Preparation and Properties of Ternary Ti₃AlC₂ and its Composites from Ti–Al–C Powder Mixtures With Ceramic Particulates

Abstract

A layered ternary carbide phase, Ti3AlC2, was synthesized by hot pressing from the starting materials of Ti, aluminum, and activated carbon at 1400°C for 2 h. Its composites were also fabricated through addition of micro‐sized SiC and partially stabilized zirconia particulates to the pulverized Ti3AlC2 powders. The polycrystalline Ti3AlC2 ceramic obtained has a flexural strength of 172 MPa and a fracture toughness of 4.6 MPa·m1/2, respectively. This compound is relatively soft (Vikers hardness of 2.7 GPa) and exhibits good electrical conductivity with an electrical resistivity of 8.2 μΩ·m. Both the Ti3AlC2/SiC and Ti3AlC2/ZrO2 composites are superior to the monolithic Ti3AlC2 ceramic in strength, fracture toughness, and micro‐hardness.

Electrochemical Reduction of TiO2/Al2O3/C to Ti3AlC2and Its Derived Two-Dimensional (2D) Carbides

“…In fact, Ti 3 AlC 2 has been found to be carbon deficient with respect to its ideal stoichiometry in the previous work, 40 and the influence of carbon content on the preparation of Ti 3 AlC 2 by using the conventional methods has also been investigated. 9,41,42 Figure 2 shows the current-time curve of the electroreduction process of the 3TiO 2 /0.5Al 2 O 3 /1.5C precursor. As shown in the figure, the current variation can be divided into two stages, i.e., the rapid decline and the slow decline.…”

“…can be used to prepare Ti 3 AlC 2 from pure metals (Ti/Al/C), carbides (TiC x /Al or Ti/Al 4 C 3 /TiC), and hydride (TiH 2 /Al/C). 4,[9][10][11][12][13][14][15][16][17] However, these processes are commonly performed under severe conditions, such as high temperature and high pressure. Furthermore, the conventional production of pure metals (such as Ti) usually suffers from the energy-intensive and tedious process.…”

Toughening Mechanisms in Nanolayered MAX Phase Ceramics—A Review

“…Transformation toughening in MAX phases can be traced back to 2007 [ 37 , 38 ]. A 20 wt % ZrO 2 /Ti 3 AlC 2 was obtained by uniaxial hot-pressing at 1450 °C under a pressure of 20 MPa for 2 h in vacuum and the measured fracture toughness of 20 wt % ZrO 2 /Ti 3 AlC 2 composite was 6.8 MPa·m 1/2 , while the fracture toughness of monolithic Ti 3 AlC 2 was 4.6 MPa·m 1/2 [ 37 ].…”

“…Transformation toughening in MAX phases can be traced back to 2007 [ 37 , 38 ]. A 20 wt % ZrO 2 /Ti 3 AlC 2 was obtained by uniaxial hot-pressing at 1450 °C under a pressure of 20 MPa for 2 h in vacuum and the measured fracture toughness of 20 wt % ZrO 2 /Ti 3 AlC 2 composite was 6.8 MPa·m 1/2 , while the fracture toughness of monolithic Ti 3 AlC 2 was 4.6 MPa·m 1/2 [ 37 ]. The SEM observations of the fracture surface indicated that the fracture toughness improvement can be ascribed to the compressive stress in the matrix generated by the ZrO 2 particles transformation process.…”

Strengthening Ti3AlC2 by In Situ Synthesizing Ti3AlC2–Y4Al2O9 Composites

“…Second phase particles, such as Al 2 O 3 , TiB 2 , and SiC reinforcing particles have been incorporated to strengthen the Ti 3 AlC 2 matrix . As the Al 2 O 3 and SiC particles did not react with the Ti 3 AlC 2 matrix during composite processing, the interfaces are weak and only limited strengthening can be achieved.…”