Abstract Designing and manufacturing high strength, low weight parts with enhanced impact resistance is highly sought after in the transportation industry. The most common methods to improve strength-to-weight ratios of impact targets is a composite material composition or a favorable geometric design. An alternative method to improve impact performance is functionally gradient mechanical properties in a single material by hybrid additive stacking. In this study, low velocity impact tests were conducted on hybrid stacked 1070 steel plates where individual layers were subjected to shot peening (SP) to functionally grade mechanical properties. Hybrid additive stacking refers to secondarily processing preferential layers within a stacked build volume by cold working to achieve favorable compressive residual stresses and localized work hardening. Incorporating SP on preferential layer intervals during stacking is a radically different approach to increase the strength-to-weight ratio and impact performance of metals. Cold working individual layers by peening achieves functionally gradient mechanical properties in a single material without the need for multi-material composite manufacturing. The objective of this work was to investigate the impact strength and energy absorption from stacking shot peened and non-shot peened layers to form a hybrid target. Identifying favorable stacking sequences provides insight on how to design a hybrid structure that incorporates a mechanical surface treatment (e.g., shot peening) to outperform conventional and composite targets. Results showed energy absorption improved by incorporating stacked shot peened layers and was dependent on the sequence. The improvement in impact performance was attributed to the shot peening induced compressive residual stresses and increased friction incorporated within predefined layers.

中文翻译：

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混合叠层钢板的低速冲击

摘要 设计和制造具有增强抗冲击性的高强度、低重量部件在运输行业中备受追捧。提高冲击目标的强度重量比的最常见方法是复合材料成分或有利的几何设计。提高冲击性能的另一种方法是通过混合添加剂堆叠在单一材料中实现功能梯度机械性能。在这项研究中，对混合堆叠的 1070 钢板进行了低速冲击试验，其中各个层都经过喷丸处理 (SP) 以达到功能分级的机械性能。混合添加剂堆叠是指通过冷加工对堆叠构建体积内的优先层进行二次加工，以实现有利的压缩残余应力和局部加工硬化。在堆叠期间在优先层间隔上加入 SP 是一种完全不同的方法，可以提高金属的强度重量比和冲击性能。通过喷丸冷加工单个层可在单一材料中实现功能梯度机械性能，而无需多材料复合制造。这项工作的目的是研究将喷丸和非喷丸层堆叠形成混合靶的冲击强度和能量吸收。确定有利的堆叠顺序有助于深入了解如何设计一种混合结构，该结构结合了机械表面处理（例如喷丸处理）以优于传统和复合目标。结果表明，通过结合堆叠喷丸强化层改善了能量吸收，并且取决于顺序。