B_2O_3对R_2O-RO-B_2O_3-SiO_2-Al_2O_3系统快速烧成乳浊釉分相过程的影响

在R2 O -RO -B2 O3-SiO2 -Al2 O3系统中 ,通过设计合理组成 ,可以获得适合快速烧成的分相乳浊釉。本文用TEM/EDX ,DTA ,自动图像分析等手段研究了该系统中B2 O3组份的作用。结果表明 :为获得较高白度及良好釉面性状的低温快烧分相乳浊釉 ,少量B2 O3的添加是必需的。它具有扩大液 -液不混溶组成范围、降低Tb温度及釉烧温度、扩大釉烧温度范围、改善釉熔体的粘度 -温度特性等作用 ,有助于形成分相尺度合适的显微结构     

R_2O-RO-Al_2O_3-B_2O_3-SiO_2系统快烧自生乳浊釉的化学组成与分相行为

本研究选择具有大范围实用分相区、适合快速烧成的R2 O(K2 O ,Na2 O) -RO(CaO ,MgO ,ZnO) -Al2 O3-B2 O3-SiO2 系统 ,研究了该多元系统全熔块乳浊釉组成与结构间的相互关系。通过优化组成设计及物理化学过程的控制 ,使釉熔体在快速烧成过程中自发产生分相 ,形成微米 -亚微米级液 -液不混溶结构 ,从而产生良好的乳浊效果。本文对各氧化物对分相过程的影响进行了讨论。     

R2O—RO—Al2O3—B2O3—SiO2系统快烧自生乳浊釉的化学组成与分相行为

本研究选择具有大范围实用分相区、适合快速烧成的R2O（K2O,Na2O)-RO(CaO,MgO,ZnO)-Al2O3-B2O3-SiO2系统,研究了该多元系统全熔块乳浊释组成与结构间的相互关系,通过优化组成设计及物理化学过程的控制,使釉熔体在快速烧成过程中自发产生分相,形成微米-亚微米级液-液不混溶结构,从而产生良好的乳浊效果。本文对各氧化物对分相过程的影响进行了讨论。     

R2O-RO-SiO2-B2O3-Al2O3系统乳浊釉的制备及微观结构分析

通过调整配方组成,成功制备了R2O-RO-SiO2-B2O3-A12 O3多元系统无锫乳浊釉,重点探讨了釉料化学组成关系对釉面乳浊程度的影响,采用扫描电子显微镜(SEM)研究了釉层微观结构及釉层乳浊机理.结果表明:釉料组成中n(R2O)/n(RO)、n(CaO)/n (MgO)、n(SiO2+ B2O3)/n(Al2O3)对釉面白度及质量影响显著.当n(R2O)/n(RO)在0.38～0.49、n(CaO)/n(MgO)在1.03～2.19、n(SiO2+ B2O3)/n(Al2O3)在12.69 ～18.42范围时,釉面自度高、质量好.釉面乳浊的原因是由析晶与分相共同作用,分相促进了晶体的析出,晶体形状主要为短柱状,尺寸约1～4 im,并以类球状团聚包裹形式分散于釉层中.     

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。     

R2O-RO-B2O3-SiO2-Al2O3-P2O5-CaF2系分相-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.     

快速烧成低锆固-液复相乳浊釉的研究

本研究选择K2O-Na2O-CaO-MgO-ZnO-Al2O3-B2O3-SiO2多元系统,不添加或添加少量超细硅酸锆,通过优化组成设计及物理化学过程的控制,使釉熔体在一次烧成过程中形成分相-微晶的复相结构,实现平滑光亮的釉面外观,应用SEM,TEM,EDS,XRD等方法,对K2O-Na2O-CaO-MgO-ZnO-Al2O3-B2O3-SiO2多元系统中所设计组成点的瓷釉物相及显微结构进行了研究,指出釉层中大量的分相液滴是造成乳浊的原因,研究了添加少量 硅酸锆对分相过程的影响规律,通过设计合理组成及快烧工艺,可得到釉面综合质量良好的固-液复相乳浊釉。     

R2O-RO-Al2O3-SiO2-P2O5系分相/析晶乳浊釉乳浊粒子的形成机理

在普通石灰碱釉的基础上引入骨粉和滑石,形成R2O-RO-Al2O3-SiO2-P2O5系统釉料,通过调整釉料的化学组成获得分相/析晶乳浊釉.利用XRD,SEM,EDS等测试技术,研究了SiO2与P2O5和SiO2与MgO的摩尔比与釉层显微结构的关系,分析了乳浊粒子(玻璃液滴和微晶)的形成机理.     

0.20 R2O-0.45 CaO-0.35 ZnO-Al2O3-SiO2系统的相变

通过大量的配方实验,利用ＯＭ,ＴＥＭ和ＸＲＤ分析,研究了０.20R2O-0.45CaO-0.35ZnO-Al2O3-SiO2系统的分相与析晶,研究结果表明,在Ａl2O3含量高于0.30-0.45mole的区域可以获得乳浊程度和光泽度各异的析晶乳浊釉,在低铝区可获得分相乳浊和分相玻璃,且乳浊程度随Ａl2O3含量的降低,ＳiO2含量的提高而提高,用Ｎa2Ｏ取代Ｋ２Ｏ不利于系统的分相,试样中析出的晶体主要为硅锌矿,锌黄长石,白榴石笔锌铝尖晶石,当Ｒ２O全部由Ｋ２Ｏ引入且Ａl2O3含量较低时,主要为硅锌矿,白榴石和锌黄长石,Ａl2O3含量较高时则主要为白榴石,锌黄长石和锌铝尖晶石,用Na2O等摩尔取代Ｋ２O炒利于白榴石和硅 矿的析晶,而有利于锌黄长石的析晶,锌黄长石的析晶主要受组成的影响,对析晶保温度不敏感,通过设计合理的配方,采用适当的烧成温芳制度,可以获得结晶良好的析晶乳浊釉,分相乳浊釉,分相玻璃,硅锌矿或锌黄长石分相结晶釉或微晶玻璃。     

