Indian researchers develop transparent ceramics through ‘colloidal’ technique

Indian researchers have – for the first time – developed transparent ceramics through a technique called colloidal processing followed by simultaneous application of temperature and pressure.

The material can be used for thermal imaging applications, especially in harsh service conditions and personal protection systems such as, helmets, face shields, and goggles, a Ministry of Science & Technology release on Wednesday, September 15 said.

Transparent ceramics is a new class of advanced materials with unique transparency and excellent mechanical properties. These materials can be designed not only for transparent to visible light but also for ultraviolet, infrared, and radiofrequency, giving opportunity for diverse applications.

Though produced by different countries globally, transparent ceramics are restricted in supply as they can be used for strategic applications. Though several attempts were made in the country, the transparent ceramics produced were either on a laboratory scale or low transparency. “Currently the developed process is able to produce the sizes usable for several applications and on a pilot scale,” the release claimed.

Generally, prepared from the high purity powders through a line of critically engineered processing steps, transparent ceramics needs preparation processes that will help achieve theoretical transparency by eliminating defects. Chemical vapour deposition, involving reactions of the precursors in the vapour phase at elevated temperatures, and hot isostatic pressing (HIP) involving simultaneous application of temperature and pressure are a few advanced processing techniques generally practiced to address the above challenges. An enhanced diffusion process at high temperature under pressure is suggested as the possible mechanism to eliminate the defects.