As one of the three major engineering materials, metals are widely used in aerospace, biomedical, and other fields. However, they generally suffer from issues such as mutual constraints between stiffness and damping, low specific modulus and specific hardness, and susceptibility to corrosion. Traditional composite methods or high-entropy strategies often sacrifice other properties when enhancing one specific performance.
Inspired by the excellent mechanical properties and structural stability of natural tooth enamel, we innovatively propose a universal strengthening strategy for in-situ constructing enamel-like ceramic layers on metal surfaces, achieving simultaneous improvements in metal stiffness, damping, and corrosion resistance. This strategy combines liquid-phase oxidation synthesis with controlled hydrolysis processes to in-situ construct enamel-like ceramic layers composed of regular crystalline nanoarrays and amorphous matrix on the surfaces of four common functional metals: zirconium, titanium, zinc, and copper. This structure ingeniously combines the strong supporting effect of the crystal arrays with the efficient energy dissipation mechanism of the crystal-amorphous interface, enabling the strengthened metals to simultaneously achieve high stiffness, high damping, and excellent specific modulus and specific hardness. Specifically, the viscoelastic quality factor of strengthened zirconium metal reaches 4.6 GPa, which is the highest value among metals at room temperature; the specific modulus of strengthened titanium metal reaches 30.9 GPa/(g/cm³), comparable to lightweight metals such as magnesium and aluminum, and it also exhibits good biocompatibility. Meanwhile, the dense enamel-like ceramic layer and the internal amorphous component can significantly inhibit the invasion of corrosive substances, endowing the metal with excellent corrosion resistance.
This work successfully breaks through the technical bottleneck that metal stiffness and damping are difficult to achieve simultaneously and prone to corrosion, providing a new bionic design idea for developing high-performance and long-lasting metals.
Shaojia Liu, Jingjing Deng, Hewei Zhao, Tianbai Wang, Junfeng Lu, Baosen Ding, Tianqi Guo, Robert O. Ritchie and Lin Guo. Tooth enamel-inspired ceramic coating on metal surface for enhanced mechanical properties and corrosion resistance. Nat. Commun., 2025, 16: 5980.
https://www.nature.com/articles/s41467-025-61060-1
