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In order to study the explosive welding experimental fabrication technology of multi-layer dissimilar metal plates and the quality of bonding interface, three-layer steel/aluminum/steel composite plates with different thickness distributions were fabricated using the method of explosive welding when their total thicknesses remained same (total 5 mm). Then the stereomicroscope was adopted to investigate the shape of bonding interface and the formed mechanism was also analyzed. In addition, the micro-hardness (Vickers hardness, Hv) distribution of the composite plate in the thickness direction was studied by a low load Vickers hardness tester. The results show that the method of explosive welding can be used to fabricate three-layer steel/aluminum/steel dissimilar metal plates successfully. Meanwhile, wave bonding interface was formed between steel fly plate and aluminum middle plate, straight bonding interface was formed between aluminum middle plate and steel base plate. The maximum Hv value of welded plate appears at the bonding interface with high bonding strength. The bonding strength of both two kinds of welded interface was considered sufficient, which offers experimental support for the explosive welding of multi-layer plates.

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In order to study the penetration performance of the tandem warhead composed of a front circular shaped charge and a rear penetration projectile, a grooved steel plate was processed to simulate the effect of circular shaped jets on metal plate, then the failure mechanism of the grooved steel plate impacted by rear projectile was investigated by ballistic experiment, meanwhile, the effect of projectile nose shape on the failure mechanism was also analyzed. The results show that the main failure mechanism of grooved steel plate is ductile tensile deformation or damage when the projectile impacted on the inner plate body and the depth of the pre-splitting groove is not big enough (usually more than 4mm), on the other hand, the circumferential sheared fracture of the bottom of the groove occurred when the depth of the pre-splitting groove is not less than 4mm. The oval projectile body has much greater erosion damage than rod-shaped projectile during the penetration process.