Acidic magnetorheological finishing of infrared polycrystalline materials

作者：Salzman S^*; Romanofsky H J; West G; Marshall K L; Jacobs S D; Lambropoulos J C

来源：Applied Optics, 2016, 55(30): 8448-8456.

DOI：10.1364/AO.55.008448

Chemical-vapor-deposited (CVD) ZnS is an example of a polycrystalline material that is difficult to polish smoothly via the magnetorheological finishing (MRF) technique. When MRF-polished, the internal infrastructure of the material tends to manifest on the surface as millimeter-sized "pebbles," and the surface roughness observed is considerably high. The fluid's parameters important to developing a magnetorheological (MR) fluid that is capable of polishing CVD ZnS smoothly were previously discussed and presented. These parameters were acidic pH (similar to 4.5) and low viscosity (similar to 47 cP). MRF with such a unique MR fluid was shown to reduce surface artifacts in the form of pebbles; however, surface microroughness was still relatively high because of the absence of a polishing abrasive in the formulation. In this study, we examine the effect of two polishing abrasives-alumina and nanodiamond-on the surface finish of several CVD ZnS substrates, and on other important IR polycrystalline materials that were finished with acidic MR fluids containing these two polishing abrasives. Surface microroughness results obtained were as low as similar to 28 nm peak-to-valley and similar to 6-nm root mean square.

• 出版日期2016-10-20