What Is Enamel Fluxing Agent?
In the enamel frit formula, the purpose of introducing flux is to promote the melting of high melting point components at a lower temperature. Because many components in the formula have high melting points, such as SiO2, TiO2, etc., some other substances must be introduced to lower their melting points. Some of the introduced fluxes react chemically with them, and some can form with them Low temperature eutectic, thus lowering the melting temperature.
Diboron trioxide (B2O3) is not only a matrix agent but also a strong flux, which can make the enamel fine and smooth, and at the same time improve the bending strength, elasticity, thermal stability and chemical stability of the enamel. Sex is good.
The fluxing ability of PbO is also very strong. It can also improve the luster, chemical stability and resistivity of enamel, and can improve elasticity, but it is toxic, so it is generally not used in daily enamel except for color decoration.
It is necessary to introduce alkali metal oxides as fluxes in the formulation. However, due to the introduction of these oxides, the existing physical and chemical properties such as chemical stability, thermal stability, and electrical resistivity are reduced. Because during the heating process, the expansion coefficient of alkali metal ions is large, and these alkali metal ions are easily leached out from the porcelain layer, so the thermal stability and chemical stability are reduced.
Among the introduced fluxes, the decreasing order of the physical and chemical properties of the enamel is Li2O<PbO<K2O<Na2O. The more the amount introduced, the worse the physical and chemical properties of the enamel.
In formula design, more than two fluxes are often used at the same time, or a mixed flux made in advance is introduced, which can reduce the amount of flux and reduce the melting temperature of the enamel to the greatest extent. The extent to which the physical and chemical properties of the enamel can be reduced can be reduced.
The fluxing ability of PbO is also very strong. It can also improve the luster, chemical stability and resistivity of enamel, and can improve elasticity, but it is toxic, so it is generally not used in daily enamel except for color decoration.
It is necessary to introduce alkali metal oxides as fluxes in the formulation. However, due to the introduction of these oxides, the existing physical and chemical properties such as chemical stability, thermal stability, and electrical resistivity are reduced. Because during the heating process, the expansion coefficient of alkali metal ions is large, and these alkali metal ions are easily leached out from the porcelain layer, so the thermal stability and chemical stability are reduced.
Among the introduced fluxes, the decreasing order of the physical and chemical properties of the enamel is Li2O<PbO<K2O<Na2O. The more the amount introduced, the worse the physical and chemical properties of the enamel.
In formula design, more than two fluxes are often used at the same time, or a mixed flux made in advance is introduced, which can reduce the amount of flux and reduce the melting temperature of the enamel to the greatest extent. The extent to which the physical and chemical properties of the enamel can be reduced can be reduced.