Experimental and numerical investigation of lightweight high-entropy alloys shaped charge jet and its penetration performance

Lightweight high-entropy alloys (LHEAs) are a new type of alloy with excellent mechanical properties. It provides an effective technical solution to the problem that lightweight alloy shaped charge (SC) jets are difficult to balance in terms of perforation diameter and penetration depth. In this paper, CoCrFeNiTi_0.4 LHEA was evaluated by static and dynamic mechanical tests, and its constitutive model was fitted to establish a simulation model. Through the numerical simulation and experimental verification, the influence mechanism of liner thickness on the forming behavior and damage performance of LHEA jets was systematically studied, and their performance was compared with that of titanium jets. The mechanical test results indicate that CoCrFeNiTi_0.4 LHEA exhibits excellent plastic deformation ability, which is conducive to forming a jet with improved cohesion and enhanced penetration continuity when used as a liner. Based on the mechanical test results, the LHEA material model is fitted, and the numerical simulation model is established. Experiments verified the effectiveness of the simulation model. The findings of the study reveal that as the thickness of the liner increases, the jet tip velocity exhibits a declining trend, while the homogeneity of the jet is markedly enhanced. This pattern of variation results in a significant enlargement of the perforation diameter. Conversely, the penetration depth demonstrates a nonlinear characteristic, initially increasing before subsequently decreasing. Compared to conventional titanium jets, the LHEA jets exhibit significantly superior damage efficacy, with a perforation diameter increase of up to 50% in steel targets. Moreover, the optimized LHEA jets achieve a penetration depth over 12% greater than pre-optimized titanium jets while maintaining comparable perforation capabilities, demonstrating overall performance advantages.