R2O-RO-B2O3-SiO2-Al2O3-P2O5-CaF2分相-析晶乳浊釉的形成机理

通过正交试验方法优化釉料组成和烧成工艺，制备了R2O-RO-B2O3-SiO2-Al2O3-P2O5-CaF2多元系光亮无锆的分相-析晶乳浊釉。采用X射线衍射仪、透射电子显微镜／X射线能谱、场发射扫描电子显微镜等研究了釉的显微结构及分相与析晶的形成机理。结果表明：析晶与分相结构并存，分相促进析晶；尺寸接近可见光波长的孤立液滴和所析出的钙钠长石晶体是釉面产生乳浊的根本原因。研究了不同烧成制度对分相-析晶乳浊釉显微结构的影响，发现缓冷釉样的分相液滴尺寸明显大于急冷釉样，急冷釉样中的第二相形貌表里存在明显差异，内部呈球形液滴状，表面则为蠕虫状。

FORMATION MECHANISM OF CRYSTALLIZATION-PHASE-SEPARATION OPACIFIED GLAZES IN AN R2O-ROL-B2O3-SiO2-Al2O3-P2O5-CaF2 SYSTEM

Bright crystallization-phase-separation zircon-free opaeified glazes composed of R2O-ROL-B2O3-SiO2-Al2O3-P2O5-CaF2 multi-components were prepared through the optimizing of the chemical composition of glazes and firing processing via the cross experimental design. The microstructure of the glazes and their formation mechanism of phase-separation and crystallization were studied by X-ray diffraction, transmission electron microscopy/energy dispersive spectrometry and field emission-scanning electron microscopy. The results show that crystallization coexists with phase-separation, which facilitates the crystallization and that the opaeification of the glazes results from both the isolated droplets in the glazes, with sizes close to the wavelength range of visible light, and lime soda feldspar crystals formed in the glazes. The effect of different firing schedules on the microstructure of the crystallized phase-separation opacified glazes was also studied. It was discovered that the droplets of slowly cooled glazes are remarkably larger than that of fast cooled ones, and that a sharp difference of the second phase shape occurs both on the surface and in the inner area of fast cooled glazes; spherical droplets were observed inside the glazes, and worm-like particles were found on the outside.