WFeNiMo高熵合金动态力学行为及侵彻性能研究

为了探究不同应变速率下WFeNiMo高熵合金的变形行为和侵彻性能, 采用万能材料试验机、分离式霍普金森压杆开展了高熵合金的静动态力学性能试验, 讨论了其在不同应变速率下变形特征微观机制. 基于弹道枪试验平台开展了高熵合金与典型钨合金(93W-4.9Ni-2.1Fe,wt%)破片对有限厚钢靶侵彻作用性能试验研究, 分析了两种合金破片侵彻作用过程与靶板破坏特征、侵彻穿孔能量消耗与撞击速度间的关系. 结果表明: 高熵合金、钨合金材料屈服强度与应变率呈正相关, 且在相同的应变率下高熵合金具有更高的屈服强度; 随着应变率的提高, 高熵合金由脆性断裂、韧脆混合的准解理断裂发展至具有黏着特性的破碎变形模式; 高熵合金具有较强的局部绝热变形能力, 在侵彻薄钢靶时体现出较高的剪切敏感性; 相同撞击速度下, 高熵合金破片穿靶消耗的能量低于钨合金破片, 对于薄钢靶具有更强的侵彻穿透能力. 高熵合金具有优异的力学性能和侵彻能力, 在高速撞击薄靶板时除了传统的剪切冲塞作用还具有一定的能量释放特性, 在预制破片上有较好的应用前景. 

DYNAMIC MECHANICAL BEHAVIOR AND PENETRATION PERFORMANCE OF WFeNiMo HIGH-ENTROPY ALLOY

In order to investigate the deformation behavior and penetration performance of WFeNiMo high-entropy alloy under different strain rates, the static mechanical properties of the high-entropy alloy was tested by universal material testing machine and the dynamic mechanical properties of the high-entropy alloy was tested by the SHPB (split Hopkinson pressure bar). The micro mechanism of deformation characteristics of the alloy under different strain rates was also discussed. Based on the ballistic gun test platform, the fragments penetration performance of the high-entropy alloy and the typical tungsten alloy (93W-4.9Ni-2.1Fe, wt%) to the finite thickness steel target was studied. The relationship between the penetration process of the two kinds of alloy fragments and the target damage characteristics, the energy consumption of penetration and the impact velocity was analyzed. The results show that the yield strength and strain rate of the high-entropy alloy and tungsten alloy present a positively correlation. The yield strength of the high-entropy alloy is higher than the tungsten alloy under the same strain rate. With the increase of strain rate of deformation, the high-entropy alloy develops from the brittle fracture, quasi-cleavage with the mixing of tough and brittle characters to the fracture deformation mode with adhesive characteristics. The high-entropy alloy has a strong local adiabatic deformation ability and high shear sensitivity when the fragments penetrate into the thin steel targets. The energy consumption of the high-entropy alloy fragments penetrating into the target is lower than the tungsten alloy fragments under the same impact velocity. The high--entropy alloy has excellent mechanical properties and superior performance in the penetration ability. In addition to the traditional shear plug effect, there is a certain energy release characteristic when the thin target is impacted at high speed by the high-entropy alloy fragments and it has a good application prospect in the field of the preformed fragments.