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I want to know something about the mechanical properties of the MAX phases. How ductile can $\text{Ti}_3\text{SiC}_2$ for example be at elevated temperatures? Can it be as ductile as Zinc or Aluminium?

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    $\begingroup$ For reference if anyone else was wondering what a MAX phase is. $\endgroup$ – Wasabi Feb 15 '17 at 18:28
  • $\begingroup$ Without doing any research, simply based on the stoichiometric notation, it's probably an intermetallic material, and so probably has approximately 0 ductility, as it would likely be brittle. That said, individual compounds could be different, or they could exhibit superplasticity at high temperatures, as does alumina (Al2O3) $\endgroup$ – wwarriner Feb 16 '17 at 3:08
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Relating to this link Mechanical properties of polycrystalline Ti3SiC2, I found that dense polycrystalline Ti3SiC2 samples were fabricated by reactively hot-isostatic pressing (HIPing) a mixture of elemental Ti, Si and C powders.

The mechanical properties, including load–strain response, bending strength, fracture toughness and crack propagation, were investigated from ambient temperature to 1573 K.

Non-linear stress–strain responses were observed in the polycrystalline Ti3SiC2 materials at ambient temperature. It is conceivable that the inelastic deformation is attributable to micro-deformations that consist of slip between micro-lamellae within individual grains and the formation of microcracks between grains.

The polycrystalline Ti3SiC2 exhibited a brittle-to-ductile transition at about 1473 K; above this the Ti3SiC2 samples deformed plastically and exhibited high strains (>1.5%), whereas below 1373 K only limited inelastic deformation was observed prior to fracture. The mode I fracture toughness, $K_{ic}$, was measured by the single-edge notched beam (SENB) method to be 4.52 MPa $m^2$ at ambient temperature.

Both fracture strength and fracture toughness decrease only slightly with increasing temperature up to 1273 K, above which they decrease more rapidly and reach half of their room-temperature values by 1473 K.

Now in regards of the comparison with Zinc and Aluminum, I am not certain about it but you can always search the properties of Zinc and Aluminum and compare them with the mechanical properties found in this link Titanium Silicocarbide ( Ti3SiC2 )- Properties and Applications

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These phases can be quite ductile due to their layered structure at the atomic scale, naturally as others have suggested here, it depends on compositions and stoichiometry. Under compressive conditions, high levels of performance can be achieved. This can be further enhanced by fabrication of metal-max phase composities. Generally, crack propagation is the failure mechanism in Max phase materials, which exhibit plastic deformation prior to fracture, unlike most ceramics systems.

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