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Composite bending-dominated hollow nanolattices: A stiff, cyclable mechanical metamaterial
Materials Today ( IF 24.2 ) Pub Date : 2018-06-01 , DOI: 10.1016/j.mattod.2018.03.027
Biwei Deng , Rong Xu , Kejie Zhao , Yongfeng Lu , Sabyasachi Ganguli , Gary J. Cheng

Abstract Manufacturing ultralight and mechanical reliable materials has been a long-time challenge. Ceramic-based mechanical metamaterials provide significant opportunities to reverse their brittle nature and unstable mechanical properties and have great potential as strong, ultralight, and ultrastiff materials. However, the failure of ceramics nanolattice and degradation of strength/modulus with decreasing density are caused by buckling of the struts and failure of the nodes within the nanolattices, especially during cyclic loading. Here, we explore a new class of 3D ceramic-based metamaterials with a high strength–density ratio, stiffness, recoverability, cyclability, and optimal scaling factor. Deformation mode of the fabricated nanolattices has been engineered through the unique material design and architecture tailoring. Bending-dominated hollow nanolattice (B-H-Lattice) structure is employed to take advantages of its flexibility, while a few nanometers of carbonized mussel-inspired bio-polymer (C-PDA) is coherently deposited on ceramics’ nanolayer to enable non-buckling struts and bendable nodes during deformation, resulting in reliable mechanical properties and outperforming the current bending-dominated lattices (B-Lattices) and carbon-based cellulose materials. Meanwhile, the structure has comparable stiffness to stretching-dominated lattices (S-Lattices) while with better cyclability and reliability. The B-H-Lattices exhibit high specific stiffness (>10 6 Pa·kg −1 ·m −3 ), low-density (∼30 kg/m 3 ), buckling-free recovery at 55% strain, and stable cyclic loading behavior under up to 15% strain. As one of the B-Lattices, the modulus scaling factor reaches 1.27, which is lowest among current B-Lattices. This study suggests that non-buckling behavior and reliable nodes are the key factors that contribute to the outstanding mechanical performance of nanolattice materials. A new concept of engineering the internal deformation behavior of mechanical metamaterial is provided to optimize their mechanical properties in real service conditions.

中文翻译:

复合弯曲主导的空心纳米晶格:一种坚硬、可循环的机械超材料

摘要 制造超轻且机械可靠的材料一直是一项长期挑战。陶瓷基机械超材料为扭转其脆性和不稳定的机械性能提供了重要的机会,并具有作为强、超轻和超硬材料的巨大潜力。然而,陶瓷纳米晶格的失效和强度/模量随密度降低的降低是由支柱的屈曲和纳米晶格内的节点失效引起的,尤其是在循环加载期间。在这里,我们探索了一类具有高强度密度比、刚度、可恢复性、可循环性和最佳缩放因子的新型 3D 陶瓷基超材料。制造的纳米晶格的变形模式是通过独特的材料设计和架构剪裁设计的。采用弯曲主导的中空纳米晶格(BH-Lattice)结构以利用其灵活性,而几纳米的碳化贻贝生物聚合物(C-PDA)相干沉积在陶瓷纳米层上,以实现非屈曲支柱和变形过程中的可弯曲节点,从而产生可靠的机械性能并优于当前以弯曲为主的晶格(B-Lattices)和碳基纤维素材料。同时,该结构具有与拉伸主导晶格(S-Lattices)相当的刚度,同时具有更好的循环性和可靠性。BH-晶格表现出高比刚度(>10 6 Pa·kg -1 ·m -3 )、低密度(~30 kg/m 3 )、55% 应变下的无屈曲恢复和稳定的循环载荷行为高达 15% 的应变。作为 B 格之一,模量比例因子达到 1.27,是目前 B-Lattice 中最低的。这项研究表明,非屈曲行为和可靠的节点是促成纳米晶格材料优异机械性能的关键因素。提供了一种设计机械超材料内部变形行为的新概念,以优化其在实际使用条件下的机械性能。
更新日期:2018-06-01
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