An Overview of Parameters Controlling the Decomposition and Degradation of Ti-Based Mn+1AXn Phases

Materials

It-Meng Low¹ 

[1] Department of Applied Physics, Curtin University, GPO Box U1987, Perth, WA 6845, Australia;

关键词: MAX phases;    kinetics of decomposition;    activation energy;    vapor pressure;    Avrami equation;    Arrhenius equation;    damage-tolerance;   

DOI  :  10.3390/ma12030473

来源: DOAJ

【 摘 要 】

A critical overview of the various parameters, such as annealing atmospheres, pore microstructures, and pore sizes, that are critical in controlling the decomposition kinetics of Ti-based MAX phases is given in this paper. Ti-based MAX phases tend to decompose readily above 1400 °C during vacuum annealing to binary carbide (e.g., TiC_x) or binary nitride (e.g., TiN_x), primarily through the sublimation of A elements such as Al or Si, forming in a porous MX_x surface layer. Arrhenius Avrami equations were used to determine the activation energy of phase decomposition and to model the kinetics of isothermal phase decomposition. Ironically, the understanding of phase decomposition via exfoliating or selective de-intercalation by chemical etching formed the catalyst for the sensational discovery of Mxenes in 2011. Other controlling parameters that also promote decomposition or degradation as reported in the literature are also briefly reviewed and these include effects of pressure and ion irradiations.

【 授权许可】

Unknown