【作者】 华勇；

【导师】 蒋登高；

【作者基本信息】 郑州大学 ， 化学工艺， 2006， 博士

【摘要】 碳化硅(SiC)微粉作为磨料或填料在陶瓷精磨磨具、树脂抛光砂轮以及金刚石抛光砂轮等方面有着广泛的应用。由于它的优异性能如硬度高，强度高，抗氧化和耐磨性能十分突出等，SiC微粉在耐火材料、工程陶瓷、结构材料等非磨削用途方面的应用也非常广泛。目前，SiC已经成为发展现代国防、现代工业和高新科技的主要原材料。 由于细粒度(10μm以细)的SiC微粉表面能较大、易团聚，不仅在陶瓷磨具的浇注成型工艺中分散性和流动性达不到成型工艺性能要求，而且在树脂抛光砂轮生产中与结合剂的相容性也较差，因此，易造成磨具的强度低、过早脱砂，抛光质量和耐用度等使用性能达不到要求，严重影响了磨具制品的质量。显然，本课题的技术关键及难点在于制备分散稳定且固相含量较高、黏度较低的SiC浆料，以解决陶瓷磨具成型工艺性能；改善SiC微粉的分散性以及与树脂结合剂的相容性，以提高树脂磨具的使用性能。 本文选择粒度号为F1200，粒径分布较窄(0.6～14μm)的SiC微粉作为研究对象，根据胶体的分散稳定原理，针对陶瓷和树脂磨具在制备过程中存在的问题，分别设计了SiC微粉的表面改性方法。 一、针对陶瓷磨具在浇注成型工艺中存在的问题，提出了采用疏水预处理和接枝聚合的方法对SiC微粉进行表面改性，制备出了在水基体系中分散稳定的改性SiC悬浮浆料，改善了陶瓷结合剂磨具水浇注成型工艺性能。 1．通过硅烷偶联剂疏水预处理和丙烯酰胺在其表面接枝聚合改性，获得了有机包覆的改性SiC微粉。研究了影响SiC微粉表面改性的各种因素，并优化出较佳的工艺条件。 2．通过对比表面积、润湿性、堆积密度和粒度分布等测试手段讨论了改性SiC粉体的性能，并采用红外光谱(IR)、X-ray衍射等测试技术分析了改性前后SiC微粉表面物质的化学组成和结构特征。 3．实验研究了改性前后SiC微粉的分散稳定性和流动性。以zeta电位的测试更多还原

【Abstract】 Silicon carbide (SiC) powder, as the abrasive material or the stuffing, has the extensive application in vitrified bonded abrasive product, resin bonded polishing wheel and in diamond polishing wheel. Because of its outstanding characteristics, such as high hardness, high strength, the oxidization resistance and wear-resistance, SiC powder also has been used extensively in refractories, engineering ceramics and configuration material etc.. SiC now has become the main material in the modern national defense, modern industry and new science and technology.Because of the high surface energy and easy reunion of the ultrafine SiC powder (<10 μm), neither can the dispersibility and fluidity reach the request of casting process in the vitrified abrasive product, nor can the compatibility difference with resin bond be suited in the polishing wheel. So, the abrasive products have the problems of low strength and easy wearing off. The polishing quality and life periods cannot satisfy the users. Obviously, the key points are how to prepare the dispersed, stable and low viscosity SiC concentrated slurry in order to improve the capacity of the casting process in vitrified abrasive product; and how to prepare the dispersed and compatible SiC powder in order to enhance the application capacity of resinoid abrasive polishing wheel.In this topic, F1200 SiC powder (0.6~ 14μm) was chosen as the study object and two methods of surface modification on its surface were designed according to the basic mechanism of dispersion and stability.1. Aiming at the problems existing in the casting process, we designed a method of surface modification of graft polymerization on SiC powder surface. The modified SiC powder could be dispersed in aqueous media, and the performance of SiC slurry in casting forming was improved in manufacturing vitrified abrasive product.1). The surface modified SiC fine powder was prepared by organic coating through silane coupling agent hydrophobic processing and acrylamide monomer graft polymerization on its surface. Various influencing factors of the surface modification were researched, and the optimal craft condition was ascertained after the orthogonal更多还原