Elucidation of the crystallization behavior and the thermodynamics property of CuO/Bi12SiO20@ SiO2-B2O3-Bi2O3-CuO glass-ceramics

Abstract

Glass has good friction, lubricating properties, and great thermal stability, which has already made it to be widely used as excellent friction resistance and high temperature resistance materials for mechanical processing, and many other applications. In this study, SiO2-B2O3-Bi2O3-CuO (SBBC) system glasses were prepared via cooling the high temperature melt. The nucleation and crystal growth kinetics of SBBC system glasses were analyzed by thermogravimetric analysis and X-ray diffraction And then the value obtained was further analyzed by Gaussian fitting to give the temperature–time–transition (T–T–T) curve of SBBC system glasses under non-isothermal heating conditions. The crystallization kinetic parameters including the crystallization apparent activation energy (Ep) and the crystallization index (p) were also measured by the Ozawa and JMA methods (i.e. Ep1 = 116.4 kJ/mol, Ep2 = 50.1 kJ/mol, p1 = 3.7, p2 = 3.2). The effects of time(holding for 60 min), temperature (500 °C) and the phase of the precipitated crystal on the crystallization rate curves of SBBC system glasses were established. Furthermore, the crystal precipitation process of SBBC system glasses was verified by the typical crystal structure presented in scanning electron microscope (SEM) images, which successfully elucidated the working mechanism of the lubricating glass in high-temperature metal devices. The measurement of contact angles of the soften glass as well as the SEM-EDS analysis indicated that the early crystallization of SBBC glass has negative effect on the lubricating properties.