 kJ mol<jats:sup>−1</jats:sup> at a 3 % addition level. Based on Semenov model, the self‐accelerated decomposition temperatures (TSADT) were calculated and validated through 7‐day isothermal test. Introducing ammonium sulfate and ammonium oxalate raised the TSADT from 197.31 °C to 220.90 °C and 215.06 °C, respectively, deviating less than 4 % from experimental results. Among the propellants tested, those with ammonium sulfate showed prolonged response delay times (44.43–33.60 h), lower superheating temperatures (222.8–445.5 °C), and reduced mass loss rates (33.0–71.4 %) after 7 days of isothermal storage at 220–240 °C. The consistency between thermal analysis and isothermal test underscores the significant impact of activation energy on thermal stability.","PeriodicalId":20800,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":"15 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141933153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ying Zhang, An Li, Denan Kong, Huanjing Li, Xianshuang Wang, Yuheng Shan, Yage He, Yeping Ren, Lixiang Zhong, Wei Guo, Fanzhi Yang, Yao Zhou, Min Xia, Ruibin Liu
It is highly desirable to actively modulate the explosive performance and sensitivity of traditional explosives, such as RDX (hexahydro‐1,3,5‐trinitro‐1,3,5‐triazine), and HMX (cyclotetramethylene tetranitramine), especially to reduce their explosive power and electrostatic sensitivity. Herein, a new avenue is found to effectively modulate the explosive performance and electrostatic sensitivity by direct irradiation of high‐density X‐ray from synchrotron radiation. RDX as a kind of popular and high‐performance explosive, is chosen to demonstrate the modulated effectiveness. After X‐ray irradiation with different irradiation time, the detonation velocity (DV), detonation pressure (DP), heat of detonation (HoD), and electrostatic sensitivity of RDX are determined. Compared with the electrostatic sensitivity and explosive parameters of original high‐quality RDX, the maximum electrostatic sensitivity value is increased to 1061 mJ after irradiation, which is an enhancement ratio of 39.61 %. The lowest DV is 7.57 km/s (−14.27 %), the lowest DP is 16.23 GPa (−53.20 %), and the lowest HoD is 5.15 kJ/g (−9.65 %). These changes mainly originate from the changes in the structure and crystal structure of RDX molecules after irradiation, as evaluated by Scanning Electron Microscope (SEM), X‐ray Diffraction (XRD), and X‐ray Photoelectron Spectroscopy (XPS). The mechanism of RDX modulation by X‐ray is due to denitrification, which always accompanies lots of energy releases, thus impacting the electrostatic sensitivity and explosive power of RDX. Therefore, this study not only provides a new method for reducing electrostatic sensitivity to improve the safety of storage, transportation, and application of RDX, but also holds great potential to reduce explosive performance by non‐contact means.
