EVALUATION OF THE PHASE STABILITY, MICROSTRUCTURE, AND DEFECTS IN HIGH-ENTROPY CERAMICS AFTER HIGH-ENERGY ION IMPLANTATION

摘要

The location and distribution of atoms in the crystal lattice play a major role in controlling the mechanical and tribological properties of high-entropy alloy (HEA) ceramic materials. Herein, vacuum arc-deposited (TiZrHfVNb)N coatings have been implanted with 200 MeV xenon (Xe14+) ions at room temperature and fluences of 5 x 10(11), 5 x 10(12), and 5 x 10(13) ions/cm(2). The defect structure evolution of Xe-related defects and their effects on the structural, nanomechanical, and tribological properties of HEA nitride were characterized. The results show redistribution of lattice atoms and defects. Further-more, it is found that the decrease of the wear rate in the implanted coating (5 x 10(11) ions) from 9.7 x 10(-)6 to 4.85 x 10(-5) mm(3).m(-1).mN(1) has resulted from new defect combinations (vacancies, interstitial voids, and dislocations). Another source responsible for deterioration of properties was the breaking disorder of the elemental composition revealed by mapping the elemental composition by secondary-ion mass spectrometry (SIMS). These findings enhance the fundamental understanding of the high-energy irradiation effect on HEA ceramics.