Unprecedented developed composite polishing system to achieve atomic surface integrating rough and fine polishing using a novel hyper-conjugated pad through controlling the temperature of a proposed green slurry

Abstract

Efficiency and quality are a pair of everlasting contradictions in manufacturing industry. To achieve atomic surface, it usually consists of rough, precision, and ultra-precision polishing. These processes contain generally several to tens of polishing pads, slurries, and setups, which is time-consuming and expensive. These diverse pads, slurries, and setups are strictly separated, avoiding contamination, damage, and corrosion. To solve these challenges, a novel composite polishing system was developed, using a developed hyper-conjugated polishing pad and custom-made green slurry, through adjusting the temperature of slurry to control the material removal rate (MRR). The MRR was controlled between 40.99 and 133.91 nm/min, by adjusting the temperature between 40 and 80 ℃ via splitting of fibers. After pre-polishing by rare earth cerium oxide abrasive and atomic level polishing by proposed composite system, atomic surface is garnered on fused silica with surface roughness Sa of 0.117 nm at a scanning area of 50 × 50 μm². It is unprecedented that the developed polishing system realized atomic surface integrating rough and fine polishing on a setup by a composite fiber polishing pad and a new green chemical mechanical polishing (CMP) slurry. The CMP slurry included silica, hydrogen peroxide, sodium hydroxy cellulose, and sodium carbonate. Transmission electron spectroscopy confirms that the thickness of damaged layer is 1.89 nm. Prior to and after splitting of fibers, diameter, bending length, and Shore hardness decreased from 18.33 to 2.48 μm, 13.7 to 4.6 cm, and 52.7 to 20.5 HC, respectively, reducing 86.5%, 66.4%, and 61.1% correspondingly. However, wicking height and specific surface area increased from 7.5 to 14.1 cm, and 0.028 to 1.926 m²/g, separately, enhancing 88% and 6779%, accordingly. An interactive model was built among a single fiber, abrasive, and workpiece. After splitting of fibers, the maximum stress exerted on axial and radial directions of fiber are 2.45 and 1.36 MPa, respectively, reducing 59% and 73% compared with those of prior to splitting correspondingly. A model of repeated unit cell was constructed between polishing pad and slurry. It is calculated that the stress of 51.15% units is in the range between 0.1 and 0.5 MPa, while that of 92.83% fibers varies from 0.05 to 1 MPa after splitting. A macroscale model of polishing pad was established. Peak stress of an unsplit pad is high up to 13.19 MPa, while that of split one decreases to 2.42 MPa, reducing 81.65%. At an actual polishing pressure of 30 kPa, contact area of a split polishing pad between fibers and workpiece reaches 15.38%, promoting 44.09% compared with that of an unsplit one. Our developed composite polishing system paves a new way to fabricate atomic surface using a hyper-conjugated polishing pad and a green slurry on a setup, saving several and tens of various pads, slurries, and setups, which are both time and cost-effective and has broad prospects in manufacturing industry.