{"title":"Rapid modulation of electrostatic sensitivity and explosive performance by X‐ray radiation","authors":"Ying Zhang, An Li, Denan Kong, Huanjing Li, Xianshuang Wang, Yuheng Shan, Yage He, Yeping Ren, Lixiang Zhong, Wei Guo, Fanzhi Yang, Yao Zhou, Min Xia, Ruibin Liu","doi":"10.1002/prep.202300313","DOIUrl":"https://doi.org/10.1002/prep.202300313","url":null,"abstract":"It is highly desirable to actively modulate the explosive performance and sensitivity of traditional explosives, such as RDX (hexahydro‐1,3,5‐trinitro‐1,3,5‐triazine), and HMX (cyclotetramethylene tetranitramine), especially to reduce their explosive power and electrostatic sensitivity. Herein, a new avenue is found to effectively modulate the explosive performance and electrostatic sensitivity by direct irradiation of high‐density X‐ray from synchrotron radiation. RDX as a kind of popular and high‐performance explosive, is chosen to demonstrate the modulated effectiveness. After X‐ray irradiation with different irradiation time, the detonation velocity (DV), detonation pressure (DP), heat of detonation (HoD), and electrostatic sensitivity of RDX are determined. Compared with the electrostatic sensitivity and explosive parameters of original high‐quality RDX, the maximum electrostatic sensitivity value is increased to 1061 mJ after irradiation, which is an enhancement ratio of 39.61 %. The lowest DV is 7.57 km/s (−14.27 %), the lowest DP is 16.23 GPa (−53.20 %), and the lowest HoD is 5.15 kJ/g (−9.65 %). These changes mainly originate from the changes in the structure and crystal structure of RDX molecules after irradiation, as evaluated by Scanning Electron Microscope (SEM), X‐ray Diffraction (XRD), and X‐ray Photoelectron Spectroscopy (XPS). The mechanism of RDX modulation by X‐ray is due to denitrification, which always accompanies lots of energy releases, thus impacting the electrostatic sensitivity and explosive power of RDX. Therefore, this study not only provides a new method for reducing electrostatic sensitivity to improve the safety of storage, transportation, and application of RDX, but also holds great potential to reduce explosive performance by non‐contact means.","PeriodicalId":20800,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":"22 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141933220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An improved method is presented for the prediction of detonation velocity of C−H−NO based pure, mixed, and aluminized explosives. The new empirical relation is based on calculated values of the heat of detonation and the number of moles of gaseous detonation products. A constant of the empirical relation has been found using regression analysis of 74 data points of pure and mixed explosives as well as 22 data points of aluminized explosives. The value of the constant is found to be 1.00 with R2 value of 0.96. Proposed empirical relation has been validated by comparing predicted values of detonation velocities with measured values for TNT, HMX/RDX‐TNT‐Al and HMX‐TNT based explosives. Experimental measurement of detonation velocity has been carried out using pin‐ionization method on cylindrical explosive charges of diameter 50 mm and height 150 mm. The predicted values of detonation velocities are in good agreement with measured values with a root mean square error of 1.28 %. The validation of the new relation has also been carried by comparing calculated values of detonation velocities using present and literature methods with reported experimental values.
{"title":"Improved method for prediction of detonation velocity for C−H−N−O based pure, mixed and aluminized explosives","authors":"Satveer Kumar, Devinder Mehta, Manish Kumar, Surinder Kumar, Pramod Kumar Soni","doi":"10.1002/prep.202400045","DOIUrl":"https://doi.org/10.1002/prep.202400045","url":null,"abstract":"An improved method is presented for the prediction of detonation velocity of C−H−NO based pure, mixed, and aluminized explosives. The new empirical relation is based on calculated values of the heat of detonation and the number of moles of gaseous detonation products. A constant of the empirical relation has been found using regression analysis of 74 data points of pure and mixed explosives as well as 22 data points of aluminized explosives. The value of the constant is found to be 1.00 with <jats:italic>R</jats:italic><jats:sup><jats:italic>2</jats:italic></jats:sup> value of 0.96. Proposed empirical relation has been validated by comparing predicted values of detonation velocities with measured values for TNT, HMX/RDX‐TNT‐Al and HMX‐TNT based explosives. Experimental measurement of detonation velocity has been carried out using pin‐ionization method on cylindrical explosive charges of diameter 50 mm and height 150 mm. The predicted values of detonation velocities are in good agreement with measured values with a root mean square error of 1.28 %. The validation of the new relation has also been carried by comparing calculated values of detonation velocities using present and literature methods with reported experimental values.","PeriodicalId":20800,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141933274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dong‐Mo Zhou, Bu‐Qing Hui, Shao‐Bin Zhao, Hang Chen, Xiang‐Yang Liu
To address the issue of randomness in the mechanical properties of the hydroxyl‐terminated polybutadiene (HTPB) propellant, a stochastic constitutive model (SCM) with a lognormally distributed random parameter Λ was proposed to describe their mechanical behaviors, and the structural integrity of a HTPB propellant grain was analyzed based on it. The results indicate that the stress‐strain curves predicted by the SCM have a good agreement with the experimental curves, and the experimental curves fall within a 95 % probability interval predicted by the SCM. The mechanical response of HTPB propellant grain under ignition pressurization is associated with the random parameters Λ. The maximum equivalent stress and safety factor increase approximately linearly with the increase of random parameters Λ, while the maximum equivalent strain and maximum damage coefficient decrease approximately linearly with the increase of random parameters Λ. The error in the mechanical response of the grain obtained based on the SCM and the experimental constitutive model is basically not more than 2 %, the SCM can effectively characterize the randomness in the mechanical response of propellant grain caused by the dispersion of HTPB propellant mechanical properties.
