无机粉体材料的表面处理方法

无机粉体材料的表面包覆及改性是近年来冶金及材料界为寻求制备新型材料而涌现的一个新的研究领域。粉体材料经无机包覆后，表面可具有新的物理化学性质，制成的复合粉体可用于陶瓷、催化、防腐、颜料、粘结、电子等行业。本文对无机粉体材料的表面处理方法进行了详细综述。     

一种改性粉煤灰高产率制备高纯莫来石粉体的方法

<正>本发明公开一种改性粉煤灰高产率制备高纯莫来石粉体的方法,属于精细陶瓷技术领域。本发明包括以下工艺步骤:(1)在粉煤灰粉体中添加2~8%铝溶胶,经过球磨混合,实现粉煤灰粉体颗粒表面的包覆改性;(2)改性粉煤灰在一定温度下煅烧,使得粉煤灰中莫来石含量达到60~70%,实现粉煤灰粉体的莫来石化(mullitization);     

无机粉体/聚合物复合体系中的无机粉体表面改性技术研究进展

阐述了无机粉体/聚合物复合体系中的无机粉体化学包裹表面改性技术研究进展,重点介绍了化学包覆表面改性的影响因素、无机粉体材料的选择和化学包覆改性剂的选择。对工业废弃物(如废弃石粉)用于无机粉体/聚合物复合体系,用以改善聚合物力学性能并降低成本,同时有效解决了工业废弃物的资源化利用问题进行了展望。     

纳米二氧化钛表面改性与应用研究进展

纳米二氧化钛作为一种重要的纳米材料,在陶瓷材料、催化剂载体等领域有着广泛的应用。在纳米二氧化钛粉体的工业化生产中,表面处理技术是必不可少的关键步骤之一,因为改性方法的选取以及包覆物的性质会直接影响产品的应用范围。在综合分析相关文献的基础上,概述了有关纳米二氧化钛粉体表面包覆的相关机理、方法和制备过程中的控制因素等内容;主要介绍了近几年世界纳米二氧化钛粉体表面改性的研究成果及进展,并提出了今后的研究方向。     

碳酸钙表面改性研究进展

介绍了碳酸钙粉体表面改性的方法——局部反应改性、表面包覆改性、高能表面改性及机械化学改性,对碳酸钙粉体表面改性的发展前景进行了展望。     

粒子复合技术在材料制备技术中的应用

粒子复合技术是一种新型的粉体表面处理技术,它可以实现子粒子对母粒子的包覆处理,将多种粉体进行复合,从而开发出许多新型的功能复合化粉体,为新材料的研制开发提供了新的技术途径。本综述了这种粒子复合新技术在材料制备技术中的应用,并就粒子复合技术的应用前景提出了一些展望和见解。     

注浆成型碳化硅陶瓷材料成型工艺研究

碳化硅陶瓷材料是共价键极强的耐高温新型陶瓷，具备优良的综合物理化学性能，近年来已广泛应用于高新技术领域。本文采用注浆成型工艺制备高固含量低粘度碳化硅陶瓷，分析了注浆成型碳化硅陶瓷的工艺过程，粉体包覆改性，浆料制备，注浆素坯成型。为注浆成型碳化硅陶瓷相关研究提供一定的理论参考。     

Si3N4粉体的表面改性及其对立体光刻成型的影响

传统的陶瓷加工技术成本高、周期长、缺陷多,难以生产高性能陶瓷,立体光刻技术是制造形状复杂陶瓷零件的一种高效手段。纯Si₃N₄粉体的折射率(n=2.1)与树脂(n=1.49)的折射率相差较大,光散射严重,导致其陶瓷浆料的固化深度较低,很难直接利用立体光刻技术成型Si₃N₄陶瓷零件。为解决Si₃N₄粉体难以光固化的难题,本研究采用表面包覆有机物和表面氧化两种方式改性Si₃N₄粉体,并对比两种方式对Si₃N₄粉体光固化特性的影响规律。结果表明,包覆实验后,有机物单体经过一定反应时间后可均匀附着在Si₃N₄粉体表面;氧化处理后,Si₃N₄粉体表面形成非晶SiO₂层,该层均匀附着在粉体表面上。原始Si₃N₄粉体的固化深度仅为20 μm,经过包覆改性和800 ℃氧化4 h后,Si₃N₄粉体的固化深度分别可提高到40 μm和50 μm,两种方式均能有效提高原始Si₃N₄粉体的固化深度。     

