为深入理解抛光过程中抛光垫纤维结构、抛光液与工件间的相互作用机制, 该文构建了一种流-固耦合分析框架。通过综合实验验证与数值建模两大路径, 系统评估了有序平纹和无序非织造布抛光垫在抛光效能上的差异。针对熔融石英材料的超精密加工需求, 特制了一种绿色环保的抛光液, 其配方融合了氧化铈磨料、过氧化氢及瓜尔胶成分, 并在不同纹理的抛光垫(平纹与非织造布)上进行了应用测试。实验结果显示, 采用非织造布抛光垫的抛光后表面粗糙度Sa低至0.181 nm, 显著优于平纹抛光垫的0.486 nm; 同时, 前者导致的亚表面损伤层厚度也大幅减少至4.14 nm, 仅为后者的1/3(约12.12 nm)。进一步, 流-固耦合模型分析揭示, 非织造抛光垫在抛光过程中展现出更为均匀的纤维应力分布, 最大应力值仅约0.5 MPa, 远低于平纹抛光垫的6 MPa; 此外, 抛光液中的应力分布也趋于均匀, 这一特性优化了整体抛光系统内应力的传递与扩散效率, 促进了材料的均匀去除。综上所述, 本文不仅从实验与数值双重维度凸显了无序非织造抛光系统在熔融石英超精密加工领域的优越性, 更为纤维集合体抛光垫、抛光液与工件间复杂抛光系统的分析、设计乃至制造实践开辟了新的思路与方法。

Objective: Chemical mechanical polishing (CMP) is an ultra-precision machining technology for hard and brittle materials. The technology has garnered significant attention from researchers worldwide owing to its low cost of processing equipment and relatively simple operational process. In the CMP process, the polishing pad plays a critical role. It not only serves as the medium for storing the polishing slurry and abrasive particles but also transfers the processing load. This paper presents a fluid-structure coupling analysis framework to elucidate the fiber structure of the polishing pad and the interaction mechanism between the polishing slurry and the workpiece during the polishing process. Methods: An innovative fluid-structure coupling analysis framework is proposed to investigate the interaction mechanism between the fiber structure of the polishing pad, the slurry, and the workpiece during the polishing process. Through comprehensive experimental verification and numerical modeling, the polishing efficiency differences between the ordered plain weave polishing pad and the disordered nonwoven polishing pad were systematically evaluated. To meet the ultra-precision processing requirements of fused silica materials, a green and environmentally friendly polishing slurry was specially developed. The slurry consisted of cerium oxide abrasive, hydrogen peroxide, guar gum, and deionized water. The composition of the polishing slurry and the polishing process were optimized through a single-factor test. Subsequent experiments were conducted on polishing pads with different textures (ordered plain weave fabric and disordered nonwovens) using the optimized slurry and process. The experimental procedure was further optimized through a single-factor test. Results: The experimental results showed that the surface roughness (Sa) of the nonwoven polishing pad was as low as 0.181 nm, which was significantly better than that of the plain weave pad (0.486 nm). In addition, the thickness of the subsurface damage layer caused by the nonwoven pad was reduced to 4.14 nm, approximately one-third of that of the plain weave pad (about 12.12 nm). A comparison of the surface elements of fused silica before and after polishing revealed that the polished sample had no impurity residue on the surface after cleaning. The difference in fiber structure between the two polishing pads only affected mechanical removal during the polishing process but did not influence the chemical reaction. Furthermore, the fluid-structure coupling model analysis revealed that the nonwoven polishing pad exhibited a more uniform fiber stress distribution during polishing, with the maximum stress value being only about 0.5 MPa, considerably lower than the 6 MPa observed for the plain weave pad. In addition, the stress distribution of the slurry in the system was more random and uniform, which optimized the stress transfer and diffusion efficiency throughout the overall polishing system and promoted uniform material removal. Conclusions: In conclusion, this paper highlights the advantages of the disordered nonwoven polishing system in the precision processing of fused silica from both experimental and numerical perspectives. It also provides valuable insights for the analysis, design, and manufacturing practices of complex polishing systems involving fiber aggregate polishing pads, slurry, and workpieces.