Ceramics. Characteristics and Technologies

Ceramics are everyday materials that are very familiar to the general public. They are present in many everyday objects, from the highly visible, such as tableware, to the more hidden, such as in our computers and cell phones, where they are an essential component of the electronics.

The production sector and, upstream, the research sector are very active. They generate sales that are difficult to estimate precisely, but which are colossal, probably in excess of 100 billion dollars a year worldwide.

University libraries contain hundreds of works dedicated to this subject, and its industrial importance has led Techniques de l'Ingénieur to devote an entire volume to it, comprising dozens of detailed contributions. The scientific and technical field covered by ceramics is so vast that it is often difficult to find one's way around and get an overview. Yet this is the aim of this work: to provide, in a volume limited to a few pages, the main elements for identifying ceramic materials among other kinds of materials, so that the reader can get an idea of their specific features and technologies, and also better understand why they have been the subject of so much study and development over the last fifty years.

Ceramics occupy a special place among materials, which are usually divided into three major classes on the basis of their many differences in composition, physico-chemical behavior, production methods and properties of use. These three classes are :

• metals and metal alloys ;

• organic materials (natural products such as wood, or synthetic products such as plastics);

• and ceramics.

From a practical point of view, the engineer who has to design this or that technical part in fields ranging from electronics to mechanics, from medicine to tableware, can't help but immediately ask the question: "What material or assembly of materials am I going to use? This is at the very heart of the engineering profession, where a wide variety of constraints are at play, not only technical, but also economic and even ecological... The answer is obviously to be found on a case-by-case basis, within the framework of the very broad possibilities opened up by the world of materials in general, and ceramics in particular, with a special mention for "ceramic composites" (combinations of materials for certain specific uses, notably in the case of ceramic coatings).

This article is therefore in no way a treatise on ceramics – impossible to achieve in just a few dozen pages – but is simply intended as an introduction to this multi-faceted branch of materials science. Initially, the aim is to provide...