Why Do Scratches Occur When Using 600# White Fused Alumina Powder for Polishing Stainless Steel?

1. Uneven Particle Size Distribution and Large Grit Contamination

The typical particle size range for 600# White Fused Alumina Powder is approximately 24–27 μm. If oversized particles (e.g., 40 μm or even 100 μm) are present in the powder, they can cause significant surface scratches.

Common causes include:

-Poor classification resulting in mixed mesh sizes;

-Improper crushing or sieving during production;

-Contaminants such as stones, anti-caking agents, or other foreign materials entering during packing or handling.

2. Skipping Pre-Polishing Steps

The polishing process should follow a stepwise progression from coarse to fine abrasives.

Directly using 600# White Fused Alumina Powder without adequate pre-polishing may fail to remove deeper scratches left from earlier stages, and in some cases, may even amplify surface imperfections.

3. Improper Polishing Parameters

Excessive pressure or rotation speed increases friction between the abrasive and the surface;

This may lead to localized overheating, softening the stainless steel surface and causing thermal scratches or deformation.

4. Inadequate Surface Cleaning Before Polishing

If the surface is not thoroughly cleaned beforehand, residual particles such as metal shavings, dust, or hard contaminants can become embedded in the polishing process, leading to secondary scratches.

5. Incompatibility Between Abrasive and Workpiece Material

White fused alumina has a Mohs hardness of 9, while 304 stainless steel ranges from 5.5 to 6.5;

Sharp-edged or irregularly shaped WFA particles may exert excessive cutting force, resulting in scratch marks;

Improper shape or morphology of abrasive grains can worsen this issue.

6. Low Purity or Poor Quality Powder

If the 600# White Fused Alumina Powder is made from low-grade raw materials, or lacks proper air/water flow classification, it may contain high levels of impurities and irregular particles;

High-purity WFA (≥99% Al₂O₃), with consistent particle size and no oversized grains, is essential for precision polishing.

Purchasing Tips for White Fused Alumina Micro Powder

To reduce the risk of scratching, consider the following tips when sourcing 600# White Fused Alumina Powder:

• Request a detailed particle size distribution report to ensure mesh consistency;

• Choose products with advanced air classification, ensuring fine and uniform particle shape;

• Ensure purity ≥99% Al₂O₃, free from large or hard impurities;

• Buy from suppliers with strict quality control, including SEM, particle analysis, and impurity testing;

• Conduct small-batch compatibility testing with your polishing process and material types;

• Avoid using material from damaged or moisture-exposed packaging to ensure cleanliness and performance.