Fig. 1 Atomic structures and advantageous properties of MAX phase ceramics[6] With permission from Ref. [6] Copyright 2011, Annual Reviews

Fig. 2 Structure and mechanical, damping and friction properties of AZ91D-Ti2AlC composites fabricated by stir casting technique (a) Representative structure of as-cast AZ91D-Ti2AlC composite with white regions showing Ti2AlC phase[13]; (b) Tensile and compressive strengths of the as-cast composites with different Ti2AlC contents (A0‒A20 denoting the volume fraction of Ti2AlC from 0 to 20%)[13]; (c) Variations in the internal friction (Q-1) with strain amplitude[16]; (d) 3D structure of AZ91D-Ti2AlC composite after hot extrusion[14]; (e) Specific wear rates of as-cast and extruded composites compared to the AZ91D matrix under different applied loads[15]; (f) Wear morphologies of extruded composite after sliding along parallel (∥) and perpendicular (⊥) directions with respect to the extrusion axis[15] (a, b) Adapted with permission from Ref. [13] Copyright 2017, Elsevier; (c) Adapted with permission from Ref. [16] Copyright 2019, Elsevier; (d) Adapted with permission from Ref. [14] Copyright 2018, Elsevier; (e, f) Adapted with permission from Ref. [15] Copyright 2019, Elsevier

Fig. 3 Structure, mechanical properties, and fracture morphologies of 2009Al-Ti3AlC2 composites made by powder metallurgy technique[17] (a) Structure of 2009Al-Ti3AlC2 composite after extrusion and inverse fast Fourier transformation image of interface between Ti3AlC2 particle and Al alloy matrix. TAC: Ti3AlC2; (b) Tensile stress-strain curves of the composites with different Ti3AlC2 contents; (c) Fracture morphologies of composite after tensile fracture; (d) Comparison of tensile strength and ductility of 2009Al-Ti3AlC2 composites with other 2xxx Al alloy composites reinforced by ceramics. Adapted with permission from Ref. [17] Copyright 2023, Springer

Fig. 4 Structural, mechanical and functional charateristics of Cu-Ti3AlC2 composites fabricated by powder metallurgy technique (a) Structure of Cu-Ti3AlC2 composite and its reaction layer between Ti3AlC2 (TAC) and Cu phases[20]; (b) Variations in the flexural strength and electrical resistivity of the composites as a function of the volume fraction of Ti3AlC2 phase[20]; (c) Wear rate of the composites against increasing sliding time with inset showing the dependence of wear rate on the volume fraction of Ti3AlC2 phase at a sliding time of 5 h[22]; (d) Surface morphology of Cu-25% Ti3AlC2 composite after arc erosion[20]. (a, b, d) Adapted with permission from Ref. [20] Copyright 2017, Taylor & Francis. The inset in (a) is adapted with permission from Ref. [21] Copyright 2007, Elsevier. (c) Adapted with permission from Ref. [22] Copyright 2019, Springer

Fig. 5 Structural, mechanical and electrical characteristics of Ag-Ti3AlC2 composites made by melt infiltration technique[27] (a, b) Structures of melt infiltrated Ag-Ti3AlC2 composites with different structural dimensions of micron- (a) and ultrafine (b) length scales with dark regions showing Ti3SiC2 phase; (c) Chemical characteristics of the micron-structured Ag-Ti3AlC2 composite; (d, e) Electrical conductivity versus Vickers hardness (d) and flexural strength versus fracture toughness (e) of the melt infiltrated Ag-Ti3AlC2 composites with other Ag-MAX phase composites fabricated by powder metallurgy technique. Adapted with permission from Ref. [27] Copyright 2023, Tsinghua University Press

Fig. 6 Structure, mechanical properties, and damping characteristics of nacre-like Mg-Ti3AlC composites[29] (a) Structure of nacre-like composite compared to natural nacre (of Sinanodonta woodiana shell, TAC: Ti3AlC2); (b) Compressive stress-strain curves of the nacre-like composite at different temperatures when loading parallel and perpendicular to its layered structure with inset showing bending stress-strain curve of the composite at room temperature (RT); (c) Variations in the internal friction (Q-1) with temperature and strain amplitude for the composite compared to the AZ91D alloy matrix; (d) Comparison of the specific flexural strength, i.e., flexural strength normalized by density, and fracture toughness of the composite with other materials. The structure of natural nacre in (a) is adapted with permission from Ref. [30] Copyright 2016, Elsevier. (a-d) Adapted with permission from Ref. [29] Copyright 2023, Elsevier

Fig. 7 Microstructure and mechanical properties of the hierarchical nacre-like Mg-Ti3AlC2 composites made by ice templating and melt infiltration techniques[31] (a) 3D structures of the composites with hierarchical nacre-like lamellar and brick-and-mortar architectures; (b) Ultrafine structure of the composite showing the preferential alignment of Ti3AlC2 platelets and full filling interspaces between platelets and metal phase in the ceramic-rich layer; (c, d) Deflected cracking paths in the composites with lamellar (c) and brick-and-mortar (d) architectures; (e) Rising R-curve behavior of the composites demonstrating stable crack propagation; (f) Variation in the flexural strength as a function of ceramic content in Mg and Mg-alloy composites reinforced with various kinds of ceramics; (g) Comparison of fracture toughness and flexural strength normalized by density for various metal-ceramic composites with nacre-like architectures. Adapted with permission from Ref. [31] Copyright 2023, Springer Nature