从局域应力/应变视角理解异构金属材料的强韧化行为

Unraveling the Strength-Ductility Synergy of Heterostructured Metallic Materials from the Perspective of Local Stress/Strain

同步提升强度与塑性是金属材料研究的不懈追求之一。近年来,异构设计通过调控力学性质存在显著差异的组元相的空间分布,突破了金属材料强度与塑性难兼得的瓶颈。异构变形诱导强化、应变分配、延迟颈缩、界面影响区等主流理论为异构金属材料设计提供了有力指导,上述理论均指出,在受载过程中,异构金属材料组元相的局域应力与局域应变存在独特特征,并伴随偏离经典理论预测的变形和断裂行为。本文综述了异构金属材料在早期变形阶段、塑性变形阶段和断裂阶段中局域应力和局域应变演化,归纳了异构金属材料中变形行为、断裂行为与局域应力、局域应变的交互关系及对力学性能的影响,为高性能异构金属材料的设计和研发提供新的思路。

The concurrent enhancement of strength and ductility is an unremitting pursuit in metallic material research.Recently,by deliberately controlling the spatial distribution of domains with substantially different mechanical properties,heterostructured architecture has overcome the limitation of strengthductility synergy in metallic materials.Mainstream theories,such as hetero-deformation-induced hardening,strain partition,premature local necking delay,and interface affected zone,have provided crucial guidance for the designing of preferable heterostructured metallic materials.These theories suggest that the domains of heterostructured metallic materials present unique local stress and strain characteristics upon loading,accompanying deformation and fracture behaviors that deviate from the predictions of classical theories.In this study,the evolutions of local stress and strain during the early deformation,plastic deformation,and fracture stages of heterostructured metallic materials were reviewed.Moreover,interactions between deformation or fracture behaviors and local stress or strain as well as their effects on mechanical properties are summarized,presenting a new perspective for designing and developing highperformance heterostructured metallic materials.