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Cholerny Spammer
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 Posted: Tue 8:18, 28 Dec 2010 Post subject: tory burch flats Willemite crystalline glaze _2660 |
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Willemite crystalline glaze
847-1852 years. 1906, Riddl systematically studied by the 1050 ~ l1 (510 ℃ sintering of boron-containing zinc frit, and outlines the composition of its crystallization of the glaze. He made zinc crystalline glaze recipe (wt%): 27.389znO, 7.382KN, 13.770 borax, 7.200 chalk,[link widoczny dla zalogowanych], 4.466 boric acid, 39.693 flint, 0.6CuO (more than 100% excluded). This is consistent with the chemical composition of the glaze (%): 2 .6535 Na20, 4.0773K2O, 4.7839CaO, 32.476znO, 47.0662Si02, 8.9424. Riddl that add the coloring agent 03, CuO,[link widoczny dla zalogowanych], MIl0 willemite crystallization will not significant impact, its introduction precipitation even after the white willemite crystals, but some basic changes in the background of glass enamel. 1937, the United States NortonFH zinc glazes studied in detail the nucleation and crystal growth kinetics. The glaze formula is as follows: 0.0513 № O ・ 0.2350O ・ 0.0880CaO ・ 0.5750ZnO ・ 0.0513BaO.0.1620Aq ・ 1.7000Si02 ・ 0.202oTi02 and 0.25% CoO additives. In addition to 03, CaO, and si, all components are pre-melting . In the course of the study, NortonFH enamel samples placed first in the electric furnace (temperature range is ± 2 ℃) heated to l27o ℃, heat 30mln, and then rapidly cooled to different temperatures and heat lh, and then he determined by a precipitation , b, c, d are four types of crystal number and maximum size, access to the crystal nucleation rate and growth rate and the temperature curve. NortonFH that, a main crystalline phase is to avoid the formation of willemite matt glaze and access to granular crystal ball is too coarse a,[link widoczny dla zalogowanych], a large number of nuclei should be heated to dissolve the glaze of high temperature (higher than the crystal growth temperature range), while the temperature dropped to 28 after the crystal growth temperature and thermal insulation. NortonFH also believe that the crystal growth temperature the crystal shape, the composition of the glaze, the introduction of certain additives (such as Na2CO3,[link widoczny dla zalogowanych], CaCO3) as catalyst Jing crystal growth temperature can change the local viscosity of the glaze melt. This will achieve the controlled crystallization of willemite. As Glaze limits the thickness of the crystal growth only in the glaze layer plane. Therefore, NortonFH very concerned about the precipitation of the crystalline lens and that only the hexagonal crystal ball to output larger size particles formations. NortonFH paper for later The basis of the research field. His research method and is still the main conclusions of the theoretical basis of crystalline glaze. However, due to the lack of more advanced research methods, NortonFH set to precipitate crystals of four kinds of qualitative analysis,[link widoczny dla zalogowanych], nor fully confirmed the results of their own, so he's somewhat speculative nature of some of the conclusions. In recent years, countries have increased attention on the extent of willemite glazes, the glaze composition of Aberdeen spider zinc crystal on silicon, silicon zinc pellets The structural features and the glaze firing system of China, Germany and Japan have industrial application of this glaze porcelain. willemite glazes are a ZnO-A arbitrage 02 a CaO (Mgo) a O (NO) system. According to some literature data, sub-willemite glazes firing: the heating temperature to mature (19_50-1350 ~ C), and then cooled to the temperature of crystal growth and preservation of the glaze firing should be smoke-free medium in the oxidation atmosphere, because reducing atmosphere volatiles from the zinc oxide in the glaze, resulting in the appearance of the glaze unsatisfactory. some countries researchers willemite structure and morphology of spherical particles were microscopic analysis, and overturned the NortonFH point of view - in the glaze layer the formation of coarse grains is based on the ball and glazed only on the direction parallel to the growth of willemite two hexagonal system. willemite crystal fiber needle-shaped structure to the relative configuration and cross beam in the form of C-axis direction (along the ceramic surface) growth. I-yin
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