Research On Explosive Compaction Of W-cu Nanoalloy And The Application To Shaped Charge Liner

Explosive compaction utilizes shock wave generated by detonation of explosive to densify powders. The wave pressure imposes plastic deformation on the container, which results in ultra-rapid consolidation of the powders. The high pressure is exerted for a very short duration, in the order of a microsecond, resulting in densification at extremely high strain rates. Due to the rapid process, the boundries of the composite particles would hardly diffuse or a little. It could overcome the segregation of alloy element and prevent the recrystallization and grain growth by minimizing the starting powders'exposure to high temperature.Generally, Cu infiltration of W preforms or liquid phase sintering of W-Cu powder mixture has been used to fabricate densified W-Cu composites. But it is difficult to fabricate alloy and composites with a homogeneous microstructure, because W and Cu have no solubility of each other through the whole composition. With the progress in mechanical alloying of powder mixtures of W-Cu, however, it is now possible to obtain composites with homogeneous and nanocrystalline microstructure. In the paper, the nanocrystalline W-Cu alloy powders are explosively compacted. The W-Cu nanoalloy is applied to shaped charge liner and the effects of quiet armor piercing experiment is excellent. These mentioned questions are investigated by experiment and theory.In the study, the nanocrystalline W-Cu alloy powders are produced by mechanical alloying and mechanochemical process, respectively. And the W-Cu alloy powders are analyzed. The results shows that the alloy powders could be fully reduced at850℃in conditions of W-Cu and W-CuO mixtures. To demonstrate the W crystalline, the mixtures were mixed into concentrated sulphuric acid. Cu dissolves in concentrated sulphuric acid under the condition of heating, and the W crystalline size of the reduced powders were showed as about30nm. But the oxide of W could not be fully reduced in conditions of WO3-Cu. The Cu powder would be sintered before arriving at the reduced temperature of WO3, consequently this would prevent the couse of deoxidization due to the sintered Cu. The oxide would be exposed after the explosive compaction. Explosive powder compaction was employed for the fabrication of W-Cu nanoalloys. The effect of detonation velocity of explosive on density has been studied. The compacted specimens had the biggest density when the detonation velocity was5300m/s. The specimen could be compacted to more than99%theoretical density. The composition and distribution of the elements were determined by EPMA, and the results showed that the distribution of these compositions was uniform. The fracture surface was analyzed by SEM and showed intergranular fracture. The hardness was measured.The theoretical calculation of the process of explosive compaction is made. The detonation parameters of the explosive are calculated. By the approximate compositions of detonation product, the adiabatic exponent are obtained. Based on the k equation of detonation product, the parameters of JWL equation of state are fitted. The physical parameters of the W-Cu powder mixtures are computed. Finally the p-ν relationship in the shock adiabatic condition is obtained by constructing p-α shock equation of state. The isentropic uploding process of the powder is analyzed.The process of powder compaction is numerically simulated using LS-DYNA program. After the detonation wave come into the powder, the propagation course of shock wave is studied. The distortion rule of the powders is analyzed.The W-Cu alloy is applied to the manufacturing of liner. The W-Cu powder is compacted twice, respectively under low and high explosion velocity. The sample was machined into W-Cu alloy liners, showing good forming property. Quiet armor piercing experiment of the W-Cu alloy liner of shaped charge without an insulating board indicates that the armor piercing capability is increased by more than30percent in comparison with the copper liner. The effect of quiet armor piercing experiment of shaped charge is analyzed by theory and numerical simulation.