In this study, to meet the development and application requirements for high-strength and hightoughness energetic structural materials, a representative volume element of a TA15 matrix embedded with a TaZrNb sphere wa...In this study, to meet the development and application requirements for high-strength and hightoughness energetic structural materials, a representative volume element of a TA15 matrix embedded with a TaZrNb sphere was designed and fabricated via diffusion bonding. The mechanisms of the microstructural evolution of the TaZrNb/TA15 interface were investigated via SEM, EBSD, EDS, and XRD.Interface mechanical property tests and in-situ tensile tests were conducted on the sphere-containing structure, and an equivalent tensile-strength model was established for the structure. The results revealed that the TA15 titanium alloy and joint had high density and no pores or cracks. The thickness of the planar joint was approximately 50-60 μm. The average tensile and shear strengths were 767 MPa and 608 MPa, respectively. The thickness of the spherical joint was approximately 60 μm. The Zr and Nb elements in the joint diffused uniformly and formed strong bonds with Ti without forming intermetallic compounds. The interface exhibited submicron grain refinement and a concave-convex interlocking structure. The tensile fracture surface primarily exhibited intergranular fracture combined with some transgranular fracture, which constituted a quasi-brittle fracture mode. The shear fracture surface exhibited brittle fracture with regular arrangements of furrows. Internal fracture occurred along the spherical interface, as revealed by advanced in-situ X-ray microcomputed tomography. The experimental results agreed well with the theoretical predictions, indicating that the high-strength interface contributes to the overall strength and toughness of the sphere-containing structure.展开更多
Low collateral damage weapons achieve controlled personnel injury through the coupling of shock waves and particle swarms,where the particle swarms arise from the high-explosive dispersion of compacted metal particle ...Low collateral damage weapons achieve controlled personnel injury through the coupling of shock waves and particle swarms,where the particle swarms arise from the high-explosive dispersion of compacted metal particle ring.To investigate the dynamic response of the human target under combined shock waves and particle swarms loading,a physical human surrogate torso model(HSTM)was developed,and the dynamic response test experiment was conducted under the combined loading.The effects of particle size on the loading parameters,the damage patterns of the ballistic plate and HSTM,and the dynamic response parameters of the HSTM with and without protection are mainly analyzed.Our findings revealed that particle swarms can effectively delay the shock wave attenuation,especially the best effect when the particle size was 0.28–0.45 mm.The ballistic plate mainly exhibited dense perforation of the outer fabric and impacted crater damage of ceramic plates,whereas the unprotected HSTM was mainly dominated by high-density and small-size ballistic cavity group damage.The peak values of the dynamic response parameters for the HSTM under combined loading were significantly larger than those under bare charge loading,with multiple peaks observed.Under unprotected conditions,the peak acceleration of skeletons and peak pressure of organs increased with the particle size.Under protected conditions,the particle size,the number of particles hit,and the fit of the ballistic plate to the HSTM together affected the dynamic response parameters of the HSTM.展开更多
Low collateral damage munitions incorporate tens of thousands of submillimeter heavy metal particles in the shell,replacing the conventional metal shell.These munitions achieve near-field damage capabilities comparabl...Low collateral damage munitions incorporate tens of thousands of submillimeter heavy metal particles in the shell,replacing the conventional metal shell.These munitions achieve near-field damage capabilities comparable to that of conventional munitions,while relying on the dispersion decay characteristics of the particles to control the range of damage.However,the submillimeter size of particles poses signif-icant challenger in analyzing explosion-driven scattering.In this study,X-ray test was used to capture the scattering and dispersion state of the particle groups driven by blast load.The scattering evolution was simulated using the discrete element method(DEM)coupled with the finite element method(FEM).The extended velocity field distribution was analyzed in terms of the two-phase flow forces governing particle decay,to reveal the velocity evolution during particle group scattering and qualitatively analyze its influencing factors.Ensuring the strength of the layer structure,results indicate that lower particle content in the structural shell promotes easier expansion and rupture,enhancing the scattering ability of the particle group.The initial particle velocity is determined by the explosive energy and the mass ratio of the composite shell to the explosive(M/C).Near-field explosion dynamics involve complex in-teractions among shock waves,blast products,and particles groups in a multiphase medium.In contrast,far-field behavior reflects particle decay driven by air resistance,which is related to the resistance characteristic time.This study presents a method for calculating particle group velocity evolution,of-fering valuable insights for the engineering design and effect assessment of low collateral damage munitions.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.12372351).
