Heterostructured laminates have attracted significant attention in the materials community owing to their exceptional combination of strength and ductility. However, long-standing questions remain regarding the impact of the strength difference between the soft and hard layers on the synergistic strengthening in hetero-laminates with weak mechanical heterogeneity; the role played by soft/hard layers with various dislocation storage capacities on the strength–ductility synergy is also poorly understood. In this study, a series of typical heterostructured copper–brass laminates were fabricated using the diffusion welding + forging + rolling + annealing technique. The results demonstrated that larger microstructural and mechanical heterogeneities improved the strength–ductility combination of the hetero-laminates. The relatively weak mechanical heterogeneity and superior dislocation storage capacity of the soft copper and hard brass layers facilitated inter-layer synergistic deformation. This induced a gradual distribution of local strains and geometrically necessary dislocations (GNDs) near the hetero-interface. Thus, when evaluating the role of soft layers in synergistic strengthening, it is crucial to consider their generation and storage capabilities for dislocations.

中文翻译：

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机械异质性和位错存储能力对异质结构层合板强度-延展性协同的影响

异质结构层压板由于其强度和延展性的出色结合而引起了材料界的广泛关注。然而，软硬层之间的强度差异对机械异质性较弱的异质层压板协同强化的影响仍然存在长期的问题；具有各种位错存储能力的软/硬层对强度-延展性协同作用所起的作用也知之甚少。在本研究中，采用扩散焊+锻造+轧制+退火技术制造了一系列典型的异质结构铜-黄铜层压板。结果表明，较大的微观结构和机械异质性改善了异质层压板的强度-延展性组合。软铜和硬黄铜层相对较弱的机械异质性和优异的位错存储能力有利于层间协同变形。这导致异质界面附近局部应变和几何必要位错 (GND) 逐渐分布。因此，在评估软层在协同强化中的作用时，考虑它们的位错产生和存储能力至关重要。