Grinding of silicon carbide for optical surface fabrication. Part II. Subsurface damage

Area of Science:

• Materials Science
• Surface Engineering
• Manufacturing Processes

Background:

• Silicon carbide (SiC) grinding generates subsurface damage, impacting material performance.
• Accurate characterization of this damage is crucial for quality control and process optimization.
• Existing methods for subsurface damage assessment can be time-consuming or indirect.

Purpose of the Study:

• To analyze subsurface damage in ground silicon carbide (SiC) using magnetorheological finishing (MRF).
• To evaluate the correlation between MRF spot depth, surface roughness, and subsurface damage.
• To assess the applicability and limitations of MRF for different SiC grades.

Main Methods:

• Grinding of three distinct SiC grades under identical conditions.
• Subsurface damage analysis via magnetorheological finishing (MRF).
• Evaluation of roughness parameters at the base of MRF-induced spots at varying depths.

Main Results:

• Surface roughness parameters decrease with increasing MRF spot depth, reaching a steady-state value.
• The saturation depth correlates with subsurface damage depth, comparable to literature estimates.
• Microstructure significantly influences MRF technique validity; homogeneous microstructures yield reliable results.

Conclusions:

• MRF is a viable technique for estimating subsurface damage depth in SiC.
• The technique's accuracy depends on SiC microstructure homogeneity.
• Porosity or secondary phases in SiC grades can impede conclusive damage assessment via MRF.