Nature-Inspired Gradient Material Structure with Exceptional Properties for Automotive Parts.

Inspired by natural gradient structures observed in biological systems such as lobster exoskeletons and bamboo, this study proposes a biomimetic strategy for developing advanced automotive materials that achieve an optimal balance between strength and ductility. Against this backdrop, the present work systematically reviews the design principles underlying natural gradient structures and examines the advantages and limitations of current additive manufacturing-specifically selective laser melting (AM-SLM)-as well as conventional forming and machining processes, in fabricating nature-inspired architectures. The research systematically explores hierarchical gradient designs which endow materials with superior mechanical properties, including enhanced strength, stiffness, and energy absorption capabilities. Two primary strengthening mechanisms-hetero-deformation-induced (HDI) hardening and precipitation hardening-were employed to overcome the conventional strength-ductility trade-off. Gradient-structured materials were fabricated using selective laser melting, and microstructural analyses demonstrated that controlled interface zones and tailored precipitation distribution critically influence property improvements. Based on these findings, an integrated material design strategy combining nature-inspired gradient architectures with post-processing treatments is presented, providing a versatile methodology to meet the specific performance requirements of automotive components. Overall, this work offers new insights for developing next-generation lightweight structural materials with exceptional ductility and damage tolerance and establishes a framework for translating bioinspired concepts into practical engineering solutions.