{"title":"A stochastic constitutive model and its application to HTPB propellant","authors":"Dong‐Mo Zhou, Bu‐Qing Hui, Shao‐Bin Zhao, Hang Chen, Xiang‐Yang Liu","doi":"10.1002/prep.202400008","DOIUrl":"https://doi.org/10.1002/prep.202400008","url":null,"abstract":"To address the issue of randomness in the mechanical properties of the hydroxyl‐terminated polybutadiene (HTPB) propellant, a stochastic constitutive model (SCM) with a lognormally distributed random parameter Λ was proposed to describe their mechanical behaviors, and the structural integrity of a HTPB propellant grain was analyzed based on it. The results indicate that the stress‐strain curves predicted by the SCM have a good agreement with the experimental curves, and the experimental curves fall within a 95 % probability interval predicted by the SCM. The mechanical response of HTPB propellant grain under ignition pressurization is associated with the random parameters Λ. The maximum equivalent stress and safety factor increase approximately linearly with the increase of random parameters Λ, while the maximum equivalent strain and maximum damage coefficient decrease approximately linearly with the increase of random parameters Λ. The error in the mechanical response of the grain obtained based on the SCM and the experimental constitutive model is basically not more than 2 %, the SCM can effectively characterize the randomness in the mechanical response of propellant grain caused by the dispersion of HTPB propellant mechanical properties.","PeriodicalId":20800,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":"78 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141933158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to investigate the mechanical formation, the mechanical‐thermo coupling mesoscale mechanism and the corresponding energy release characteristics of PTFE/Al composite material reactive jet, a mesoscale discretization model of PTFE/Al reactive liner with a mass ratio of 73.5 %/26.5 % is developed on the basis of the random delivery principle. The mesoscale numerical simulation is used to perform PTFE/Al reactive jet formation, obtaining the relative distribution characteristics of material, pressure, and temperature. The overpressure experiments for the energy release of reactive jets are conducted. The results show that there is an increasing tendency in the amount of Al particles from the jet's tip to its tail due to the velocity variance between PTFE and Al. The high temperature zones are found to be concentrated on the tip and axis of the jet, with particle deformation, collision and friction in the reactive jet accounting for the temperature rise. Moreover, the Al particle size has a significantly influence on the particle distribution and the mechanical‐thermo coupling behavior in the reactive jet, and the decrease of particle size is beneficial to the chemical reaction among the components of the reactive jet. To be more specifically, under the conditions of Al particle size of 400 μm, 600 μm and 800 μm, the overpressure peaks of reactive jet in 13 L chamber are 3.32 MPa, 2.86 MPa and 2.61 MPa, respectively. The variation of the overpressure with Al particle size obtained by experiment is consistent with the analysis of the mechanical‐thermo coupling characteristics of mesoscale numerical simulation.
