Affiliation:
1. Institute of Atomic and Molecular Physics Sichuan University Chengdu 610065 China
2. School of Chemical Engineering Sichuan University Chengdu 610065 China
3. Engineering Research Center of Combustion and Cooling for Aerospace Power Ministry of Education Sichuan University Chengdu Sichuan 610065 China
Abstract
AbstractTo date, the oxidation behavior of crystal materials is not fully understood; additional research is needed to understand the oxidation of materials. Herein, density functional theory (DFT) calculations and a 3D kinetic Monte Carlo (KMC) model are used to investigate the infiltration and diffusion behaviors of oxygen atoms within the crystal. Oxygen molecules readily adsorbes on crystal surfaces of the material and rapidly dissociates, verified by both first‐principles calculations and energy‐dispersive spectrometer (EDS) results. The infiltration ability of oxygen atoms into the inner crystal layers is affected by the surrounding oxygen atom, lattice compactness, and other factors. Energy‐barrier calculations show that crystal thin/dense layers have significant effects on the crystal oxidation process, so high‐pressure technology is used to investigate this correlation experimentally. KMC calculations and thermogravimetric analyses (TGA) show the infiltration behavior of oxygen atoms in the main crystal plane (211) toward the inner layers has the highest proportion to the actual high‐temperature oxidation behavior of the title material. The results of both the KMC calculations and thermal experiments show the material peeled off upon further oxidation, which accelerates oxidation. At the same time, high‐pressure treatment increases the oxidation resistance of materials at lower temperatures (<600 °C).
Subject
Biomaterials,Biotechnology,General Materials Science,General Chemistry