控制金属玻璃(MGs)中的局部异质性代表了提高其可塑性的新兴领域。防止造成宏观脆性破坏的灾难性剪切带(SB)的传播。迄今为止,一种旨在精细调节局部异质性控制SB成核和传播的纳米工程方法仍然缺失,阻碍了开发具有大且可调强度/延展性平衡和受控变形行为的MGs的潜力。在这项工作中,我们利用脉冲激光沉积(PLD)的潜力来合成一类新型的晶体/玻璃超细纳米层压板(U-NLs),其中4nm厚的晶体Al分离6和9nm厚的Zr50Cu50玻璃纳米层,同时报告了高密度的尖锐界面和大的化学混合。此外,我们通过合成致密和纳米颗粒的U-NL来调整形态,剥削,分别,逐个原子或簇组装的生长方式。对于紧凑型U-NL,我们报告了高质量密度(~8.35g/cm3)和增强和可调的机械性能,达到高达9.3和3.6GPa的硬度和屈服强度的最大值,分别。此外,由于富含Al的子层的SB阻塞,我们在压缩中显示出高达3.6%的均匀弹塑性变形。另一方面,纳米颗粒U-NLs表现出较低的屈服强度(3.4GPa)与增强的弹塑性变形(〜6%)相结合,然后形成表面SB,即使在变形超过15%时也不渗透,由于簇组装结构内较大的自由体积含量和晶体/玻璃纳米界面的存在,能够适应SB事件。总的来说,我们展示了PLD如何使晶体/玻璃U-NL的合成与局部异质性的最终控制下降到原子尺度,提供能够深度控制变形行为的新纳米工程策略,超越传统的强度和延展性之间的权衡。我们的方法可以扩展到金属材料的其他组合,对工业应用有明显的兴趣,例如结构涂层和微电子(MEMS和NEMS)。
The control of local heterogeneities in metallic glasses (MGs) represents an emerging field to improve their plasticity, preventing the propagation of catastrophic shear bands (SBs) responsible for the macroscopically brittle failure. To date, a nanoengineered approach aimed at finely tuning local heterogeneities controlling SB nucleation and propagation is still missing, hindering the potential to develop MGs with large and tunable strength/ductility balance and controlled deformation behavior. In this work, we exploited the potential of pulsed laser deposition (PLD) to synthesize a novel class of crystal/glass ultrafine nanolaminates (U-NLs) in which a ∼4 nm thick crystalline Al separates 6 and 9 nm thick Zr50Cu50 glass nanolayers, while reporting a high density of sharp interfaces and large chemical intermixing. In addition, we tune the morphology by synthesizing compact and nanogranular U-NLs, exploiting, respectively, atom-by-atom or cluster-assembled growth regimes. For compact U-NLs, we report high mass density (∼8.35 g/cm3) and enhanced and tunable mechanical behavior, reaching maximum values of hardness and yield strength of up to 9.3 and 3.6 GPa, respectively. In addition, we show up to 3.6% homogeneous elastoplastic deformation in compression as a result of SB blocking by the Al-rich sublayers. On the other hand, nanogranular U-NLs exhibit slightly lower yield strength (3.4 GPa) in combination with enhanced elastoplastic deformation (∼6%) followed by the formation of superficial SBs, which are not percolative even at deformations exceeding 15%, as a result of the larger free volume content within the cluster-assembled structure and the presence of crystal/glass nanointerfaces, enabling to accommodate SB events. Overall, we show how PLD enables the synthesis of crystal/glass U-NLs with ultimate control of local heterogeneities down to the atomic scale, providing new nanoengineered strategies capable of deep control of the deformation behavior, surpassing traditional trade-off between strength and ductility. Our approach can be extended to other combinations of metallic materials with clear interest for industrial applications such as structural coatings and microelectronics (MEMS and NEMS).