Structure and synthesis of MAX phase materials: a brief review

MAX phase materials a new family of ternary layered carbide and nitride compounds are represented by the general formula of Mn+1AXn, where n = 1 ∼ 3, M stands for early transition metal, A express A-group elements, and X is either nitrogen or carbon. As early as 1960s, this materials had been paied much attention due to their unique physical properties combination of metals and ceramics such as machinability, low hardness, excellent electrical, good thermal conductivity, damage tolerance, thermal shock resistance, high elastic moduli, oxidation and corrosion resistance. Therefore, MAX phase ceramics can be used as structural and functional materials, and is regarded as an ideal strengthening phase for metal matrix composites. Researchers have recognized the potentially technologically important application of this emerging material in the fields of aerospace, high-speed rail, nuclear industry, gas igniter, heat exchanger, high thrust rocket nozzle, electric brush, kiln furniture, metal refining electrode and high-temperature seal. In recent years, a new research caused heightened concerns on MAX phase, as the feasibility of attaining MXenes via selectively etching these and removing of the A-group element. In this review, the development of MAX phase and th e characteristics and applications of its derivative of MXenes are introduced in the first place. Next, the structure, morphology, electronic structure and diversity of the MAX phase are described. Thirdly, the different preparation methods and related applications of MAX phase films, bulk materials and powder materials are systematically introduced according to the current preparation technologies. Finally, the future development potential of MAX phase and the related improvement of the research subject are prospected. It aims to provide theoretical guidance and new ideas for synthesizing and creating new and excellent MAX phase materials, so that this new type of material can be put into social production and application in large quantities.