{"title":"Mesoscale formation and energy release characteristics of PTFE/Al reactive jet","authors":"Yuanfeng Zheng, Hongyu Zhang, Peiliang Li, Zhijian Zheng, Huanguo Guo","doi":"10.1002/prep.202300310","DOIUrl":"https://doi.org/10.1002/prep.202300310","url":null,"abstract":"In order to investigate the mechanical formation, the mechanical‐thermo coupling mesoscale mechanism and the corresponding energy release characteristics of PTFE/Al composite material reactive jet, a mesoscale discretization model of PTFE/Al reactive liner with a mass ratio of 73.5 %/26.5 % is developed on the basis of the random delivery principle. The mesoscale numerical simulation is used to perform PTFE/Al reactive jet formation, obtaining the relative distribution characteristics of material, pressure, and temperature. The overpressure experiments for the energy release of reactive jets are conducted. The results show that there is an increasing tendency in the amount of Al particles from the jet's tip to its tail due to the velocity variance between PTFE and Al. The high temperature zones are found to be concentrated on the tip and axis of the jet, with particle deformation, collision and friction in the reactive jet accounting for the temperature rise. Moreover, the Al particle size has a significantly influence on the particle distribution and the mechanical‐thermo coupling behavior in the reactive jet, and the decrease of particle size is beneficial to the chemical reaction among the components of the reactive jet. To be more specifically, under the conditions of Al particle size of 400 μm, 600 μm and 800 μm, the overpressure peaks of reactive jet in 13 L chamber are 3.32 MPa, 2.86 MPa and 2.61 MPa, respectively. The variation of the overpressure with Al particle size obtained by experiment is consistent with the analysis of the mechanical‐thermo coupling characteristics of mesoscale numerical simulation.","PeriodicalId":20800,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":"19 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141933271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A novel experimental setup, utilizing 3D Digital Image Correlation (3D‐DIC), is employed to characterize the mechanical behaviour of composite solid propellant (CSP) under uniaxial compression at three displacement rates (1, 7, and 50 mm/min). At larger deformation, 3D‐DIC consistently shows smaller strains than nominal strain values, and this difference increases with deformation across all the displacement rates. Displacement rates significantly affect the non‐linear stress‐strain response of the CSPs. After the completion of the compression test, the specimen is unloaded, and the lengths of the unloaded specimens measured after 24 hour indicate a recovery of 90–94 % of the original length of the specimens. The recovered length increases with an increase in the displacement rate. Initially, Poisson's ratio is close to 0.5, and dilatation is zero, indicating an incompressible behaviour. However, both Poisson's ratio and dilatation increase with an increase in longitudinal strain, indicating a transition to compressible behaviour. Comparing the scanning electron microscope (SEM) micrographs of the virgin and compressive‐loaded samples, noticeable debonding is observed at the matrix‐particle interfaces.
{"title":"3D‐DIC for mechanical characterization of composite solid propellant under uniaxial compression","authors":"Rajeev Ranjan, H. Murthy","doi":"10.1002/prep.202400084","DOIUrl":"https://doi.org/10.1002/prep.202400084","url":null,"abstract":"A novel experimental setup, utilizing 3D Digital Image Correlation (3D‐DIC), is employed to characterize the mechanical behaviour of composite solid propellant (CSP) under uniaxial compression at three displacement rates (1, 7, and 50 mm/min). At larger deformation, 3D‐DIC consistently shows smaller strains than nominal strain values, and this difference increases with deformation across all the displacement rates. Displacement rates significantly affect the non‐linear stress‐strain response of the CSPs. After the completion of the compression test, the specimen is unloaded, and the lengths of the unloaded specimens measured after 24 hour indicate a recovery of 90–94 % of the original length of the specimens. The recovered length increases with an increase in the displacement rate. Initially, Poisson's ratio is close to 0.5, and dilatation is zero, indicating an incompressible behaviour. However, both Poisson's ratio and dilatation increase with an increase in longitudinal strain, indicating a transition to compressible behaviour. Comparing the scanning electron microscope (SEM) micrographs of the virgin and compressive‐loaded samples, noticeable debonding is observed at the matrix‐particle interfaces.","PeriodicalId":20800,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":"53 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141885951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Robert T. Ichiyama, Madeleine Stanisha, Noah P. Scarpelli, James L. Smith, D. Scott Stewart, Jimmie C. Oxley
Simulations and experiments were conducted to control the shock‐to‐detonation transition by energy trapping in localized regions of nitromethane that contained arrays of embedded dense particles (tantalum rods). The localizations were additively manufactured and designed with simulations carried out with ALE3D, that used the ignition and growth reactive flow model for the explosive. Modelling demonstrated enhanced reactivity when the tantalum rods were present, leading to a detonation that otherwise did not occur for the same strength shock without rods. Experiments that confirmed predictions of the simulation were conducted using Fritz plane wave lenses to drive various input shocks into the system. Photon doppler velocimetry was the primary diagnostic used to measure shock input and reaction progression. These results suggest that it is possible design explosives to localize sensitivity to shock loading within an insensitive material increasing the overall safety of fielded energetic materials.
