Rapid synthesis of bulk Ti₂AlC by self-propagating high temperature combustion synthesis with a pseudo–hot isostatic pressing process

Abstract

In this study, the dense polycrystalline Ti2AlC was synthesized by self-propagating high-temperature combustion synthesis with the pseudo–hot isostatic pressing process (SHS/PHIP). The resultant phase purity is highly dependent on the mol ratio of raw powders. The Ti2AlC was densified by applying pressure after the SHS reaction. The resultant sample mainly contains typical plate-like nonstoichiometric Ti2AlCx (x = 0.69) with grain size of ∼6 µm. The sample shows the Vickers hardness of 5.5 GPa, highest flexural strength of 431 MPa, compressive strength of 1033 MPa, and fracture toughness of 6.5 MPa·m1/2. No indentation cracks in Ti2AlCx were observed, indicative of a damage material nature. The reaction mechanism for the formation of SHS/PHIP-derived Ti2AlC is also discussed based on differential thermal analysis and x-ray diffraction results.

Cyclic oxidation behavior of TiC/Ti3AlC2 composites at 550–950°C in air

“…The experimental details can be found elsewhere [16]. By using the Rietveld method [17], phase quantification analysis confirmed that TiC concentration was 5% in volume. Samples were cut into rectangular bars with a dimension of 3 × 4 × 30 mm 3 from the central part of the bulk materials by the electrical discharge machining method.…”

High-temperature neutron diffraction and first-principles study of temperature-dependent crystal structures and atomic vibrations in Ti3AlC2, Ti2AlC, and Ti5Al2C3

“…Recent work in the literature suggests that Ti 2 AlC exists over a range of stoichiometries. For example, Bai et al recently reported the existence of a Ti 2 AlC x phase where x was as low as 0.69 [53,54]. Herein, it is more likely than not that the Ti 2 AlC is Al-deficient since it is believed that the loss of Al is what triggers the transformation to the 523 and possibly the 312 phase.…”

Macro-porous Ti2AlC MAX-phase ceramics by the foam replication method

“…With regard to the Ti 2 AlC MAX-phase material, the majority of research conducted to date is based on dense material [9,10,15,[24][25][26][27][28]. Hu et al [18] and Zhou et al [20] reported the production of porous Ti 2 AlC and Ti 3 SiC 2 respectively, prepared using NaCl as the pore former for controlling the volume fraction of porosity and the pore size.…”