Rong Wang

Nickel-based superalloys are key materials for aerospace and gas turbine applications. Traditional manufacturing approaches struggle to produce controllable porous structures with complex topologies. This review focuses on additively manufactured porous Ni-based superalloys, and summarizes progress in porous structure design, including disordered, lattice, TPMS, bio-inspired, and AI-assisted structures. Common additive manufacturing technologies are introduced, along with their effects on microstructure evolution and defect formation. The review discusses non-equilibrium microstructures, elemental segregation, and typical defects such as lack-of-fusion, keyhole porosity, and residual stress, as well as their influences on strength, fatigue, and creep behavior. Post-processing strategies for defect mitigation and performance optimization are also summarized. This review highlights the unique mechanical and physical behavior of porous structures compared to bulk materials, with an emphasis on anisotropy, stress localization, and defect sensitivity. Finally, several critical and specific challenges are identified, including multi-scale modeling, microstructure control in complex topologies, fatigue prediction, and physics-constrained AI design. This review aims to provide a clear, focused, and structurally consistent overview of the current state of the field, and to support future research on additively manufactured porous Ni-based superalloys.

In recent years, there have been increasing research interests in investigating the compression and ballistic responses of metal-ceramic hybrid structures, mainly making use of the synergistic effects of conventional metal honeycomb structures and infilled ceramic matrix materials. In this paper, a novel hybrid auxetic re-entrant metal-ceramic lattice is designed and manufactured to overcome the intrinsic conflicts between the strength and toughness of architected mechanical metamaterials, synergistic effects of auxetic re-entrant metal honeycombs and infilled ceramic materials are experimentally and numerically studied, and auxetic deformation features and failure modes are characterized with the digital image correlation (DIC) technique as well. It was found that (1) the infilled ceramic matrix of conventional honeycomb frames only endure longitudinal compression or impact loading along the external loading direction, while auxetic metal re-entrant honeycomb components endure both longitudinal and transverse loading due to the negative Poisson′s ratio effect and (2) the collaborative effects of infilled auxetics and the constraint frames’ hybrid structure dramatically moderate the stress concentration state and improve the impact resistance of single-phase ceramic materials. Our results indicate that the auxetic hybrid design exhibits promising industrial application potentials for blast protection engineering.

In contrast to traditional materials, materials and structures with negative Poisson's ratio (NPR) transverse shrinkage (expansion) occurs under uniaxial pressure (tension). This characteristic makes NPR materials have many excellent advantages. Shear capacity and indentation resistance of NPR materials are introduced in this paper. According to these two characteristics, the paper also introduces the defence application of NPR materials.

Using a combination of finite element numerical simulation and experimental verification, the honeycomb structure with different parameters of negative Poisson’s ratio is compressed at a uniform speed. The influence of angle parameter θ, size parameter h and thickness parameter t on Poisson’s ratio and energy absorption of the whole structure is studied, and the main factors influencing Poisson’s ratio and energy absorption are discussed. The results show that the larger concave angle, the smaller size and the larger thickness of the honeycomb cell, the better energy absorption of the overall structure, and the angle is the parameter that has the greatest influence on the Poisson’s ratio and energy absorption. Meanwhile, it is demonstrated that the honeycomb hybrid auxetic material has better energy absorption.