{"title":"Simulation and fabrication of reactive metamaterials for controllable energy response","authors":"Robert T. Ichiyama, Madeleine Stanisha, Noah P. Scarpelli, James L. Smith, D. Scott Stewart, Jimmie C. Oxley","doi":"10.1002/prep.202400132","DOIUrl":"https://doi.org/10.1002/prep.202400132","url":null,"abstract":"Simulations and experiments were conducted to control the shock‐to‐detonation transition by energy trapping in localized regions of nitromethane that contained arrays of embedded dense particles (tantalum rods). The localizations were additively manufactured and designed with simulations carried out with ALE3D, that used the ignition and growth reactive flow model for the explosive. Modelling demonstrated enhanced reactivity when the tantalum rods were present, leading to a detonation that otherwise did not occur for the same strength shock without rods. Experiments that confirmed predictions of the simulation were conducted using Fritz plane wave lenses to drive various input shocks into the system. Photon doppler velocimetry was the primary diagnostic used to measure shock input and reaction progression. These results suggest that it is possible design explosives to localize sensitivity to shock loading within an insensitive material increasing the overall safety of fielded energetic materials.","PeriodicalId":20800,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":"81 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141885953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Eliška Jehličková, Vojtěch Zůbek, Pavel Konečný, Karel Kubát
Combustible cartridge cases are parts of modular charges used in modern artillery systems. Some types of combustible cartridge case materials have exhibited problems during pyrostatic measurements caused by their difficult ignition. This article explores the possibility of testing the combustible cartridge case material mixed with a propellant of known ballistic properties and then separating the influence of that propellant using methods of mathematical analysis. The aim of this work is to create methodology for closed vessel tests of combustible cartridge case material. Outcome involves the characterization of combustible cartridge case material ballistic properties, including its burn rate parameters. Calculations described in this paper could potentially be modified to be applicable to other cases of mixture of two propellants.
