Bioinspired Wear-Resistant and Ultra-Durable Functional Gradient Coatings
Zhengzhi Wang, Kun Wang, Houbing Huang, Xiao Cui, Zuoqi Zhang, Martin Chiang
For mechanically protective coatings, the coating material usually requires sufficient stiffness and strength to resist external forces and meanwhile matched mechanical properties with the underneath substrate to maintain the structural integrity. These requirements generate a conflict that limits the coatings from achieving simultaneous surface properties (e.g. high wear-resistance) and coating/substrate interfacial durability. Here we resolve this conflict by developing a new concept and manufacturing technique for functional gradient coatings (FGCs) with the material composition and mechanical properties gradually varying crossing the coating thickness. The FGC is realized by controlling the spatial distribution of magnetic-responsive nanoreinforcements inside a polymer matrix through a magnetic actuation process. By concentrating the reinforcements with hybrid sizes at the surface region and continuously diminishing towards the coating/substrate interface, we demonstrate that the FGC exhibits simultaneously high surface hardness, stiffness, and wear-resistance, as well as superb interfacial durability that outperforms the homogeneous counterparts over an order of magnitude. This concept of FGC represents a mechanically-optimized strategy in achieving maximal performances with minimal use and site- specific distribution of the reinforcements, in accordance with the design principles of many load-bearing biological materials. The presented manufacturing technique for gradient nanocomposites can be extended to develop various bioinspired heterogeneous materials with unprecedented combination of mechanical properties.
, Wang, K.
, Huang, H.
, Cui, X.
, Zhang, Z.
and Chiang, M.
Bioinspired Wear-Resistant and Ultra-Durable Functional Gradient Coatings, Small, [online], https://doi.org/10.1002/smll.201802717
(Accessed August 7, 2022)