Enhancing wide-temperature-range wear resistance of the h-BN/Si₃N₄self-lubricating composite via constructing 3D continuous structure

To address severe adhesive wear caused by Si₃N₄oxidation under extreme tribological conditions (1200 °C), an architectured ceramic composite was engineered with dual-phase integration: a continuous Si₃N₄framework embedding spherical h-BN domains. This structural hierarchy effectively mitigates oxide adhesion through spatially modulated hardness gradients, contrasting with conventional homogeneous solid-lubricant dispersion methods. The 3D composite's micron-scale soft/hard alternating configuration yields synergistic tribological enhancement, demonstrating 32.5 % coefficient of friction decrease and 88 % wear rate improvement compared to the isotropic composite. Mechanistic investigations reveal threefold performance determinants: (1) The Si₃N₄skeleton provides exceptional load-bearing capacity, (2) h-BN domains facilitate low shear stress interfacial sliding, (3) self-organized tribolayer formation occurs through dynamic interaction of amorphous oxides, Si₃N₄nanocrystals (<100 nm), and exfoliated h-BN nanosheets during sliding. This multi-scale architecture enables simultaneous realization of surface energy minimization and subsurface damage suppression.