Fabrication of high-performance Magnéli phase Ti4O7 ceramics by in-situ hot-pressed sintering in a single step

Magnéli phase ceramics have gained extensive attention in a variety of fields, including batteries, electrocatalysis, and wastewater treatment, due to their distinctive properties. In this study, high-performance Magnéli phase Ti4O7 ceramics were synthesized by in-situ hot-pressed sintering of titanium (Ti) and titanium dioxide (TiO2) in a single step. The effects of the sintering temperature and Ti content on the phase transformation and morphology of ceramics were investigated. Moreover, the mechanical properties and electrical conductivity of the samples were systematically characterized. Results show that the sample with the Ti/TiO2 weight ratio of 0.09 sintered at 1000 oC has impressive comprehensive properties, including a high bulk density of 4.281 g·cm-1, a mean value of flexural strength of 125.58 MPa, and an excellent conductivity of 1129 S·cm-1. Furthermore, an evolution mechanism of the in-situ sintering for Ti/TiO2 was discussed based on the experimental data, and the pattern of variation observed by samples can be reasonably explained.