Abstract
Given the unique nanolaminate structure,the MAX phase ceramics which are composed of alternatively stacked two-dimensional(2D)metal(M)carbides(X)and main group(A)atomic layers have shown promising properties at elevated temperatures.Recently,an excellent self-lubricating performance of a high-entropy(HE)(TiVCrMo)3AlC2 MAX is demonstrated at 800 ℃ in the air.However,the formation mechanism of a self-lubricative tribofilm is still waiting for clarified.In this work,the HE(TiVCrMohAlC2 MAX is synthesized and its oxidation behaviors are systematically evaluated at 800 ℃ in the air.A two-stage parabolic oxidation behavior is detected,which can be mainly ascribed to the volatilization of MoO3 species coupled with the thickening of the compound oxide scale.Meanwhile,the HE com-position results in chemically complex phases including Rutile and vacancy-ordered TiO species in the oxide scale,which contribute to a higher ion diffusion rate for mass transportation.Consequently,the continued volatilization of MoO3 is beneficial for the enhanced lubricity and anti-wear performance of the(TiVCrMo)3AlC2 MAX at 800 ℃.
基金项目
National Natural Science Foundation of China(52275212)
Fundamental Research Funds for the Central Universities(D5000230047)
State Key Laboratory of Solidification Processing(2022-TS-09)
NETL
NSTL
万方数据