Enhancement of wear resistance via ZrB 2 /TiO 2 hard–soft structured coatings with engineered interfacial structures

Inspired by dung beetle shells, hard–soft structured coatings (HSSCs) with noncoherent interfaces were developed via plasma electrolytic oxidation to wear resistance. The ZrB2/TiO2 noncoherent interface with a 3:2 ratio generated abundant dislocations under low mismatch (45.6%), acting as ceramic coatings deformation carriers. This interface promoted regularized dislocation pile-ups distribution, reducing migration resistance. However, further interface number increases induced strain-field superposition and excessive dislocation pile-ups, causing structural instability. Comparing PEO, HSSCs hardness and elastic modulus enhanced by 56.0% and 50.1%, coefficient of friction and wear rate decreased by 61.7% and 71.9%. This work provides fundamental insights for hard–soft ceramic interface design.