Tensile behaviors of Ti <sub>3</sub> C <sub>2</sub> T <sub>x</sub> (MXene) films
Shaohong Luo, Shashikant P. Patole, Shoaib Anwer, Baosong Li, Thomas Delclos, Oleksiy Gogotsi, Veronika Zahorodna, Vitalii Balitskyi, Kin Liao
Abstract
Abstract As the most representative member of a new emerging family of 2D material, titanium carbides or nitrides (MXenes), Ti 3 C 2 T x and its 2D assembly format, Ti 3 C 2 T x film, have displayed outstanding performance in a broad range of practical applications. However the mechanical behaviors of Ti 3 C 2 T x films are rarely reported. We report a systematic study of the tensile behavior of Ti 3 C 2 T x films. Ti 3 C 2 T x films with various thicknesses (2–17 µ m) were prepared by the vacuum filtration method. Quasi-static tension and cyclic tension tests were performed to investigate the deformation and fracture mechanism of Ti 3 C 2 T x films. It was found that: (1) the relative sliding between Ti 3 C 2 T x flakes is the dominant deformation mechanism of Ti 3 C 2 T x films. Cyclic loading-releasing in tension suppresses the inter-layer sliding of Ti 3 C 2 T x flakes effectively and thus the tensile strength of thicker Ti 3 C 2 T x film (5 µ m) film improves from 57 MPa to 67 MPa. (2) The mechanical properties of Ti 3 C 2 T x films are found to be thickness dependent. When the film thickness increases from 2.3 to 17 µ m, the tensile strength and elastic modulus drop from 61 to 36 MPa and from 17 to 8 GPa, respectively. This is interpreted as more structural defects presented in the through-the-thickness direction as film thickness is increased. (3) Moderate ultrasonication pretreatment (30 min) reduces the Ti 3 C 2 T x flake size significantly while improving the compactness of the Ti 3 C 2 T x film; and the resulting Ti 3 C 2 T x film shows a linear stress-strain relationship without plastic-like deformation. As a result, the tensile strength of 5 µ m thick Ti 3 C 2 T x film is enhanced to 85 MPa; (4) Structural defects of the Ti 3 C 2 T x film have significant effects on both the brittle-like fracture behavior and the distribution of tensile strength.