Recent advances in transparent / translucent polycrystalline Sialon ceramics

The transparent polycrystalline ceramics have acquired an interest in different fields such as transparent armor windows, cutting tools, IR windows, wear and scratch resistant parts (watches, bearings, and displays), and synthetic opals and rubies. In recent years, the transparent ceramics are applied in lasers and high power solid state lighting as a luminescent material. Different types of transparent polycrystalline ceramics were reported for different applications. However, there are few transparent ceramics that can withstand the aggressive environment. Recently, some studies on optical properties of Sialon ceramics show that the Sialon ceramics would be suitable for the optical applications. Sialon ceramics are known for their excellent mechanical and thermal properties and applied as a structural ceramics. The Sialon ceramics have all those potentials that can overcome the mechanical and thermal limitations of existing transparent ceramics where a very high grade of transparency is not required. The reported Sialon ceramics are IR transparent and visibly translucent. The translucent Sialon ceramics can be applied as a phosphor ceramic plate (PCP) for high power solid state lighting (SSL). However, the fabrication and production processes are costly due to the high temperature synthesis and complex processing techniques. In this short review, we will discuss the recent trend, processing techniques, properties, applications, and prospects of transparent Sialon ceramics.