The key component of the explosive-formed projectile warhead is the parabolic or sphere-shaped charge cover with a cone Angle greater than 120°. When the explosive is detonated, the mouth of the charge cover turns back and deforms with a strain rate greater than 104/s to form the projectile, hit the armor and destroy the target. At present, red copper as a traditional EFP warhead cover material can not adapt to the development of armor protection technology, forcing the warhead research must seek a new cover material. The ideal EFP charge cover should meet the following requirements: high dynamic ductility, high density and fine grain structure to form a complete projectile. The increase of density means that the penetration ability can be improved with higher energy density and greater impact force. Enhanced ductility helps to form longer projectiles, thus increasing penetration depth.
Due to its high density (16.6g /cm3), good formability and high toughness, tantalum material is the first choice of explosive formed projectile cover abroad. Comparative tests show that under the same mass, the same aspect ratio and 2 km/s velocity, the penetration depth of the projectile formed by the tantalum cover into the homogeneous armor plate (hardness Hv320, yield strength 1050 MPa) is 160 mm, while the penetration depth of the projectile formed by the traditional copper cover is 123 mm. The explosively formed projectile formed by the tantalum drug cover is about 30% higher than that of the traditional copper cover. At present, tantalum material drug cover has been equipped with troops in foreign countries, and tantalum is widely used as the material of drug cover. Compared with foreign countries, the domestic drug cover mainly uses red copper as raw material. At present, in order to further improve the weapon power, tantalum or tantalum alloy drug cover has been used to replace red copper. However, the technical reserve of tantalum material drug cover in China is insufficient, which has seriously restricted the power improvement and application of the warhead.
Tantalum-tungsten alloy is the most widely studied tantalum cover material abroad. By adding tungsten element to pure tantalum, a single phase alloy with complete solution can be formed, which can increase the density and maintain good dynamic ductility. The results show that in order to ensure that the drug cover can withstand the deformation of high strain rate and large strain variable in the process of flipping, and finally form an effective projectile, it is required that the drug cover material has mechanical properties with good matching strength and plasticity, as well as fine crystalline and homogeneous microstructure. So this article in view of the tantalum tungsten alloy type medicine research on the heat treatment process, including medicine cover after forging forming bar and forging forming of medicine cover type, cover type by vacuum heat treatment medicine on the forging process of fibrous realize static recrystallization grains, and weaken the grain orientation, thus ensuring drug type cover has a larger penetration performance stability and good in deep.
