Ceramic is a material that has been used for a long time for utilitarian and decorative purposes.
It is obtained from different raw materials present in the form of powder or paste, which are kneaded or molded to give them the required shape and then subjected to cooking, with which they acquire rigidity. Finally the ceramic pieces can be painted with enamel.
In the production of ceramic objects, inorganic solid materials, such as silica, alumina, kaolin and metal oxides, are always used in combination with other substances.
Ceramic is used in part for outstanding physical and chemical properties. Among them we can mention its stability, which allows it to avoid oxidation. Resists corrosion and abrasion, has no elasticity, is not combustible and is refractory.
Characteristics Of Ceramics
1. It is not combustible
Unlike wood, it is a much safer material for construction.
2. It is not oxidizable
It is highly stable, water does not alter it in the least.
3. Resistant to corrosion and abrasion
It is not affected by chemical substances, nor is it worn away by polishing.
4. Fragile or glassy
Although during the cooking it acquires hardness, the ceramic is a material that fractures in front of the tension efforts.
5. Not elastic
Once set, the ceramic remains fixed, it is no longer possible to mold it.
Ceramic in general resists high temperatures (in fact it is obtained in ovens at temperatures exceeding 1000 ° C), but this property can be optimized by including in the mixture of the clays oxides of aluminum, beryllium and zirconium. In this case, the cooking is done at 1300-1600 ° C and a very slow cooling is carried out. In this way, products that can withstand temperatures of up to 3000 ° C, which are needed in quite specific applications, are achieved.
7. Not electrically conductive
In addition to the resistance to temperature, ceramic characterizes its great electrical insulation power.
The hardness of the ceramic is given mainly by its content in silicate or sand, but this at the same time reduces homogeneity; The fine grinding of the raw material helps in this regard.
9. Different types of ceramics
Porous ceramics: made with coarse-grained clay, they are rough and permeable to gases and fats; They absorb moisture. They are those that have not undergone the process of vitrification, not having been exposed to temperatures high enough to melt quartz with sand. Its fracture (when it breaks) is earthy. Bricks and tiles are considered porous ceramics.
Semi-compact ceramic: it has fine-grained clay, they are not very permeable and do not absorb moisture.
Compact ceramic: it has a microcrystalline structure, they are waterproof, soft and do not absorb moisture. Fine china and porcelain are located there.
Tenacious ceramics: they withstand high efforts. They are those that are used in the manufacture of tiles or porcelain, for example.
10. Important in the history of mankind
Objects made of ceramics are part of many cultures of the world and are significant when it comes to reconstructing the customs of a civilization that has already disappeared, as is the case with pre-Columbian civilizations.
Thanks to its durability, many objects made of ceramics and destined to daily activities (such as cooking elements, to transport water, etc.) or for use on special occasions, such as funerals, weddings, celebrations, have been collected in different archaeological surveys. rituals and others.