冲击加载条件下金属粉末的动态力学性能分析
Analysis on dynamic mechanics performance of metal powders by impact loading
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摘要: 为研究金属粉末在冲击加载过程中, 粉末预压力对压坯动态力学响应的影响, 设计了基于分离式霍普金森压杆装置(split Hopkinson pressure bar, SHPB)的金属粉末高应变率冲击加载实验, 并结合一维应力波理论对预压后粉末压坯的力学性能进行分析。结果表明:在冲击过程中, 金属压坯会表现出较为明显的应变率效应; 加载率越大, 材料的应变能越大, 预压力越大, 应变硬化率越大; 在相同的加载条件下, 预压力越大, 压坯临界位移越小。Abstract: A split Hopkinson pressure bar (SHPB) test system was designed to study the dynamic mechanics performance of metal particle by impact loading. The powder mechanical properties were analyzed by one-dimensional stress wave theory. The results show an obviously strain rate effect in the impact compaction process. As the pre-pressure increases, the faster loading rate results in the larger material strain energy, and the strain hardening rate is higher. The critical displacement of green-compacts is decreased with the increase of pre-pressure under the same loading condition.