小口径非球面碳化钨模具的磁场辅助抛光工艺

Magnetic-field-assisted polishing of small aperture aspheric tungsten carbide mould

小口径非球面光学透镜具有优良的光学性能和广阔的应用前景,但其常用的碳化钨模具由于高硬度的材料特性,加工和抛光难度较大.为获得高质量、高精度的小口径非球面透镜,利用磁场辅助的抛光方式对其碳化钨模具进行加工:首先,通过一系列单因素试验选出合适的金刚石微粉粒度和抛光液成分配比,再采用正交试验探究多种工艺参数对抛光效果的影响规律,确定最佳工艺参数组合.结果表明,使用该组工艺参数抛光可以使检测点的粗糙度由10.3 nm降至3.2 nm,刀纹痕迹明显变浅甚至消失.因此,磁场辅助的抛光方式能够有效改善模具表面的波纹度和粗糙度,对于小口径非球面光学元件的加工具有一定的参考意义.

Small aperture aspheric lens secures excellent optical properties and broad application prospects.However,due to the high hardness and other material characteristics,the tungsten carbide mould for preparing small aperture aspheric lens cannot be readily processed and polished,and is commonly used to fabricate small aperture aspheric optical lens.For the purpose of obtaining high-quality and high-precision small aperture aspheric optical lens,its tungsten carbide mould is polished by magnetic-field-assisted polishing method.First,the suitable diamond particle size and composition ratio of polishing liquid are selected through a series of factor experiments.Afterwards,the influence rule of various process parameters on the polishing effect is investigated by orthogonal experiments,and the optimal process parameter combination is determined.Results show that the roughness of the test point can be reduced from 10.3 nm to 3.2 nm by using those process parameters,and the tool marks have conspicuously disappeared.Therefore,the magnetic-field-assisted polishing method can effectively reduce the waviness and roughness of the mould surface,and is significantly regarded for the polishing of small aperture aspheric optical components.