Machinable and chemically toughenable fluorine glass-ceramic

A fluorine mica glass-ceramic, comprising:

• SiO2:
• 25-75 wt %;
• Al2O3:
• 6-30 wt %;
• Na2O:
• 3-30 wt %;
• K2O:
• 0-15 wt %;
• B2O3:
• 0.1-30 wt %;
• MgO:
• 4-35 wt %;
• CaO:
• 0-4 wt %;
• F:
• 1-20 wt %;
• ZrO2:
• 0-10 wt %;
• P2O5:
• 0.1-10 wt %;
• CeO2:
• 0-1 wt %;
• SnO2:
• 0-1 wt %,
• wherein P2O5+Na2O>3 wt %, and Al2O3+Na2O+P2O5>17 wt %,
• wherein the fluorine mica glass-ceramic has a porosity of 0%, has greater than 40 Vol. % of crystalline phase and interlock crystallization structure can be formed, wherein the mica crystalline size is 5-100 μm, with an aspect ratio of <0.5, and
• wherein the glass ceramic has a microstructure comprising:
• 1). a glass matrix, and
• 2) at least one crystalline phase with the formula of (K,Na)1−xMg3(Al,B,P)1−xSi3+xO10F2, where x is 0 to 1,the glass ceramic is machinable and can be ion exchanged to achieve compress stress CS >300 MPa, and Dol >15 μm.

A fluorine mica glass-ceramic, comprising:

• SiO2:
• 25-75 wt %;
• Al2O3:
• 6-30 wt %;
• Na2O:
• 3-30 wt %;
• K2O:
• 0-15 wt %;
• B2O3:
• 0.1-30 wt %;
• MgO:
• 4-35 wt %;
• CaO:
• 0-4 wt %;
• F:
• 1-20 wt %;
• ZrO2:
• 0-10 wt %;
• P2O5:
• 0.1-10 wt %
• CeO2:
• 0-1 wt %;
• SnO2:
• 0-1 wt %,
• wherein P2O5+Na2O>5 wt %, and Al2O3+Na2O+P2O5>17 wt %, and,
• wherein the glass ceramic has a microstructure comprising:
• 1). a glass matrix, and
• 2) at least one crystalline phase with the formula of (K,Na)1−x Mg3(Al,B,P)1−xSi3+xO10F2, where x is 0 to 1,the glass ceramic is machinable and can be ion exchanged to achieve compress stress CS >300 MPa, and Dol >15 μm,
• wherein the fluorine mica glass-ceramic exhibits an Hv hardness higher than 200 kg/mm2.