Vitrification
Vitrification is an essential process in ceramics that involves the transformation of clay and vitrifying materials into a dense, hard, impermeable structure by exposure to high temperatures during firing. This phenomenon occurs when the components of the clay, mainly silica, alumina and feldspar, partially melt and form a continuous vitreous network that binds the ceramic particles together. Vitrification not only improves the mechanical strength and durability of the pieces, but also significantly reduces their porosity, making them suitable for holding liquids without leaking.
The degree of vitrification depends on the composition of the clay and the type of ceramic to be produced. For example, earthenware vitrifies at lower temperatures (between 1000°C and 1200°C), while stoneware and porcelain require higher temperatures (between 1200°C and 1400°C) to achieve complete vitrification. In addition to temperature, factors such as firing time and kiln atmosphere (oxidizing, reducing or neutral) also influence the degree of vitrification and the final properties of the piece.Interesting Fact
Vitrification was a key technological breakthrough that enabled the development of porcelain in China during the Tang dynasty (618-907 AD). The ability to vitrify clay at high temperatures was what set porcelain apart from other ceramics of the time, giving it its distinctive translucency and strength, which eventually made it a symbol of luxury and refinement around the world.Helpful Tip
To achieve optimum vitrification, it is essential to carefully control the firing curve, ensuring a gradual temperature rise to avoid thermal shocks that may cause cracks or deformation of the parts. In addition, use a thermocouple or a calibrated pyrometer to monitor the kiln's internal temperature accurately.