{"title":"Combustible cartridge case material characteristics evaluation","authors":"Eliška Jehličková, Vojtěch Zůbek, Pavel Konečný, Karel Kubát","doi":"10.1002/prep.202400100","DOIUrl":"https://doi.org/10.1002/prep.202400100","url":null,"abstract":"Combustible cartridge cases are parts of modular charges used in modern artillery systems. Some types of combustible cartridge case materials have exhibited problems during pyrostatic measurements caused by their difficult ignition. This article explores the possibility of testing the combustible cartridge case material mixed with a propellant of known ballistic properties and then separating the influence of that propellant using methods of mathematical analysis. The aim of this work is to create methodology for closed vessel tests of combustible cartridge case material. Outcome involves the characterization of combustible cartridge case material ballistic properties, including its burn rate parameters. Calculations described in this paper could potentially be modified to be applicable to other cases of mixture of two propellants.","PeriodicalId":20800,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":"96 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141886103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aluminum powder is commonly used as a metal fuel additive in composite solid propellants. However, its tendency to agglomerate during combustion can lead to two‐phase flow losses, negatively impacting its energy performance. To address this issue and enhance the combustion performance of aluminum powder, nitrated graphene oxide (NGO) was developed to improve aluminum dispersion and optimize its energy characteristics. Various analytical techniques were employed to examine its properties, including Fourier‐transform infrared spectroscopy (FT‐IR), scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy (XPS), elemental analysis (EA), differential scanning calorimetry (DSC), and thermogravimetric analysis (TG). Al/NGO composite was prepared using a solution‐assisted method in N, N‐dimethylformamide (DMF) and characterized by SEM, XPS and X‐ray diffraction (XRD). The ignition characteristics and heat of combustion of Al/NGO powder were measured using a laser igniter and an oxygen bomb calorimetry. The appropriate mass ratios of NGO coating had positive effects on the ignition and combustion of Al. Specially, 4 % NGO coating reduced Al ignition energy by 46.5 % and increased the Al combustion efficiency by 22.0 %. Moreover, the catalytic effect of Al/NGO on the thermal decomposition of ammonium perchlorate (AP) was investigated using differential thermal analysis (DTA). Results showed that two‐stage pyrolysis paths of AP tended to merge into a single pyrolysis process when Al/NGO4 % was added. The most favorable catalytic effect on AP′s thermal decomposition process was produced with the addition of 10 % Al/NGO4 %, reducing the activation energy by Kissinger equation for high‐temperature decomposition to 107.7 kJ mol−1. These findings may provide valuable insight for enhancing the performance of aluminum powder in energetic materials through NGO modification.
{"title":"Preparation, characterization and thermal properties of nitrographene coated aluminum powder","authors":"Xiaoyong Ding, Yitong Fang, Ayimu Emu, Yidan Cao, Qiangqiang Liu, Baili Chen, Yingle Liu, Yingxin Tan","doi":"10.1002/prep.202300301","DOIUrl":"https://doi.org/10.1002/prep.202300301","url":null,"abstract":"Aluminum powder is commonly used as a metal fuel additive in composite solid propellants. However, its tendency to agglomerate during combustion can lead to two‐phase flow losses, negatively impacting its energy performance. To address this issue and enhance the combustion performance of aluminum powder, nitrated graphene oxide (NGO) was developed to improve aluminum dispersion and optimize its energy characteristics. Various analytical techniques were employed to examine its properties, including Fourier‐transform infrared spectroscopy (FT‐IR), scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy (XPS), elemental analysis (EA), differential scanning calorimetry (DSC), and thermogravimetric analysis (TG). Al/NGO composite was prepared using a solution‐assisted method in N, N‐dimethylformamide (DMF) and characterized by SEM, XPS and X‐ray diffraction (XRD). The ignition characteristics and heat of combustion of Al/NGO powder were measured using a laser igniter and an oxygen bomb calorimetry. The appropriate mass ratios of NGO coating had positive effects on the ignition and combustion of Al. Specially, 4 % NGO coating reduced Al ignition energy by 46.5 % and increased the Al combustion efficiency by 22.0 %. Moreover, the catalytic effect of Al/NGO on the thermal decomposition of ammonium perchlorate (AP) was investigated using differential thermal analysis (DTA). Results showed that two‐stage pyrolysis paths of AP tended to merge into a single pyrolysis process when Al/NGO<jats:sub>4 %</jats:sub> was added. The most favorable catalytic effect on AP′s thermal decomposition process was produced with the addition of 10 % Al/NGO<jats:sub>4 %</jats:sub>, reducing the activation energy by Kissinger equation for high‐temperature decomposition to 107.7 kJ mol<jats:sup>−1</jats:sup>. These findings may provide valuable insight for enhancing the performance of aluminum powder in energetic materials through NGO modification.","PeriodicalId":20800,"journal":{"name":"Propellants, Explosives, Pyrotechnics","volume":"190 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141886025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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