【摘要】： 磁力研磨加工技術是一種很有前途的光整加工新工藝,具有設計成本低、加工效率高、操作容易、環(huán)境污染低、能源消耗少、容易自動化等優(yōu)點,因此,磁力研磨加工技術不斷獲得發(fā)展,并在生產中得到廣泛應用。而作為該技術磨具的磁性磨料是磁力研磨加工的關鍵所在,為此,本文分析了磁性磨料磨粒的磨削機理,并在此基礎上提出了磁力研磨加工對磁性磨料性能的要求。在對研磨壓力的形成、磁性磨料的組成成分、結構形狀及磁性磨料的制備方法分析研究的基礎上,提出了常壓固相燒結制備磁性磨料的方法。 在傳統(tǒng)燒結法的基礎上,我們采用高溫無機粘結劑替代鈦、鉬等貴重金屬粘結組分,并通過溶膠-凝膠法在鐵粉表面包覆SiO2,在無氣氛保護的常壓燒結電爐中制備了一系列磁性磨料。研究了燒結溫度、燒結時間、壓制壓力、原料配比、鐵磁相種類、磨粒相粒徑和燒結氣氛對磁性磨料性能的影響,確定了最終的實驗參數(shù),并在此條件下制備了一系列磁性磨料。采用熱場發(fā)射掃描電子顯微鏡(SEM)和X射線能量色散譜(EDS)表征了磁性磨料的形貌和元素組成,采用X-射線衍射儀(XRD)研究了磁性磨料的物相組成,并通過實驗對磁性磨料進行了研磨性能測試和耐用度分析。實驗結果表明,燒結法制備的磁性磨料主要由α-Fe、Al2O3、Fe2O3、AlFeO3等相組成,其形狀多為不規(guī)則的棱狀結構；磁性磨料具有良好的研磨效果和較長的使用時間,研磨工件的表面粗糙度可達到0.12μm,使用時間可達24 min以上。 另外,我們以硅鐵粉、白剛玉及耐高溫無機粘結劑為原料進行了探索實驗,研究了燒結溫度、燒結時間和壓制壓力對磁性磨料結合度的影響,采用金相顯微鏡、掃描電子顯微鏡和X射線能量色散儀表征了磁性磨料的形貌和元素組成。實驗結果表明,燒結溫度、燒結時間及壓制壓力與燒結之后磁性磨料的結合度都有密切的關系。燒結溫度越高、燒結時間越長,磁性磨料的結合狀況越好,燒結溫度不要低于1200℃,燒結時間不要低于5 h,以保證剛玉粉與鐵硅粉之間得到良好的結合狀態(tài)；壓制壓力有助于硅鐵粉與剛玉粉之間的結合狀況,成型壓制壓力越大,結合狀況越好。
[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 偽 -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，

本文編號：2153910