硅溶胶包覆氧化铝陶瓷的抗热震性能研究

通过对表面包覆10 wt%硅溶胶的氧化铝粉体在不同温度下进行煅烧,并以不同温度煅烧后的粉体为原料制备陶瓷,探讨了硅溶胶包覆对氧化铝陶瓷烧结性能、力学性能以及抗热震性能的影响规律。结果发现,硅溶胶在氧化铝粉体颗粒表面形成良好包覆,这种完整包覆可以维持在900℃不发生变化;当煅烧温度超过1000℃时,部分硅溶胶从氧化铝表面剥落,形成细小颗粒填充在氧化铝粉体颗粒间的间隙,有效促进了陶瓷饱和体积密度的提高,从而使得陶瓷具有良好的抗弯强度,但其抗热震性能较差;当粉体的煅烧温度较低时,将获得多孔的陶瓷结构,可以有效提高陶瓷的抗热震性能,700℃煅烧过的粉体制成陶瓷,可以经受1200℃的热震11次。     

无机粉体表面包覆金属改性研究现状

无机粉体材料在化工、医药、电子、航空航天等领域有着广泛的应用。但随着现代科学技术的发展，各行业对材料有了更高的要求，单一的材料已很难满足特殊要求，因此无机粉体的改性就受到材料界的广泛关注，特别是粉体表面包覆金屑改性的研究。在总结了无机粉体表面包覆金属机理及遵循的基本原则的基础上，介绍了制备工艺，如固相法、气相法和液相法，并分析比较了各自的优缺点。重点分析了无机粉体材料（氧化铝、二氧化锆、钛酸钡、碳化硅等）表面包覆金属的研究现状，并指出其今后的发展方向。     

关注陶瓷材料在汽车上的热喷涂新技术

陶瓷材料热喷涂是一项具有广泛实用性的新型表面处理和表面强化的专业技术,具有许多金属材料无法比拟的优异性能,所以发展迅速,在许多领域发挥了越来越重要的作用。目前已在汽车及其他许多领域中成功应用,其技术的开发有着非常广阔的前景。针对陶瓷材料的喷涂新技术展露头角,介绍了陶瓷涂料的热喷涂技术及其工艺特点,分析了全新的陶瓷涂料及纳米陶瓷涂料的性能,研究了热喷涂工艺种类、特性和适用范围,同时指出了陶瓷热喷涂技术在汽车上的应用前景。     

Thermal insulation and antioxidation of vertical graphene oxide-grafted carbon nanofiber aerogels with ceramic coating

In this work, composite aerogels with low thermal conductivity and antioxidation were prepared by introducing graphene oxide (GO) on the carbon nanofibers (CNFs) surface, followed by ceramic coating. CNFs surface-grafted vertical morphology of GO was used as an enhancer to hinder the heat radiation transmission. The introduced shrinkage-resistant ceramic coating was used as an antioxidant barrier for carbon materials. The anti-shrinking ceramic coating was obtained by heat treatment of coating with wrinkle morphology to complete the ceramic transformation. The wrinkle morphology of the coating originated from the gradient crosslinking of the coating before its ceramic transformation. Among them, the gradient crosslinking of the coating could be done by irradiation crosslinking and crosslinker impregnation crosslinking. The thermal insulation and antioxidant of the composite aerogel were jointly investigated. Moreover, the mechanism of CNFs surface grafting GO and the anti-shrinkage mechanism of the coating were systematically discussed. The experimental results showed that the aerogel exhibited excellent thermal insulation and oxidation resistance in a wide range of temperatures. The structural design of the aerogel not only weakened the thermal radiation transmission to the CNFs aerogel but also significantly enhanced the antioxidant.     

铝合金表面陶瓷化对前处理的依赖性

结合等离子体增强的电化学表面陶瓷化技术原理，陶瓷膜的形成过程及特点，介绍了不同材质铝合金前处理工艺技术及主要特点，阐述了该技术对前处理的依赖性，根据陶瓷膜的不同用途及功能采取不同的前处理方法，突出了该技术的先进性。     

镁基材料表面微弧氧化生物医用陶瓷涂层研究进展

利用微弧氧化技术在镁基材料表面原位生成陶瓷膜层,能显著增强镁基材料的耐磨性、耐腐性、生物相容性等表面性能,在医用镁基材料表面改性中具有广泛的应用前景.本文主要对镁基材料表面微弧氧化所用的电解液组成、陶瓷膜的结构组成、复合生物涂层及其生物相容性的研究现状进行了评述,并对今后的研究前景进行了展望.     

含频率选择表面耐高温吸波涂层的高温吸波性能

耐高温电阻材料由于可调的表面阻抗使其兼具同向反射、损耗特性和宽频带等优异性能。本文通过刷涂法制备了含频率选择表面的耐高温吸波涂层,通过扫描电子显微镜和方阻测试仪表征分析了涂层的组分、微观结构和方阻的高温稳定性,通过矢量网络分析仪研究了涂层煅烧温度和煅烧时间对材料高温反射率的影响规律。结果表明,含频率选择表面耐高温陶瓷涂层经600 ℃长时间热处理后,表面形貌变化可控,表面方阻较为稳定,耐温性好。频率选择表面设计对制备耐高温宽频吸波涂层具有重要的指导意义。     

Fracture mechanics analysis of delamination buckling of a porous ceramic foam coating from elastic substrates