文摘In this study, to meet the development and application requirements for high-strength and hightoughness energetic structural materials, a representative volume element of a TA15 matrix embedded with a TaZrNb sphere was designed and fabricated via diffusion bonding. The mechanisms of the microstructural evolution of the TaZrNb/TA15 interface were investigated via SEM, EBSD, EDS, and XRD.Interface mechanical property tests and in-situ tensile tests were conducted on the sphere-containing structure, and an equivalent tensile-strength model was established for the structure. The results revealed that the TA15 titanium alloy and joint had high density and no pores or cracks. The thickness of the planar joint was approximately 50-60 μm. The average tensile and shear strengths were 767 MPa and 608 MPa, respectively. The thickness of the spherical joint was approximately 60 μm. The Zr and Nb elements in the joint diffused uniformly and formed strong bonds with Ti without forming intermetallic compounds. The interface exhibited submicron grain refinement and a concave-convex interlocking structure. The tensile fracture surface primarily exhibited intergranular fracture combined with some transgranular fracture, which constituted a quasi-brittle fracture mode. The shear fracture surface exhibited brittle fracture with regular arrangements of furrows. Internal fracture occurred along the spherical interface, as revealed by advanced in-situ X-ray microcomputed tomography. The experimental results agreed well with the theoretical predictions, indicating that the high-strength interface contributes to the overall strength and toughness of the sphere-containing structure.
文摘Low collateral damage weapons achieve controlled personnel injury through the coupling of shock waves and particle swarms,where the particle swarms arise from the high-explosive dispersion of compacted metal particle ring.To investigate the dynamic response of the human target under combined shock waves and particle swarms loading,a physical human surrogate torso model(HSTM)was developed,and the dynamic response test experiment was conducted under the combined loading.The effects of particle size on the loading parameters,the damage patterns of the ballistic plate and HSTM,and the dynamic response parameters of the HSTM with and without protection are mainly analyzed.Our findings revealed that particle swarms can effectively delay the shock wave attenuation,especially the best effect when the particle size was 0.28–0.45 mm.The ballistic plate mainly exhibited dense perforation of the outer fabric and impacted crater damage of ceramic plates,whereas the unprotected HSTM was mainly dominated by high-density and small-size ballistic cavity group damage.The peak values of the dynamic response parameters for the HSTM under combined loading were significantly larger than those under bare charge loading,with multiple peaks observed.Under unprotected conditions,the peak acceleration of skeletons and peak pressure of organs increased with the particle size.Under protected conditions,the particle size,the number of particles hit,and the fit of the ballistic plate to the HSTM together affected the dynamic response parameters of the HSTM.
文摘Low collateral damage munitions incorporate tens of thousands of submillimeter heavy metal particles in the shell,replacing the conventional metal shell.These munitions achieve near-field damage capabilities comparable to that of conventional munitions,while relying on the dispersion decay characteristics of the particles to control the range of damage.However,the submillimeter size of particles poses signif-icant challenger in analyzing explosion-driven scattering.In this study,X-ray test was used to capture the scattering and dispersion state of the particle groups driven by blast load.The scattering evolution was simulated using the discrete element method(DEM)coupled with the finite element method(FEM).The extended velocity field distribution was analyzed in terms of the two-phase flow forces governing particle decay,to reveal the velocity evolution during particle group scattering and qualitatively analyze its influencing factors.Ensuring the strength of the layer structure,results indicate that lower particle content in the structural shell promotes easier expansion and rupture,enhancing the scattering ability of the particle group.The initial particle velocity is determined by the explosive energy and the mass ratio of the composite shell to the explosive(M/C).Near-field explosion dynamics involve complex in-teractions among shock waves,blast products,and particles groups in a multiphase medium.In contrast,far-field behavior reflects particle decay driven by air resistance,which is related to the resistance characteristic time.This study presents a method for calculating particle group velocity evolution,of-fering valuable insights for the engineering design and effect assessment of low collateral damage munitions.
