Polishing slurry is not a simple mixture; it is a complex multiphase dispersion system. Its main functional component-abrasive particles-needs to be uniformly and stably dispersed in the liquid medium to achieve consistent and controllable material removal from the workpiece surface during operation. Once the abrasive particles agglomerate and settle due to factors such as gravity, a series of chain reactions occur:
Performance fluctuations and loss of consistency: Uneven concentration in the upper and lower layers of the polishing slurry means that the cutting ability of the abrasive will change unpredictably at different times or when using different liquid layers. This directly leads to unstable polishing rates, uneven material removal from the workpiece surface, and severely affects batch-to-batch consistency and product yield.
Poor process repeatability: Settling means that the abrasive conditions required for each polishing session vary, making process parameters difficult to fix and optimize, hindering the accumulation and replication of experience, and impeding standardized production.
Equipment wear and product damage: Settled hard particles may accumulate on the polishing pad or at the bottom of the equipment, forming localized hard spots. This not only accelerates uneven wear of the polishing pad but may also cause irreparable scratches, pits, and other defects on the workpiece surface.
Resource waste and increased costs: To prevent sedimentation, frequent stirring or even discarding of some of the settled slurry is often necessary, increasing operational complexity, material consumption, and wastewater treatment costs.
Maintaining long-term, uniform suspension of abrasive particles-that is, excellent suspension stability-is the physical basis for ensuring the long-lasting performance of the polishing slurry, reliable processes, and predictable results.