We use cookies to enhance your experience. By continuing to browse this site you agree to our use of cookies. More info.

Glass ceramic materials were first developed at the Corning Glass Works and share properties of both the parent glass material and polycrystalline materials. In this article we look at how they differ from glass materials, how they are produced, some typical compositions and their applications.

When we think of glass materials, we tend to think of windows in buildings, houses and transportation. While this is true, many different kinds of glasses exist, with varying compositions.

Glass materials are generally transparent and very brittle (when not heat treated). The transparency is a result of the lack of grain boundaries and pores in the structure of the glass. This lack of grain boundaries also leads to the brittleness, as cracks can propagate unhindered.

Another characteristic of glasses is their lack of order on their structure i.e. the atoms and molecules are randomly arranged. This can be evidenced in an x-ray diffraction (XRD) analysis, where a glass will display no clearly defined peaks. A crystalline material on the other hand displays order in its structure and will generally produce well-defined peaks when analysed by XRD.

The lack of crystallinity in their structure leads to them being referred to as amorphous or vitreous.

Glass ceramic materials have the same chemical compositions as glasses but differ from them in that they are typically 95-98% crystalline by volume, with only a small percentage vitreous. The crystals themselves are generally very small, less than 1µm and most often very uniform in size. Furthermore, due to their crystallinity and network of grain boundaries, they are no longer transparent.

Glass ceramic materials are typically characterised by:

Glass ceramic components are formed using the same processes that are applicable to glass components. To convert them from a vitreous glass material into a crystalline glass ceramic material they must be heat treated or devitrified.

Devitrification can occur spontaneously during cooling or in service, but is most commonly incorporated to produce glass ceramics. It involves heating the formed glass product to a temperature high enough to stimulate crystals to nucleate throughout the glass. The temperature is then increased, which induces growth of the nuclei, crystallising the remaining glass.

Nucleation requires a critical number of atoms converging to form a nucleus. When the nucleus reaches critical size, nucleation occurs. In many glass compositions, nucleation is hampered by the fact the material is silica-based and highly viscous, making it difficult for the required atoms to come together. The crystal compositions can also be complex making nucleation difficult. These factors aid glass forming and cooling without crystallisation.

The devitrification heat treatment must be carefully controlled to ensure the maximum number of nuclei are formed and that these nuclei grow into a uniform fine crystal structure. In order to obtain a high concentration of nuclei throughout the structure, it is common to add a nucleating agent to the glass composition.

The most common nucleating agents are TiO2 and ZrO2. Other materials that have been used for nucleating agents include P2O5, platinum group and noble metals and some fluorides.

While many different glass ceramic compositions exist, there are 3 main families:

Some applications of glass ceramics include:

Please use one of the following formats to cite this article in your essay, paper or report:

Chai, Cameron. (2019, April 19). What is a Glass Ceramic?. AZoM. Retrieved on August 08, 2022 from https://www.azom.com/article.aspx?ArticleID=11110.

Chai, Cameron. "What is a Glass Ceramic?". AZoM. 08 August 2022. <https://www.azom.com/article.aspx?ArticleID=11110>.

Chai, Cameron. "What is a Glass Ceramic?". AZoM. https://www.azom.com/article.aspx?ArticleID=11110. (accessed August 08, 2022).

Chai, Cameron. 2019. What is a Glass Ceramic?. AZoM, viewed 08 August 2022, https://www.azom.com/article.aspx?ArticleID=11110.

Do you have a review, update or anything you would like to add to this article?

At the Advanced Materials Show 2022, AZoM caught up with the CEO of Cambridge Smart Plastics, Andrew Terentjev. In this interview, we discuss the company's novel technologies and how they could revolutionize how we think about plastics.

At the Advanced Materials Show in June 2022, AZoM spoke with Ben Melrose from International Syalons about the advanced materials market, Industry 4.0, and efforts to move toward net-zero.

At the Advanced Materials Show, AZoM spoke with Vig Sherrill from General Graphene about the future of graphene and how their novel production technique will lower costs to open up a whole new world of applications in the future.

This product Profile outlines the ZEISS SmartPI-Smart Particle Investigator.

Discover the OTT Parsivel², a laser disdrometer that can be used to measure all precipitation types. It allows users to collect data on the size and speed of falling particles.

Environics offers stand alone permeation systems that can be used for single or multiple disposable permeation tubes.

This article provides an end-of-life assessment of lithium-ion batteries, focusing on the recycling of an ever-growing amount of spent Li-Ion batteries in order to work toward a sustainable and circular approach to battery use and reuse.

Corrosion is the degradation of an alloy caused by its exposure to the environment. Corrosion deterioration of metallic alloys exposed to the atmosphere or other adverse conditions is prevented using a variety of techniques.

Due to the ever-increasing demand for energy, the demand for nuclear fuel has also increased, which has further created a significant increase in the requirement for post-irradiation examination (PIE) techniques.

AZoM.com - An AZoNetwork Site

Owned and operated by AZoNetwork, © 2000-2022