R20—RO—B2O3—SiO2—AI2O3系统快烧分相乳浊釉不混溶结构的形成及演变

本文选择R2O（K2O,Na2O)-RO(CaO,MgO,ZnO)-AI2O3-B2O3-SiO2系统中的典型组成,研究了在快速烧成条件下,该系列釉不混溶结构的形成规律。结果表明：不混溶结构中,深色相富Ca、Zn、Mg,贫Si、B、AI;浅色相则相反。较低（SiO2 B2O3)含量时,易形成三维连通结构;较高（SiO2 B2O3)含量时,则形成孤立液滴相结构。要使烧成的釉层的显微结构发展成为接近可见光波长范围尺度的分相结构、并得到光亮乳白的外观,以不混溶温度Tb稍低于釉烧温度较为合适。     

低温快烧自微晶乳浊釉的研究

采用ＳＥＭ、ＥＤＸ、ＸＲＤ等手段,了ＫＮａＯ－ＭｇＯ－Ａｌ２Ｏ－Ｂ２Ｏ３－ＳｉＯ２系全熔块乳浊釉的形成规律,指出釉层中均匀分布的大量ＭｇＳｉＯ３微晶是釉面乳浊的原因。组成中Ｂ２Ｏ３含量愈高,釉熔体的析晶倾向愈大。少量Ａｌ２Ｏ３则可以降低釉熔体高温粘度,抑制析晶,改善釉面面白我泽度。在釉烧过程中,析晶继续进行,Ｂ２Ｏ３含量的增加使基质釉玻璃的成熟温度降低。设计合理组成有快烧工艺,可得到釉面综合质量良     

自生分相乳浊釉的研究进展

对含磷与硼的自生分相乳浊釉的乳浊机理进行了分别概述,并简要介绍了这两种自生分相乳浊釉的研究进展,对分相乳浊釉良好的应用前景做了展望。     

R_20-RO-Al_2O_3-SiO_2-P_2O_5系分相／析晶乳浊釉乳浊粒子的形成机理

在普通石灰碱釉的基础上引入骨粉和滑石,形成R2O-RO-Al2O3-SiO2-P2O5系统釉料,通过调整釉料的化学组成获得分相／析晶乳浊釉。利用XRD,SEM,EDS等测试技术,研究了SiO2与P2O5和SiO2与MgO的摩尔比与釉层显微结构的关系,分析了乳浊粒子(玻璃液滴和微晶)的形成机理。     

FURTHER STUDIES OF PORCELAIN GLAZES MATURING AT HIGH TEMPERATURES1

The investigation covers three fields of glazes: Series A contains 21 glazes with variations in composition as shown in the formula . Series B contains 10 glazes, each having the formula but having their clay content varying triaxially between Florida kaolin, North Carolina kaolin, and Kentucky ball clay No. 4. Series C contains 20 glazes with variations in composition as shown in the formula . The method of experimentation consists of grinding the corner glazes of each series wet, for 18 hours, cross blending the corner glazes to produce the intermediate glazes, applying the glazes by dipping to green porcelain discs, and firing them in commercial periodic and tunnel kilns to temperatures between cone 16½ and cone 19 flat. The glazes were examined with the naked eye and a 10 X pocket lens. The triaxial replacement of CaO by MgO and BaO , as tested, makes practically no change in the appearance of the glazes. With the pocket lens the bubbles in the glazes appear smaller and more numerous, near the BaO apex. When fired in the periodic kilns for 42 hours the transparency of all the glazes in- creases with the temperature. The glazes fired in the tunnel kiln to cone 19 flat in 31 hours are more opaque and smoother than in the periodic kiln at three cones lower temperature. The triaxial replacement of the Florida kaolin, by North Carolina kaolin and Kentucky ball clay No. 4 produces relatively little change in the fired appearance. The glazes containing all ball clay or a mixture of ball clay and North Carolina kaolin overfire at a lower temperature than do those containing all kaolin or a mixture of Florida kaolin and ball clay. The best glazes with 0.2 K₂O and 0.8 CaO have approximately an alumina: silica ratio of 1:9 and 1:11 for the field covered. These glazes are generally more trans- parent than the glazes with 0.3 K₂O; otherwise the results are similar. The conclusions are : (1) that the nature of the firing conditions are of the utmost importance in the development of a glaze, and (2) that an intelligent choice between glazes of equally desirable appearance requires a resort to petrographic method and mechanical tests.     

Study on the phase-separated opaque glaze in ancient China from Qionglai kiln

Qionglai kiln is a famous folk kiln site in China. Six pieces of opaque green-glazed porcelain shards with mild gloss and jade-like feel fired in the Tang dynasty (618–907 A.D.), were adopted as test samples. The correlation among composition, microstructure, firing technique and glaze appearance has been investigated by means of energy-dispersive X-ray fluorescence, field emission electron microscopy, direct transmission electron microscopy, X-ray diffraction and refiring experiment. The study has demonstrated that the opaque green glazes from Qionglai kiln site are high-temperature calcia–magnesia–silicate glazes and typical of phase-separated glazes. The liquid–liquid immiscibility structure plays a key role for the artistic appearance of the glazes.