This study aimed to reveal the impact wear behaviors of tempered 25Cr3Mo2NiWV steel. The specimens were subject to various heat treatment processes for generating different mechanical and wear properties. The impact wear tests were performed with an MLD-10 dynamic abrasive wear tester. Worn surface morphologies and micro-cracks of the cross-sections were analyzed by optical microscope and scanning electron microscope. The Vickers hardness of the sample and the impact wear mechanism were also analyzed. The steel with the best combination of hardness and toughness had the lowest wear. With the increase of wear time, the dominant wear mechanism varied from slight plastic deformation to micro-cutting and adhesive wear. Finally, micro fatigue peeling occurred. After impact wear, the cracks could initiate from the surface or the sub-surface. Micrographs of the crack in the cross-section demonstrated two different propagation modes of fatigue fractures. The results showed that the strength and toughness of steel affected the crack propagation, surface spalling, and wear failure mechanism during impact wear.

Continuous fiber-reinforced ceramic matrix composites (CFRCMCs) are extensively applied in high-temperature fields such as aerospace, energy, and transportation due to their superior mechanical and thermal properties. The explicit and numerical cross-property relations of CFRCMCs are established by integrating a generalized self-consistent scheme, effective-medium conduction models, and finite element analysis. The results reveal that CFRCMCs with a fixed fiber–interphase volume ratio exhibit nearly linear cross-property relations. While the random distribution and diameter of fibers have minimal effects on these relations, a decrease in interphase properties causes the cross-property curves to shift downward. The cross-property relation surfaces for CFRCMCs with varying fiber–interphase volume ratios are validated through finite element analysis. In summary, cross-property relations in CFRCMCs facilitate the prediction of challenging-to-measure physical properties from more readily accessible parameters, substantially simplifying material characterization. This methodology not only optimizes experimental workflows but also delivers a rigorous theoretical framework for multiphysics applications, particularly in extreme thermo-mechanical environments where coupled properties are critical to performance.

To mitigate vibration in thin-walled composite combustion liners of aero-engines, this study proposes an optimization strategy for stiffener design to maximize natural frequencies and suppress resonance. The approach enhances structural dynamics by installing transverse and longitudinal stiffeners along the tubular wall, with their dimensions and orientations systematically optimized. Design variables were chosen: combustion liner wall thickness, stiffener thickness, transverse stiffener width/angle, longitudinal stiffener width, and composite lamination layup scheme. The orthogonal experiments were completed and followed by range analysis and variance analysis. The results demonstrated that wall thickness had the most significant impact on the natural frequency, and the 45° lamination scheme showed a superior performance compared to other configurations. Finally, a predictive equation was developed using a multiple linear regression model. The optimized stiffener configuration markedly enhances natural frequencies, mitigating vibration-induced instability. This methodological framework provides a systematic basis for designing optimized stiffener layouts in composite combustion liners for aero-engines.