热交换器搪瓷界面过渡层结构研究

采用合理配方设计,使用一次涂搪工艺,制备出了同时具有优良的密着性能、热稳定性能和耐酸性能的热交换器(又称GGH,gas-gas-heater)搪瓷板.采用扫描电子显微镜和能谱仪对GGH搪瓷板进行界面过渡层显微结构分析和元素表征.显微结构分析表明:GGH搪瓷板界面存在过渡层,过渡层结构呈现咬合状.元素分析表明:搪瓷层和金属层间存在元素的相互扩散,在宏观性能上表现为GGH搪瓷板密着强度为1级,说明瓷釉层与钢板密着优良.     

低温钢板浴缸搪瓷密着机理研究

采用CoO、NiO、MnO_2、CuO、FeO等多种密着剂引入到低温钢板浴缸搪瓷釉,并以B_2O_3、TiO_2、Li_2O等部分取代SiO_2、Al_2O_3、Na_2O,研制出烧成温度低、密着性能优良的低温钢板浴缸搪瓷。通过扫描电镜和能谱仪分析,密着性能优良的低温钢板浴缸搪瓷界面存在搪瓷釉层与金属铁层相互镶嵌和Fe、Si、Co、Ni、Na、K、O等元素相互扩散的中间过渡层,中间过渡层的存在为低温钢板浴缸搪瓷产生优良密着创造条件。     

低温一次搪铸铁搪瓷研究

采用CoO、NiO、CuO、FeO等多种密着剂引入到铸铁搪瓷釉配方,采用三氧化二硼、二氧化钛等取代二氧化硅、三氧化二铝,研制出搪瓷烧成温度低,密着性能和搪瓷表面质量优良的一次搪铸铁搪瓷。     

低温一次搪铸铁搪瓷研究

采用CoO、NiO、CuO、FeO等多种密着剂引入到铸铁搪瓷釉配方,采用三氧化二硼、二氧化钛等取代二氧化硅、三氧化二铝,研制出搪瓷烧成温度低,密着性能和搪瓷表面质量优良的一次搪铸铁搪瓷。     

无铅建筑铝搪瓷的密着机理研究

采用扫描电子显微镜、电子探针等分析无铅建筑铝搪瓷界面的显微结构和元素分布，并结合铝搪瓷的密着强度，探讨了无铅建筑铝搪瓷的密着机理。结果表明，密着性能优良的无铅建筑铝搪瓷面存在铝元素与瓷釉元素相互扩散的中间过渡层；中间过渡层与金属铝的结合主要通过金属键来实现，中间过渡层与瓷釉层的结合主要是通过离子键和共价键来实现。     

超长搪瓷管制造工艺研究

超长钢管的涂搪和烧成是搪瓷行业的一项技术难题,本文研究开发了长度超过6 m钢管的涂搪和烧制工艺。采用搪瓷粉末静电喷涂(干搪),电阻炉预热和中频感应加热,成功研发出长度超过6 m的钢管搪瓷,得到的搪瓷钢管瓷层厚度均匀,管体挺直不变形,搪瓷表面光滑致密,耐酸、耐热冲击性能优异。超长的搪瓷管可用于极端环境,例如烟气换热器(GGH)。     

不同换热管用钢材的搪瓷密着性能研究

通过落球冲击法评价了低碳钢(20钢)和耐候钢(09CrCuSb)搪瓷密着强度,并采用扫描电镜和能谱仪分析了钢材与搪瓷结合层的微观形貌及成分。结果表明:低碳钢和耐候钢的搪瓷密着等级分别为2级和5级;低碳钢与瓷釉界面形成了锯齿状和枝晶状结构,界面粗糙,而耐候钢与瓷釉界面形成了脱离基体的岛状结构,界面较光滑;结合层主要成分均为Fe、Cu、Ni、Co元素;钢材与瓷釉之间形成粗糙的界面有利于提高搪瓷密着性能。     

一次搪耐酸瓷釉的研制

烟气脱硫脱硝所用的搪瓷换热元件必须具有较强的耐酸性和良好的导热性,因此一次搪耐酸瓷釉是首选。一次搪是将由瓷釉和磨加物制成的釉浆直接涂覆在脱脂处理后的金属表面,经干燥、烧成后得到既有底釉功能又有面釉功能的搪瓷涂层。论述了所研制的3种不同料性的一次搪耐酸瓷釉的理论依据,介绍了试验过程及测试结果。     

磨加超细二氧化硅对建筑搪瓷结晶和化学性能的影响

建筑搪瓷是近几年发展非常迅速的一种搪瓷材料,由于建筑搪瓷尺寸比较大,它不仅要求比较高的物理化学性能,而且工艺性能也要求比较高。本论文主要研究通过磨加法将超细二氧化硅引入到建筑搪瓷釉,对搪瓷釉二氧化钛结晶性能和耐酸化学稳定性的影响。研究结果表明,磨加一定量超细二氧化硅到建筑搪瓷釉中,不仅不会改变搪瓷釉的结晶性能,主晶相仍为锐钛矿晶体,而且建筑搪瓷的耐酸化学稳定性也有一定提高。     

低温无底釉耐酸搪瓷釉的研制

工业耐酸搪瓷釉大多在900～1000℃高温下烧成,同时需要在底釉上涂搪耐酸面釉.本文研制出的耐酸釉无需底釉,它起到底釉和面釉的双重作用,在850～880℃烧成,能减小搪瓷坯体烧成变形程度.瓷层密着成丝网状,瓷面具有良好的光泽度和致密度.经测定,这种瓷层在1%的硫酸溶液中煮沸2h,失重小于0.06mg/cm2,具有很好的耐酸性.     

