1. Liquid origin

1.1 Case of a pure product

A liquid may appear during the non-congruent melting of a pure product. This is either a solid solution or a peritectic melt. As the quantity of liquid formed is generally very large, this situation is rarely compatible with good control of the shape of the sintered part. Nevertheless, this type of liquid can be advantageously used to obtain dense ceramics in a few special cases, such as titanium carbides that are very sub-stoichiometric in carbon; non-congruent melting of the TiC solid solution _0.48 is observed at temperatures below 2,000°C (figure 1 ).