In the realm of optical glass manufacturing, the quest for precision and efficiency is unending. A recent breakthrough by Quanxin Zhang, a researcher at Gansu Rare Earth New Material Limited-Liability Company, has brought the industry one step closer to achieving unparalleled polishing performance. Zhang’s work, published in ‘Jin’gangshi yu moliao moju gongcheng’ (translated to ‘Rare Earths and Polishing Materials Engineering’), introduces a novel LaCePr rare earth polishing slurry that promises to revolutionize the chemical mechanical polishing (CMP) process for optical glass.
The study delves into the intricate process of preparing a LaCePr rare earth polishing slurry using Baotou mixed rare earth ore as the primary raw material. The process involves a series of complex steps, including concentrated sulfuric acid enhanced roasting, water leaching, neutralization, impurity removal, and P507 extraction transformation and grading. The resulting slurry is then subjected to a series of treatments, including co-flow precipitation, fluorination, high-temperature roasting, introduction of additives, slurry mixing, and wet ball milling. The meticulous preparation ensures that the final product is not only effective but also environmentally friendly, achieving zero wastewater discharge.
Zhang’s research reveals that the microstructure of the solid polishing powder in the LaCePr slurry consists of irregular polygonal spherical grains tightly aggregated, with no coarse particles present. This uniformity is a testament to the positive effects of introducing fluorine (F) and doping with praseodymium (Pr) on the lattice distortion of cerium dioxide (CeO2). The elemental distribution analysis further confirms that the doped lanthanum (La) and Pr elements mainly enter the CeO2 lattice in a solid-solution manner, enhancing the overall polishing performance.
The polishing abilities of the LaCePr slurry were tested extensively. The initial polishing ability of the LaCePr rare earth polishing solution is 203.4 nm/min. After polishing for 40, 60, 80, and 120 minutes, the polishing abilities of the LaCePr polishing solution are 219.7, 214.7, 206.3 and 189.8 nm/min, respectively. This is a significant improvement over the traditional LaCe polishing solution, which showed a maximum polishing rate of 199.9 nm/min after 120 minutes of cumulative polishing.
Zhang emphasizes the commercial impact of this research, stating, “The comprehensive properties of the prepared LaCePr CMP polishing liquid are better. This breakthrough not only enhances the polishing efficiency but also ensures a more sustainable and environmentally friendly process.” The surface roughness of the glass after polishing with the LaCePr slurry is comparable to that of the LaCe slurry, with a surface roughness Sa of 0.668 nm after five CMP cycles.
The implications of this research are far-reaching. For the energy sector, where precision optical components are crucial for solar panels, lasers, and other high-tech applications, this advancement could lead to more efficient and cost-effective manufacturing processes. The ability to achieve higher polishing rates without compromising surface quality opens up new possibilities for the production of high-precision optical components.
As the industry continues to evolve, Zhang’s work sets a new benchmark for CMP technologies. The successful preparation of the LaCePr rare earth polishing slurry, as detailed in ‘Jin’gangshi yu moliao moju gongcheng’, marks a significant milestone in the pursuit of excellence in optical glass manufacturing. This research not only enhances our understanding of the underlying mechanisms but also paves the way for future innovations in the field.
