Materials that are classed as ceramics are non-metallic. They are primarily oxides, but can also be carbides, nitrides, borides, and silicides. They can be single compounds or mixtures of several different compounds.
Clay ceramics and stone have traditionally been used as structural materials. More recently, these ceramics have been replaced by concrete which is a complex ceramic composite.
Ceramics have also been developed to be used in electronic, computer, communication, biomedical and aerospace applications.
Ceramics and glasses have a wide range of mechanical and physical properties, but most are hard and brittle. Ceramics contain flaws caused by processing and preparation. These flaws make ceramics brittle materials and often result in premature failure. The flaws are variable in size and number, leading to variable mechanical behaviour.