Slurry pH enhancing the material removal rate of fused silica optical glass during chemical mechanical polishing process

Fused silica has been used intensively in many high applications such as astronomy, aerospace, lasers and etc. due to its properties like high transmission in visible, ultra-violet and infrared region, high temperature resistance, hardness, strength, chemical inertness and low linear thermal expansion. For this, ultra-precision machining of fused silica glass is being done by the chemical mechanical polishing (CMP) process, due to the friction generated at the interface of the workpiece-polisher, and due to abrasive slurry chemical reaction and mechanical aggression. In this study, the effect of the abrasive size and the pH value of the slurry have been observed. Result shows that the abrasive slurry with the near neutral pH value, gives the highest value of Material Removal Rate (MRR) for the fused silica optical glass.