烧结法制备磁性磨料

发布时间：2018-07-29 20:25

【摘要】： 磁力研磨加工技术是一种很有前途的光整加工新工艺,具有设计成本低、加工效率高、操作容易、环境污染低、能源消耗少、容易自动化等优点,因此,磁力研磨加工技术不断获得发展,并在生产中得到广泛应用。而作为该技术磨具的磁性磨料是磁力研磨加工的关键所在,为此,本文分析了磁性磨料磨粒的磨削机理,并在此基础上提出了磁力研磨加工对磁性磨料性能的要求。在对研磨压力的形成、磁性磨料的组成成分、结构形状及磁性磨料的制备方法分析研究的基础上,提出了常压固相烧结制备磁性磨料的方法。 在传统烧结法的基础上,我们采用高温无机粘结剂替代钛、钼等贵重金属粘结组分,并通过溶胶-凝胶法在铁粉表面包覆SiO2,在无气氛保护的常压烧结电炉中制备了一系列磁性磨料。研究了烧结温度、烧结时间、压制压力、原料配比、铁磁相种类、磨粒相粒径和烧结气氛对磁性磨料性能的影响,确定了最终的实验参数,并在此条件下制备了一系列磁性磨料。采用热场发射扫描电子显微镜(SEM)和X射线能量色散谱(EDS)表征了磁性磨料的形貌和元素组成,采用X-射线衍射仪(XRD)研究了磁性磨料的物相组成,并通过实验对磁性磨料进行了研磨性能测试和耐用度分析。实验结果表明,烧结法制备的磁性磨料主要由α-Fe、Al2O3、Fe2O3、AlFeO3等相组成,其形状多为不规则的棱状结构；磁性磨料具有良好的研磨效果和较长的使用时间,研磨工件的表面粗糙度可达到0.12μm,使用时间可达24 min以上。 另外,我们以硅铁粉、白刚玉及耐高温无机粘结剂为原料进行了探索实验,研究了烧结温度、烧结时间和压制压力对磁性磨料结合度的影响,采用金相显微镜、扫描电子显微镜和X射线能量色散仪表征了磁性磨料的形貌和元素组成。实验结果表明,烧结温度、烧结时间及压制压力与烧结之后磁性磨料的结合度都有密切的关系。烧结温度越高、烧结时间越长,磁性磨料的结合状况越好,烧结温度不要低于1200℃,烧结时间不要低于5 h,以保证刚玉粉与铁硅粉之间得到良好的结合状态；压制压力有助于硅铁粉与刚玉粉之间的结合状况,成型压制压力越大,结合状况越好。
[Abstract]:Magnetic abrasive machining is a promising new finishing technology, which has the advantages of low design cost, high processing efficiency, easy operation, low environmental pollution, less energy consumption and easy automation. Magnetic abrasive processing technology has been developed and widely used in production. The magnetic abrasive is the key of magnetic abrasive processing. Therefore, this paper analyzes the grinding mechanism of magnetic abrasive particles, and puts forward the requirements of magnetic abrasive processing on magnetic abrasive properties. Based on the analysis of the formation of grinding pressure, the composition of magnetic abrasive, the shape of structure and the preparation method of magnetic abrasive, a method of preparing magnetic abrasive by solid phase sintering under atmospheric pressure was put forward. On the basis of the traditional sintering method, we use high temperature inorganic binder instead of titanium, molybdenum and other precious metal bonding components. A series of magnetic abrasives were prepared by sol-gel method coated with Sio _ 2 on the surface of iron powder in an atmospheres sintered electric furnace without atmosphere protection. The effects of sintering temperature, sintering time, pressing pressure, ratio of raw materials, type of ferromagnetic phase, particle size of abrasive phase and sintering atmosphere on the properties of magnetic abrasive were studied, and the final experimental parameters were determined. A series of magnetic abrasives were prepared under these conditions. The morphology and elemental composition of magnetic abrasive were characterized by thermal field emission scanning electron microscope (SEM) and X-ray energy dispersive spectroscopy (EDS). The phase composition of magnetic abrasive was studied by X-ray diffractometer (XRD). The abrasive properties and durability of magnetic abrasive were tested and analyzed by experiments. The experimental results show that the magnetic abrasive prepared by the sintering method is mainly composed of 伪 -Fe2O3Fe2O3Fe2O3Fe2O3AlFeO3, and its shape is mostly irregular, and the magnetic abrasive has a good grinding effect and a long service time. The surface roughness of the grinding workpiece is 0.12 渭 m and the working time is more than 24 min. In addition, we studied the effects of sintering temperature, sintering time and pressing pressure on the bonding degree of magnetic abrasive with ferrosilicon powder, white corundum and inorganic binder for high temperature resistance. Scanning electron microscope (SEM) and X-ray energy dispersive instrument (EDS) were used to characterize the morphology and elemental composition of magnetic abrasive. The experimental results show that the bonding degree of magnetic abrasive is closely related to sintering temperature, sintering time and pressing pressure. The higher the sintering temperature is, the longer the sintering time is, the better the bonding condition of magnetic abrasive is, the sintered temperature is not lower than 1200 鈩，

本文编号：2153910