Electric fields induced by ring and pin electrodes in electrostatic charged powder sprayingtechnique are analysed. The fundamental formulae to deseribe these fields have been built up. Theseformulae could be used to d...Electric fields induced by ring and pin electrodes in electrostatic charged powder sprayingtechnique are analysed. The fundamental formulae to deseribe these fields have been built up. Theseformulae could be used to design electrostatic charged podwer spraying system. The chargingeffectiveness of ring and pin electrode is experimentally investigated and compared each other. Theperformance of ring electrode is better than that of pin electrode.展开更多
Aluminum（Al） powders are used in composite explosives as a typical reducing agent for improving explosion performance. To understand energy release of aluminum in aluminized RDX-based explosives, a series of thermal...Aluminum（Al） powders are used in composite explosives as a typical reducing agent for improving explosion performance. To understand energy release of aluminum in aluminized RDX-based explosives, a series of thermal measurements and underwater explosion（UNDEX） experiments were conducted. Lithium fluoride（LiF） was added in RDX-based explosives, as a replacement of aluminum, and used in constant temperature calorimeter experiments and UNDEXs. The influence of aluminum powder on explosion heat（Qv） was measured. A rich supply of data about aluminum energy release rate was gained. There are other oxides（CO2, CO, and H2O） in detonation products besides alumina when the content of RDX is maintained at the same levels. Aluminum cannot fully combine with oxygen in the detonation products. To study the relationship between the explosive formulation and energy release, pressure and impulse signals in underwater experiments were recorded and analyzed after charges were initiated underwater. The shock wave energy（Esk）, bubble energy（Eb）, and total energy（Et） monotony increase with the Al/O ratio, while the growth rates of the shock wave energy,bubble energy, and total energy become slow.展开更多
In order to study the properties of sintered copper powder shaped charge liner, the copper powder, whose particle size was below 20 μm, was chosen as the main material. The mixed powders were directly pressed into th...In order to study the properties of sintered copper powder shaped charge liner, the copper powder, whose particle size was below 20 μm, was chosen as the main material. The mixed powders were directly pressed into the desired shape of the shaped charge liner by the top direct-pressure way. The microscopic morphology of the spinning shaped charge liner, the sintered and non-sintered powder liners, and the particle properties of the copper powder were studied with scanning electron microscopy. The expe^mental results showed that the irregular copper powder could get together effectively and sintering could improve the compactness of the powder liner effectively. The wall thickness and density of the non-sintered and sintered liner were also tested, and it shows that sintering causes the wall thickness thinned and the density improved. The penetration depths of non-sintered powder liner, sintered powder liner and the spinning copper plate liner were tested with different standoff respectively, showing that the penetration properties of sintered powder liner are well.展开更多
Rapid prototype manufacturing(RPM) is a new advanced manufacturing technology, which is based on the philosophy of materials increasing of lay by lay forming. Zero adventure rapid design/manufacturing can be realized ...Rapid prototype manufacturing(RPM) is a new advanced manufacturing technology, which is based on the philosophy of materials increasing of lay by lay forming. Zero adventure rapid design/manufacturing can be realized with rapid prototypes of 3D CAD of products. Rapid prototyping has been an effective tool of R&D of new products. A novel rapid prototyping and manufacturing (RP&M) technique is brought forward. The principle of the process is to form layered sections and to make the prototype or part layer by layer by deflection projection of electric charged powder granules passing through electric or magnetic field and by controllable line and field scan of the powder granule beam. The feasibility issue of the process is theoretically and experimentally investigated.It shows that deflection projection of electric charged powder granules beam passing through electric field can be significant and feasible to the rapid prototyping technique.展开更多
文摘Electric fields induced by ring and pin electrodes in electrostatic charged powder sprayingtechnique are analysed. The fundamental formulae to deseribe these fields have been built up. Theseformulae could be used to design electrostatic charged podwer spraying system. The chargingeffectiveness of ring and pin electrode is experimentally investigated and compared each other. Theperformance of ring electrode is better than that of pin electrode.
文摘Aluminum（Al） powders are used in composite explosives as a typical reducing agent for improving explosion performance. To understand energy release of aluminum in aluminized RDX-based explosives, a series of thermal measurements and underwater explosion（UNDEX） experiments were conducted. Lithium fluoride（LiF） was added in RDX-based explosives, as a replacement of aluminum, and used in constant temperature calorimeter experiments and UNDEXs. The influence of aluminum powder on explosion heat（Qv） was measured. A rich supply of data about aluminum energy release rate was gained. There are other oxides（CO2, CO, and H2O） in detonation products besides alumina when the content of RDX is maintained at the same levels. Aluminum cannot fully combine with oxygen in the detonation products. To study the relationship between the explosive formulation and energy release, pressure and impulse signals in underwater experiments were recorded and analyzed after charges were initiated underwater. The shock wave energy（Esk）, bubble energy（Eb）, and total energy（Et） monotony increase with the Al/O ratio, while the growth rates of the shock wave energy,bubble energy, and total energy become slow.
基金Funded by the National Natural Science Foundation of China(No.11072222)
文摘In order to study the properties of sintered copper powder shaped charge liner, the copper powder, whose particle size was below 20 μm, was chosen as the main material. The mixed powders were directly pressed into the desired shape of the shaped charge liner by the top direct-pressure way. The microscopic morphology of the spinning shaped charge liner, the sintered and non-sintered powder liners, and the particle properties of the copper powder were studied with scanning electron microscopy. The expe^mental results showed that the irregular copper powder could get together effectively and sintering could improve the compactness of the powder liner effectively. The wall thickness and density of the non-sintered and sintered liner were also tested, and it shows that sintering causes the wall thickness thinned and the density improved. The penetration depths of non-sintered powder liner, sintered powder liner and the spinning copper plate liner were tested with different standoff respectively, showing that the penetration properties of sintered powder liner are well.
文摘Rapid prototype manufacturing(RPM) is a new advanced manufacturing technology, which is based on the philosophy of materials increasing of lay by lay forming. Zero adventure rapid design/manufacturing can be realized with rapid prototypes of 3D CAD of products. Rapid prototyping has been an effective tool of R&D of new products. A novel rapid prototyping and manufacturing (RP&M) technique is brought forward. The principle of the process is to form layered sections and to make the prototype or part layer by layer by deflection projection of electric charged powder granules passing through electric or magnetic field and by controllable line and field scan of the powder granule beam. The feasibility issue of the process is theoretically and experimentally investigated.It shows that deflection projection of electric charged powder granules beam passing through electric field can be significant and feasible to the rapid prototyping technique.
