For coated sapphire components used in optical and precision applications, metallographic cross-sectioning is often used to evaluate coating and ink-layer thickness, interface quality, and overall integrity.

The challenge is preparation.
Thin coatings can easily suffer from edge chipping, delamination, pull-off, or rounding during cutting and polishing, making the final cross-section difficult to measure accurately.

For this sample, we used precision low-speed sectioning and cold mounting to minimize mechanical and thermal damage, followed by a gradual grinding and polishing process:

• DiaRe P400 diamond grinding disc for initial grinding

• POS fine grinding disc + 9 μm PD-WT polycrystalline diamond suspension

• SC white silk polishing cloth + 3 μm PD-WT polycrystalline diamond suspension

• SC white silk polishing cloth + 1 μm PD-WT polycrystalline diamond suspension for fine polishing

For coated samples like this, a good surface is not enough — preserving the true coating edge is what makes thickness measurement reliable.

#Metallography #Sapphire #CoatingAnalysis #CrossSection #SamplePreparation #OpticalMaterials