Abstract In recent years, cellular metallic materials have attracted significant interest for biomedical applications. However, mutually opposing requirements of porous architecture and mechanical strength in conjunction with the high energy absorption capability have restricted their use. Here, we illustrate that electron beam melting can fabricate functionally graded Ti-6Al-4V alloy interconnected mesh structures with a combination of low density (0.5–2 g/cm3), high fatigue strength (∼70 MPa) and energy absorption (∼50 MJ/mg), which is superior to the ordinary uniform cellular structures. The underlying fundamental mechanisms governing the compressive and fatigue behavior of the graded cellular structures are elucidated via in situ tomography experiments and digital volume correlation analyses. It is underscored that during cyclic deformation, the stress can be continuously redistributed because of inhomogeneous mechanical properties and crack formation in constituent meshes, thereby resulting in variation of cyclic ratcheting rate for the graded cellular structures.

中文翻译：

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电子束熔化制备功能梯度 Ti-6Al-4V 网格的压缩和疲劳行为

摘要 近年来，细胞金属材料在生物医学应用方面引起了极大的兴趣。然而，多孔结构和机械强度以及高能量吸收能力的相互对立的要求限制了它们的使用。在这里，我们说明了电子束熔化可以制造具有低密度 (0.5-2 g/cm3)、高疲劳强度 (~70 MPa) 和能量吸收 (~50 MJ/mg)，优于普通的均匀细胞结构。通过原位断层扫描实验和数字体积相关分析阐明了控制分级细胞结构的压缩和疲劳行为的基本机制。需要强调的是，在循环变形过程中，