Abstract
In order to obtain calcium mica–apatite glass-ceramics having high water resistance and excellent machinability, TiO 2 was added to the starting materials of glass-ceramics with chemical composition of 3:7 weight ratio of fluoroapatite to calcium–mica. A large number of fine spherical particles in which mica and apatite should be included were generated uniformly. The mica and apatite were crystallized at lower temperatures and at narrower temperature ranges than those in the undoped specimen. However, the crystallization quantity ratio of apatite to mica was smaller, compared with that of apatite to mica for the undoped specimen. These results suggest that TiO 2 acted as a nucleation agent of mica but impeded the crystallization of apatite. Mica in the fine spherical particles became plate-like when TiO 2 was separated at ⩾900 °C. The plate-like mica with size of 0.5–2 μm was surrounded by apatite, TiO 2 and residual glass, and formed the interlocking microstructure at 1000 °C. Such a microstructure resulted in high water resistance and excellent machinability. Particularly, a large number of fine TiO 2 particles surrounded the mica uniformly, which was very effective in the deterrence of disintegration.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.