磁性流体研磨加工的实验研究

随着科学技术的发展,电子、光学和军品零件加工精度和表面质量的要求日益提高。采用普通研磨加工方法,虽然加工表面粗糙度和形状精度可符合要求,但表面加工变质层会使零件的机械物理性能降低。为此,开发研究出许多精加工技术。磁性研磨法是70年代新开发研究的一种加工方法,具有高精度、高效率和加工表面无变质层的特点,特别适合难研磨材料和复杂形状表面的研磨加工,并能在研磨加工过程中控制研磨效率和研磨精度。本文以自行研制的研磨装置为实验手段,对磁性流体研磨加工进行工艺试验,探索了研磨时间、磨粒粒径、混合液体积添加率和磁场强度诸因素对研磨效率和研磨精度的影响。并在此基础上对研磨机理进行了初步分析,提出了磁性流体研磨加工中单颗磨粒的运动模型,找出了研磨表面产生铜屑粘连、夹渣、磁性颗粒粘附和较粗划痕等缺陷的原因,以及控制措施。

Experimental Research on Lapping Process Using Magnetic Fluid

With the development of science and technology, the machining precision and the surface quality are becoming increasingly high for many electronic, optical and ordnance parts. Though fine geometrical accuracy such as surface roughness and flatness can be obtained to meet the need by using common lapping method, the detrimental surface layer may reduce the mechanical properties of workpieces. Therefore, many precision processing methods have been turned out. The magnetic floating fluid lapping is a method newly developed in 1970's with high precision, high efficiency and fine surface guality, specially suitable for processing difficult-to-lap materials and workpieces with complicated shape. Furthermore, it is easy to control its polishing efficiency and precision. Based on the technological experiments of lapping which are carried out by use of the device developed by the authors, the effects of the various parameters in the finishing process on its efficiency and precision, such as lapping time, abrasive grain size, fluid concentration and magnetic field strength, are investigated. The lapping mechanism is also Preliminarily analysed and the kinematic model of single abrasive grain in the lappind process is put forward. The occurrence of adhesion of copper microchips, crevice-like defects, embedment of magnetic grain and deep scratches are investigated and some measures for reducing lapping defects are taken.