Application · Metallography
Colloidal silica for metallographic final polishing
High-purity colloidal silica of 27 to 74 nm for deformation-free final polishing and EBSD preparation. Supplied in bulk to consumables brands and distributors that make their own polishing suspensions.
Why colloidal silica
The last step before the microscope
Colloidal silica is the standard abrasive for the final polishing step in metallographic sample preparation. Its fine, spherical particles and alkaline pH combine mild chemical attack with very light mechanical action, so the surface is polished rather than scratched.
- Removes the fine scratches and thin deformed layer left by diamond polishing
- Gives a flat, deformation-free surface for optical microscopy and EBSD
- Works well on soft and ductile metals that smear easily, such as aluminum, copper and titanium alloys
- Also used on steels, nickel alloys, ceramics and semiconductor cross-sections
Recommended grades
Grades for final polishing suspensions
Typical final polishing suspensions use particles of about 0.02 to 0.06 µm. CS-HP 41K fits this range directly; CS-HP 74K is slightly coarser and suits hard materials where faster removal is wanted.
| Grade | Particle size (DLS) | SiO₂ | pH | Stabilizer | Best for |
|---|---|---|---|---|---|
| CS-HP 41K | 41 nm | ≈40% | 9–11 | Potassium | Final polishing of metals, EBSD preparation, optical glass |
| CS-HP 27K | 27 nm | ≈40% | 9–11 | Potassium | Very fine finish on soft metals and glass |
| CS-HP 74K | 74 nm | ≈41% | 9–11 | Potassium | Faster final polishing of hard metals and ceramics |
Particle size and SiO₂ are typical values from production batches; pH is the specification range. Full TDS, SDS and trace-metal data on request.
For consumables brands
Supply for your own polishing suspension
Concentrate in bulk
We supply the colloidal silica concentrate in 25 kg drums or IBC totes. You dilute, add your own additives and bottle under your brand.
Private label
Neutral packaging and labels on request. Your formulation and customer details are kept confidential.
Consistent batches
Every batch comes with a COA for particle size, SiO₂, pH and density. Trace-metal reports are available on request.
Tailored grades
Need a different particle size, solids content or pH? We adjust the grade to match the product you sell today.
FAQ
Common questions
What particle size is used for metallographic final polishing?
Most final polishing suspensions use colloidal silica of about 0.02 to 0.06 µm (20 to 60 nm). Our CS-HP 41K, at 41 nm, sits in the middle of this range.
Can I dilute the concentrate?
Yes. CS-HP grades are supplied at about 40% SiO₂. Polishing suspensions are usually diluted with deionized water before use; the right ratio depends on your material and polishing cloth.
How do I stop colloidal silica from drying on the cloth?
Colloidal silica can crystallize when it dries. Rinse the cloth with water at the end of each run, keep the container closed, and do not let the suspension freeze. Some brands also add anti-crystallization additives to their suspensions.
Do you supply ready-to-use bottles?
We mainly supply the concentrate in drums for brands and distributors that bottle under their own label. Ask us if you need diluted product or smaller packs.
Test it on your own samples
Tell us your material, current polishing product and target finish. We will suggest a grade and send a free sample with its COA. Freight is paid by the customer, by courier account or in advance.
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