Lesson 7 – Slurry Fundamentals (Type, APS, Shape, Distribution)

What You Will Learn

• Differentiate common abrasive chemistries (diamond, alumina, ceria, silica)
• Define APS (average particle size) and particle size distribution impacts
• Relate particle shape to removal rate and cosmetic risk
• Select slurry to meet wavefront and cosmetic specifications
• Plan concentration and pH windows before production

Chemistry & APS

Slurries include diamond, alumina, cerium, silica, and others. APS and distribution govern removal and finish: smaller, tighter distributions trend toward smoother finishes at lower removal rates; larger or broader distributions increase removal but can raise scratch risk.

Particle Shape Effects

Shapes influence mechanics and flow. For example, hexagonal shapes can mesh evenly and dull over time, while pill‑like shapes may drive aggressive removal and break down with use. Match shape and friability to your form/cosmetic balance.

Specification Alignment

Map slurry selection to both wavefront (form and mid‑spatial content) and cosmetics (scratch/dig, haze). Validate with trials before committing to production lots.