低温覆铝锌钢板搪瓷的密着性能研究

通过对覆铝锌钢板搪瓷样品的密着测试,研究了搪瓷的密着性能。通过金相、扫描电镜等测试,分析了铝锌钢板搪瓷断面结合的微观结构,通过能谱测试分析铝锌钢板搪瓷的元素分布,探讨铝锌搪瓷的密着机制。结果表明,铝锌钢板搪瓷的密着性能良好,铝锌镀层与搪瓷层之间有明显的过渡层和元素扩散,中间过渡层与金属铝的结合主要通过金属键来实现,中间过渡层与瓷釉层的结合主要是通过离子键和共价键来实现。     

覆铝钢板搪瓷密着机理研究

通过对覆铝钢板搪瓷界面形貌、结构、元素分布等的分析 ,从化学反应动力学、热力学以及界面能探讨了密着机理 ,本质是界面化学反应产生络合物、氧化物以及合金相 ,并溶解在界面区瓷釉中 ,在界面形成的化学键使瓷层与基体紧密结合在一起     

Exploring the hindering mechanism of element Ti on the adherence of CoO-bearing one-coat enamel/steel

The effect of element Ti on adherence between a CoO-bearing single-layer enamel coating and steel was investigated. Falling-weights tests were carried out and cross-sections at interface of the enamel/substrate were analyzed with a scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS). Results show that addition of TiO₂ reduced adherence of the enamel coating by hindering the formation of anchor-like alloy precipitates. The decrease of anchor points lies in the following three reasons: I. The diffusion path of Co²⁺ ions to the interface was lengthened because of the blocking effect of rutile and the FeTiO₃ crystals; II. Formation of CoTiO₃ crystals leads to a reduction of free Co²⁺ ions; III. Co–Fe precipitates form away from the enamel/substrate interface, as FeTiO₃ crystals provide extra surface for the nucleation of Fe–Co alloy precipitates.     

覆铝钢板搪瓷的低温制备及其密着机理研究

研究了覆铝钢板搪瓷的低温烧成工艺,运用扫描电子显微镜观察了其界面形貌,发现在搪瓷层和金属层的界面形成了铁-铝-瓷釉的复合层。X射线能谱仪分析结果表明界面间的元素扩散十分强烈,并由此促进了覆铝钢板与搪瓷层形成良好的密着。     

提高锑钼底釉密着性能的研究

通过密着性能测试及扫描电镜（SEM）对搪瓷界面的形貌观察和能谱分析,研究了纳米Al2O3粉末对搪瓷锑钼底釉密着性能的影响。结果表明,一定量的20～30nmAl2O3粉末的加入能够提高锑钼底釉的密着性能,并扩大搪瓷的烧成温度和烧成时间范围。     

Nature of Adherence of Porcelain Enamels to Metals

An investigation of the fundamentals of the adherence of porcelain enamels to metals indicated that good adherence is the result of metal-to-metal bonds between the atoms in the base metal and the proper metallic ions in the enamel. To accomplish this type of bond, the enamel must meet certain chemical and thermodynamic requirements: (1) The enamel at the interface must be saturated with an oxide of the metal and (2) this oxide must be one which, when in solution in the glass, will not be reduced by the metal. In the case of iron, the oxide is FeO. Many of the phenomena observed in commercial enameling were investigated and found to be related to adherence, but not essential for its development. An example is the precipitation of metallic particles in the enamel. Much of the complexity in commercial enameling arises from the limitations imposed by practical considerations. For example, because enamels usually are fired in air, the heavy scale developed during the early stages of firing must be removed before adherence can be developed. Likewise, as the conditions of the enamel-metal interface change rapidly during firing, "adherence-promoting oxides" are used to help maintain the necessary conditions for the time required in commercial enameling. Surface roughness, although not necessary for excellent adherence, was found to improve the apparent adherence when the bond between the enamel and the metal was relatively weak.     

Microalloy Precipitation at the Glass–Steel Interface Enabling Adherence of Porcelain Enamel

The adherence of vitreous enamels on steel plates is studied clarifying the mechanisms taking place at the interface during firing. Evidence is provided from electron microprobe analysis for an iron alloy precipitation at the interface, which results from oversaturation of ferrous iron in the enamel glass. Subsequent coalescence of the alloy particles is observed but only after their bonding to the base metal adherence after cupping is achieved. The formation of microalloys requires Co²⁺, Ni²⁺, and Cu²⁺ ions in the enamel glass. A selective dissolution of the base metal by the latter cations does not occur.     

瓷釉涂层/金属基体界面分形维数的研究

研究瓷釉涂层和金属基体界面形貌的分形特征,建立了分形曲线的提取模型,用计盒维数法计算分形维数,并和落球冲击试验结果相比较,发现分形维数的变化和瓷层的密着性的好坏呈现相同的变化趋势.分形理论为研究喷瓷管道的密着性提供了一种新的方法,为深入研究瓷层的密着性奠定了基础.