A strong, lightweight, and damping cermet material with a nacre-like ultrafine 3D interpenetrated architecture

Abstract

While materials that are light, strong, tough and simultaneously damping are highly attractive for a range of applications, it remains a challenge to achieve a combination of all these properties in a single material as these properties are often mutually exclusive. Here we present a cermet material comprising an ultrafine-grained Mg-Al-Zn magnesium alloy with ultrafine Ti3AlC2 ceramic platelets, where the two phases are bi-continuous and interpenetrated in 3D space yet are alternately arranged in a layered fashion as in natural nacre. Such an architecture was constructed by infiltrating the alloy into the porous ceramic scaffold where the Ti3AlC2 platelets were preferentially aligned by vacuum filtration and partially sintered. The resulting cermet exhibits a high flexural strength exceeding 1 GPa and a high specific flexural strength (strength normalized by density) of over 350 MPa/(g cm−3) – both exceeding those of most other bulk magnesium (and magnesium alloys), ceramics, and their composite materials – as well as high damping capacities and good fracture toughness. The architectural design strategy and the robust fabrication approach may prove to be effective for developing new high-performance cermet materials.

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