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。     

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。     

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.     

覆铝钢板搪瓷的底材化学处理

研究了覆铝钢板复合材料的表面化学状态与搪瓷密着性的关系,认为表面的组织状态与结构对搪瓷密着性有很大的影响。实验得出,铬浴处理后的覆铝钢板表面活性强,组织结构适合瓷釉元素的扩散,搪瓷界面过渡层宽度增加,密着强度提高。     

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。     

新型覆铝钢板搪瓷的研究进展

新型覆铝钢板搪瓷主要由覆铝钢板和搪瓷层两部分组成,具有优良的物理、化学性能,国外已广泛应用于建筑、家电、科教、卫生用品等行业.研究覆铝钢板、搪瓷瓷釉以及密着机理是解决当前覆铝钢板搪瓷问题的重点.     

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。     

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     

氧化镍在搪瓷密着及抑制鳞爆中的作用

0 引言 金属和瓷釉的组合扬长避短,就形成了搪瓷。它兼备了金属的强度和瓷釉的华丽外表以及耐化学腐蚀的性能。然而,金属和搪瓷是两种不同组成、不同结构性能各异的材料。金属与瓷釉的牢固结合是一个极其复杂的物理化学过程,加之同一材料在不同的条件下所表现的形式也会不同。对此学者们见解各异,众说纷纭,提出了不同的密着机理与机制。众所周知,搪烧前在钢板表面沉积一层镍或是过渡金属氧化物如CoO,NiO和MnO_22等,在适当的条件下,会与搪瓷钢板产生良好的密着。长期以来,国内外学者对钴镍底釉的密着机理作了很多研究。 Healy和Andrews研究表明含有氧化钻的搪瓷瓷釉能产生好的密着归功于被瓷釉溶解的钴和铁与瓷釉的亲密接触。Sweo和Pask强调CoO和NiO在瓷釉和金属密着中一个最     

一次搪耐酸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密着性能和耐酸性能的搪瓷板。采用扫描电子显微镜和能谱仪对一次搪耐酸搪瓷板界面显微结构和元素进行分析,研究结果表明,密着性能优良的一次搪耐酸搪瓷界面呈现咬合齿轮状,元素分析表明瓷层元素和金属元素相互扩散,相互渗透,在性能上表现为密着强度优良。     

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.     

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.     

涂层对速凝3D打印水泥砂浆力学性能的影响

3D打印砂浆普遍存在层间界面粘结较弱、抗折强度较低的问题,而膨胀水泥浆涂层涂覆于砂浆表面可产生表层压应力,进而提升其抗折强度,作为界面剂涂覆于层间可同时增强其界面粘结强度。本文通过将硫铝酸盐水泥与膨胀剂混合而成的涂层涂覆于速凝3D打印砂浆的表面与层间,研究了该涂层对不掺纤维及掺0.5%(体积分数)玄武岩纤维3D打印砂浆试件力学性能的影响规律。结果表明,涂覆层间涂层对无纤维与掺纤维速凝3D打印砂浆的层间界面粘结强度提升率分别为21.4%、12.2%,同时对其抗压强度也有一定提升作用。仅涂覆表面涂层与仅涂覆层间涂层对3D打印砂浆的抗折强度提升效果相当;同时涂覆表面及层间涂层对3D打印砂浆的抗折强度提升效果最显著,与无纤维、掺纤维的无涂层试件相比,提升率最高分别可达44.2%、23.2%。涂层对于无纤维3D打印试件层间粘结强度及抗折强度的提升效果优于掺纤维试件。     

Galvanic Corrosion Theory for Adherence of Porcelain Enamel Ground Coats to Steel

The galvanic corrosion theory of adherence between ground-coat enamels and steel was investigated as a part of a broad study of the bonding mechanism between ceramics and metals. The theory, which is outlined in this report, is based on the mechanical anchoring of the enamel into the pits formed by the galvanic attack of the enamel on the steel surface. The theory was first examined from the standpoint of the data on adherence obtained in earlier studies at the National Bureau of Standards. In addition, several experiments were performed which demonstrated that galvanic corrosion of the metal base could occur during the short firing times encountered in enamel processing. On the other hand, certain inconsistencies were observed in the data which indicated that the mechanism of galvanic attack followed by mechanical anchoring was not the only important factor affecting the bond strength.     

X-ray Diffraction Characterization of the Enamel–Steel Interface

In the enameling of steel, the oxide is generally regarded as being completely dissolved by the fusing enamel, with the enamel–metal bond forming directly between oxide-saturated glass and metal. According to this model, the adherence of the oxide layer present on the surface of the steel as the enamel begins to fuse is irrelevant, because none of the original oxide layer remains in the matured enamel–steel bond. This model has not been completely verified, however, and some researchers have presented evidence for the presence of a layer of wüstite (FeO) at the enamel–steel interface on the order of 1 to 4 μm in thickness. Whether such a layer exists has important implications regarding the mechanism of enamel–steel adherence. In the present study, a method was developed to concentrate whatever crystalline material might be present in the interfacial zone to make it more amenable to detection by X-ray diffraction. Through the use of wüstite standards, the present technique was shown to be capable of detecting a layer of wüstite at the enamel–steel interface as thin as 0.3 μm. However, in neither one-coat nor two-coat enameling could a layer of wüstite be demonstrated at the enamel–steel interface. Hence, there does not appear to be a 1-to-4-μm-thick wüstite layer at the enamel–steel interface. If a layer of iron oxide is present at the interface, it must be thinner than 0.3 μm.