17 display bone China defects

To overcome the way: ( 1) Adjust the bone porcelain glaze formula, should be very careful in making use of raw materials, pay attention to in the bone porcelain glaze should not be mixed with the colored metal, such as: titanium, manganese, cobalt, nickel, etc. , so as to avoid mixed molten material and other colors. ( 2) Burned bone porcelain body, should pay attention to clearing the bone porcelain of clutter and dirt on the surface of the billet. ( 3) Oxidation in the process of burning stage, when the temperature reaches 901000 ℃, the heat preservation but under the temperature below 900 ℃, be calm carbon burning process, at this stage to fully to oxidation, pure oxygen through the so-called oxygen, small air and gas in high temperature bone porcelain glaze vitrified net in the front row. Reduction is not too early to start on reducing flame firing at 1000 ℃. But to prevent the reduction more carbon AD cool-headed, make porcelain body with yellow. To make calm in glaze or carbon on the surface of the billet surface, in and bone porcelain body has not yet been sintering and cases burn with many pores. If let it to the bone China shaft when molten still residual carbon, the carbon sink at high temperature, after bone porcelain glaze melt, because of the relationship between carbon dioxide and water decarburization reaction and produce gas became the real causes of bubble defect. Calcination celadon to burning under strong reducing atmosphere. According to the practical experience, weight reduction, the CO concentration, such as in a 6 - The range of 10%, firing celadon of pure tone can be obtained. 11, axial surface pinhole meaning: also known as brown eyes. Bone China color glaze surface of holes, defect pores, produced in the bone porcelain glaze preparation, bone porcelain glazing and firing process causes: ( 1) Bone China special mud treatment raw materials, including organic matter too much, coarse particles, large water rate. Inadequate stale period short, kneading, porosity is large, the bone porcelain body even glaze, and when in the high temperature melting is absorbed by the bone porcelain body porosity caused the pinhole. ( 2) Bone porcelain glaze in the heating process, the following will happen in a series of complicated physical and chemical reaction and dehydration, solid phase reaction, the decomposition of carbonate and sulphate. Part of eutectic material, raw material melting and melt dissolve each other, some volatile raw material and the interactions between bone porcelain glaze billet, etc. , at the same time of reaction, the bone porcelain glaze began to sintering, melting and spread out is smooth glaze on the bone porcelain blank. Bone porcelain glaze in the decomposition, volatile dehydration process is likely to lead to bone porcelain glaze defects such as brown eyes, but with different extent of all kinds of raw materials. Such as boric acid, borax, aluminum hydroxide, hydrated lime, clay and red lead with dehydration or decomposition reaction in heating, even a small amount of water and decomposition residue and the high temperature to the net. But most of the gas at low temperatures, the discharge and feldspar materials although itself does not crystallization water, but because in & gt; 800 ℃ will release a lot of various gas adsorption, such as water vapor, acidic gas such as N2 or CO, so the feldspar easily formed in the bone porcelain glaze brown eyes. Bone porcelain glaze in the carbonate ( Especially the limestone) Too much, the high temperature time for carbonate decomposition, after escaping gas pores. And as easy to absorb carbon and carbide in lime glaze firing, the absorbed carbon with the increase of temperature and burning to leave a pinhole. — Bone China gift wholesale to be continued. 。 。 。 。 。