Influence of Grinding Parameters on Surface Roughness and Subsurface Crack Damage Depth of Sapphire Crystal

Area of Science:

• Materials Science and Engineering
• Manufacturing Processes
• Surface Metrology

Background:

• Single sapphire crystals are vital in advanced technologies like LEDs, lasers, and optical systems.
• Machining sapphire crystals, particularly grinding, is critical for achieving desired surface quality.
• Understanding grinding parameters is essential for optimizing sapphire crystal performance.

Purpose of the Study:

• To investigate the effects of grinding wheel speed, depth, and feed rate on sapphire crystal surface quality.
• To determine the optimal grinding parameters for minimizing surface roughness (Ra) and subsurface crack damage depth (SSD).
• To develop predictive models for Ra and SSD based on experimental data.

Main Methods:

• A three-factor, five-level orthogonal experimental design was employed.
• Variance and range analysis were used to evaluate the impact of grinding parameters.
• Surface roughness (Ra) and subsurface crack damage depth (SSD) were the primary evaluation indicators.

Main Results:

• Grinding resulted in a mix of brittle and ductile material removal, causing surface pits and subsurface microcracks.
• Grinding wheel speed had the most significant impact on Ra and SSD, followed by feed rate and grinding depth.
• Optimized parameters achieved a surface roughness (Ra) of 0.326 μm and SSD of 2.86 μm.

Conclusions:

• Grinding parameters significantly influence sapphire crystal surface integrity.
• The study provides a basis for improving sapphire crystal grinding processes.
• Achieving full ductile removal requires further optimization beyond the tested parameter range.