Ceramics: The Oldest Class of Materials

As a continuation of the materials science basics topics, we are talking about the oldest class of materials, ceramics.

Before we jump into the oldest class of materials, if you want a brief overview of materials science you should check out the what is materials science post.

History of Ceramic Materials

Ceramics are the oldest class of materials. The technical definitions is an inorganic non-metallic material. Which just means they do not have carbon (inorganic) and they are not metals.

The word ceramics comes from the Greek words keramikos or keramos which means of pottery, pottery, clay, or tile.

Their oldest use dates all the way back to 24000 BC in Czechoslovakia. The ceramic artifacts discovered in Czechoslovakia were human and animal figurines. One of the most notable was The Venus of Dolni Vestonice. The artifacts discovered in Czechoslovakia were presumed ornamental. Therefore the first functional ceramic pottery discovered dates back to 9000 BC in Egypt. Last but certainly not least, the first use of the arguably most popular type of ceramic material, glass dates back to 1500 BC in Egypt as well.

Properties of Ceramics

Ceramic materials have excellent compressive strength (pushing down or squeezing) and hardness (resistance to indentation or scratching). However, as a tradeoff to their compressive strength if they are placed in tension (pulling) they can be very brittle.

Most ceramics are also good thermal insulators, electrical insulators, and non-magnetic. Which means that electrons do not travel through them very well. This is a result of the type of bonding in ceramics, ionic and covalent. There are some ceramic materials that have magnetic properties, however, generally, they are non-magnetic.

Due to the strength, hardness, and brittle nature of ceramics they are not easily formed or molded into parts at lower temperatures. This means in order to make ceramic parts like glass or cooking pots they must be made at very high temperatures to melt the ceramic, which is very expensive, or alternative methods must be used. This makes one of ceramics primary processing techniques kind of different from other materials

Processing of Ceramic Materials

One of the most common processes used to make parts out of ceramic materials is to harvest or mine them. After ceramics are harvested or mined they are converted into powders. The powders are placed into molds and then compressed and subsequently heated.

Compressed ceramic powders before heating, firing, or sintering are named green ceramics.

Green ceramics often contain water and binders hold the small ceramic particles in the part together.

Some of the names of common processing methods are extrusion, slip casting, pressing tape, casting, and injection molding.

Common Uses For Ceramics

Some of the most common uses for ceramics are glass, like the screen of your phone. Tableware and kitchenware are also made from ceramics because they have good thermal stability. This thermal stability is a result of their lack of thermal and electrical conductivity.

Let me know down in the comments below the ways you use ceramics in your everyday life and give this video a thumbs up if you learned something new.

That’s all I have for you today so until next time stay curious