Updated definition of glass ceramics
Abstract Glass ceramics are noted for their unusual combination of properties and manifold commercialized products for consumer and specialized markets. Evolution of novel glass and ceramic processing routes, a plethora of new compositions, and unique exotic nano and microstructures over the past 60 years led us to review the definition of glass ceramics. Well established and emerging processing methods, such as co firing, additive manufacturing, and laser patterning are analyzed concerning the core requirements of processing glass ceramics and the performance of the final products. In this communication, we propose a revised, updated definition of glass ceramics, which reads "Glass ceramics are inorganic, non metallic materials prepared by controlled crystallization of glasses via different processing methods. They contain at least one type of functional crystalline phase and a residual glass. The volume fraction crystallized may vary from ppm to almost 100%"