Ceramic foams are ideal materials for thermal protection systems such as those used as a thermal shield on the space shuttle. The working temperature difference between the outer and inner surfaces of the ceramic foam is extremely high. Under this adverse condition, the ceramic foam coating could buckle from its underneath structures. Therefore, the general problem of damage due to buckling delamination of a ceramic coating on an elastic substrate is investigated in this paper. The delamination buckling amplitude and the stress intensity factor at the tip of buckling region are derived in closed form in terms of the porosity of the ceramic foam. Based on the maximum amplitude and the critical stress intensity factor criteria, critical temperatures of coating buckling from the substrate are established. A fitting formula of maximum buckling amplitude as a function of outer surface temperature is given. It is found that higher porosity and length-to-thickness ratio of the coating will result in a smaller stress intensity factor. However, it seems that the buckling amplitude is independent of the porosity of ceramic foams.     

风挡玻璃表面涂层的制备与研究

在众多的涂层材料中,有机无机复合涂层材料在改善有机玻璃表面性能方面表现出独特的优点。本文中选择以透明甲基硅树脂为有机涂层,而后在有机涂层中添加纳米级陶瓷颗粒。固化成膜后,陶瓷纳米颗粒均匀分散在甲基硅树脂分子链中,无机相的存在将明显改善有机基体表面性能,将有机玻璃的耐磨性提高到了无机玻璃的水平。     

Analysis of corrosion protection behavior of Al2O3-TiO2 oxide ceramic coating on carbon steel pipes for petroleum industry

Corrosion is the deterioration of materials by chemical interaction with their environment. In the oil and gas industry, corrosion of the pipelines and other equipment is one of the leading causes of failure and the corrosion-related costs are very high. Hence, corrosion protection is an essential requirement. In this study, the objective is to analysis of the corrosion protection behavior of spray Alumina-Titania (Al₂O₃-TiO₂) oxide ceramic coating on carbon steel pipes C45 using two different thermal spray coatings processes. These two different thermal spraying coating, High velocity oxy-fuel (HVOF) and plasma thermal spraying techniques can be used instead of extensive treatment by expensive chemical formation of coatings on pipelines and equipment to improve or restore a component's surface properties or dimensions and to protect them from corrosion. Molten or semi-molten ceramic composite powders are sprayed on the surface in order to produce a dense coating layer. FESEM of coated samples showed that a high temperature of plasma coating method end in melting the ceramic powders and creation of completely melted regions on the coated samples’ surface compared to HVOF coating techniques. Corrosion testing of coated samples in seawater (3.5% NaCl) was conducted within 30 days. Electrochemical impedance spectroscopy (EIS) as well as potentiodynamic polarization outcomes represented that the corrosion resistivity of plasma coating technique for this type of ceramic composite is better than HVOF coating technique. However, both types of coating techniques are protecting the substrate against seawater.     

钛酸钡基电子陶瓷材料的改性进展

钛酸钡基电子陶瓷材料广泛应用于电容器、集成电路、传感器及热敏电阻等领域。高容量、小型化、抗击穿及低损耗等工业需求对钛酸钡基电子陶瓷材料的性能提出更高的要求,改性则是提高陶瓷材料性能的主要手段。综述了近年来钛酸钡基电子陶瓷材料在掺杂改性、复合改性及物理改性方面的研究进展。分析了钛酸钡基电子陶瓷材料在改性中存在的问题,比如：常规元素掺杂制备参数优化不足、稀土元素掺杂种类偏少、包覆效果待提升、聚合物陶瓷复合体综合性能欠佳、烧结工艺尚待优化等。提出了解决方法,比如：探索多种元素掺杂、优化工艺参数、改进包覆与聚合方式等。指出了钛酸钡基电子陶瓷材料的未来发展方向,即：强化烧结过程中晶粒尺寸、晶体形状、组分调控的机理研究,选取更多稀土元素进行改性,探索包覆掺杂改性、聚合物复合改性等新工艺。     

Investigation of properties of electric arc ion deposited TiN coating on Al2O3-based ceramic composite

Electric arc ion deposition technique was adopted to deposit TiN coating on Al2O3-based ceramic composite. Scanning electron microscopy and secondary ion mass spectrometry were used to analyze the microstructure, phase constitution, and quality of the TiN coating and the interface. Surface roughness and micro-hardness of the TiN coating were measured to evaluate its quality. Flexural strength of ceramic materials is dependent on both their inherent resistance to fracture and the presence of defects, thus it was used to investigate the effect of electric arc ion deposition technique on the surface modification of Al₂O₃-based ceramic composite. Experimental results show that the higher the deposition bias voltage, the better the coating quality. The TiN coating is homogeneous, with a uniform surface, and free of defects when the deposition bias voltage is 300 V. The TiN coating strongly adheres to the Al₂O₃-based ceramic composite, and the observed elemental interface diffusion strengthens the interface bonding.