中译英一篇科技文本需要用词准确表达简明专业术语给我列出来：1引言熔石英玻璃作为典型的宽禁带介质材料广泛应用于制造光栅、真空窗口、屏蔽片和透镜等器件。为了实现高精度熔石英玻璃的批量制造国内外普遍采用磨削成形→精密研磨→超精密抛光的工艺流程。其中抛光加工作为光学材料精密超精密制造工序的最后一个步骤对元件的加工质量和表面完整性有着重要作用。传统的化学机械抛光技术通过化学能和机械能的耦合作用获得光洁平整的

Introduction Fused quartz glass, as a typical wide bandgap dielectric material, is widely used in the manufacturing of gratings, vacuum windows, shielding plates, lenses and other devices. In order to achieve high-precision mass production of fused quartz glass, the process of "grinding shaping -> precision grinding -> ultra-precision polishing" is commonly used both domestically and internationally. Among them, polishing is the last step in the process of precision/ultra-precision manufacturing of optical materials, and has an important role in the processing quality and surface integrity of the components.

Traditional chemical-mechanical polishing technology obtains a smooth and flat surface through the coupling of chemical energy and mechanical energy. However, due to the normal cutting action of abrasive particles during the processing of the workpiece, it is easy to produce mechanical defects such as scratches, microcracks or pits below the surface, and these defects are prone to induce material melting and explosive damage under strong laser irradiation. In recent years, the magnetic-assisted polishing technology, which uses fluid dynamic pressure shearing to remove materials, has received widespread attention from scholars both domestically and abroad, and has gradually developed into a method for processing strong light element surfaces with "near-zero" defects. According to the different magnetic microparticles (micron-sized iron powder or nano-sized ferric oxide) in the polishing liquid, magnetic-assisted polishing technology can mainly be divided into three types: magnetorheological fluid (MRF), magnetic fluid (MF) and magnetic compound fluid (MCF) polishing. Magnetic-assisted polishing uses magnetic microparticles, non-magnetic abrasive particles, cellulose and deionized water to form a viscous semi-solid flexible polishing head. The abrasive particles under the polishing head come into contact, move relative to the workpiece, and achieve low-damage, high-precision polishing through micro-cutting action.

Shi et al. analyzed the feasibility of elastic MRF polishing based on elastic-plastic deformation theory, and achieved chemical dominant elastic MRF polishing of large-diameter fused quartz glass by changing the composition of magnetorheological fluid and polishing parameters, ultimately obtaining an ultra-smooth surface with a roughness Ra of 0.167 nm. Jiang et al. compared the differences in normal polishing force, tangential polishing force, material removal rate and surface roughness of the workpiece during traditional MCF polishing and ultrasound-assisted MCF polishing processes, and the results showed that ultrasound-assisted polishing was conducive to improving the material removal rate and surface smoothness of the workpiece. Guo et al. showed that the material removal rate of BK7 glass during end-face MCF polishing was positively correlated with the speed of the liquid-bearing disk, negatively correlated with the polishing clearance, and established a material removal rate model related to tangential and normal forces of the workpiece. The above research has studied the material removal mechanism and surface quality formation mechanism of magnetic-assisted polishing technology from both theoretical and experimental aspects, and has promoted the application of magnetic-assisted processing technology in the field of optical manufacturing.

This article uses magnetic polishing liquid with different polishing clearances and different iron powder volume ratios to carry out magnetic-assisted polishing of fused quartz components for different periods of time, and analyzes and evaluates the material removal rate, surface roughness, and transmittance of fused quartz. Combined with simulation calculations of spatial magnetic induction strength, the influence of spatial magnetic induction strength and iron powder volume ratio on material removal efficiency and surface quality is clarified, and a polishing process of "small polishing clearance + high iron powder ratio polishing liquid -> large polishing clearance + low iron powder ratio polishing liquid" is proposed, providing theoretical basis and technical support for the efficient and low-defect processing of strong laser components.

2 Experiment 2.1 Sample preparation In this experiment, magnetic-assisted polishing was performed on fused quartz glass components using a self-built circular polishing machine. The polishing equipment is shown in Figure 1. The horizontal spindle drives a ring-shaped neodymium-iron-boron (Nd-Fe-B) magnet with a magnetic flux density of 0.4 T to rotate at a speed of nt, forming a dynamic spatial magnetic field. A ring-shaped polylactic acid (PLA) baffle plate with the same outer diameter of 40 mm and inner diameter of 25 mm and a thickness of 4 mm is installed on both ends of the magnet to form a polishing wheel. The polishing clearance δ exists between the polishing wheel and the workpiece below it. The fused quartz glass with a size of 40mm×40mm×5mm was used as the processing object. The workpiece was polished on both sides with W5-W10 silicon carbide before polishing, and the initial surface roughness Ra was 0.2-0.25 μm, with sub-surface crack depth within 4.5 μm