Obtaining nanoabrassive for magnetoreological polishing of KDP crystals

Magneto-rheological polishing technology is widely used in the processing of high-precision optical elements. One of the determining factors in magnetorheological polishing technology is the nature and quality of the nanoabrasive in the composition of the magnetorheological suspension. In this study, a method has been developed for the sol-gel synthesis of amorphous silicon dioxide nanospheres used as a nanoabrasive for magnetorheological polishing of water-soluble crystals used for the manufacture of nonlinear optical elements of laser technology. The technical result was achieved by introducing synthesized silicon dioxide nanoabrasive into the composition of the magnetorheological suspension. The physicochemical characteristics of the resulting nanoabrasive are presented. The results of electron microscopy confirm the spherical morphology of SiO2 particles, and a particle size distribution varying in the range of 40–60 nm has been established, which ensures the uniformity and quality of surface treatment of optical elements with a magnetorheological suspension. The structural properties of SiO2 nanoabrasive were studied by X-ray powder diffraction. The introduction of SiO2 nanoabrasive into the magnetorheological suspension made it possible to achieve high quality processing and surface cleanliness, and also ensured final polishing of the surface of KDP single crystals to a roughness value of no more than 6 Å. The results of the work are of interest for optimizing the process and improving the technology of magnetorheological polishing.