Abstract: By optimizing the composition and microstructure, a new mica glass-ceramic with excellent machinability
was obtained. For this kind of mica glass-ceramic, a continuous band chips can be formed in machining at a high velocity and cut depth after
crystallizing at 650℃ and containing 40vol% of mica crystals (the rest is a glass phase), while the flexible strength reaches to 150MPa.
The test results show that the mechanism of ductile-mode material removal of the brittle material is attributed to a combination of mica crystal
guidance for crack propagation and the ability of glass phase to produce intense shearing strain. The further crystallizing at 750℃ can
enhance the flexible strength to 210MPa with increasing the amount of crystalline phase after cutting.

Key words: mica glass-ceramic, microstructure, ductile-mode material removal