Amorphous–Nanocrystalline Silicate–Superalloy Heterointerfaces Combining High‐Temperature Electrical Insulation with Large‐Strain Tolerance

The key bottleneck in in situ monitoring of nickel‐based superalloy hot‐section components is the lack of a reliable insulating interface for oxidative and thermomechanical extremes. Conventional ceramic insulating layers and multilayer architectures remain constrained by complex processing, interfacial mismatch, limited strain tolerance, and brittle failure. Here, we report a directly printable amorphous–nanocrystalline silicate coating that enables a robust multifunctional interface on nickel‐based superalloys without additional bonding or transition layers. During annealing, the printed silicate layer densifies, locally crystallizes, and wets the superalloy surface, producing an amorphous–nanocrystalline coating with a mechanically interlocked interface. The amorphous matrix ensures electrical insulation and oxygen‐barrier performance, while dispersed nanocrystals promote strain redistribution and crack‐path deflection. The integrated structure allows the coating to maintain stable insulation at 1100°C, achieve an adhesion strength of 90.5 N, substantially suppress high‐temperature oxidation, and remain structurally intact under strains exceeding 18,000 µε. Integrated Pt thin‐film strain sensors achieve stable strain monitoring at 1100°C, and turbine‐blade demonstration further validates the printable insulating interface for conformal integration and accurate high‐temperature sensing. The printable single‐coating strategy provides a multilayer‐free interfacial platform for robust high‐temperature sensing on superalloy components.