NFZ System (NANO-FEMTO-ZETA-RC)
Complete automated grinding and polishing workflow with precise control for polishing pads and final finishing steps.
Key Considerations
Choose the Right Texture
Use low-napped pads for rough polishing with diamond abrasives. High-napped cloths are ideal for final polishing with fine abrasives.
Match with Suspensions
Pair pads with appropriate abrasives: diamond for rough stages, alumina or colloidal silica for final polishing.
Select Proper Backing
Choose PSA (adhesive) or magnetic backing based on your platen system. Both provide secure attachment for consistent results.
Introduction
Selecting the right polishing pad is essential for achieving precise, repeatable surface finishes. Pads vary in nap height, backing type, and material composition, which impacts abrasive support, flatness, and edge retention.
Rough polishing: Use low-napped pads with diamond abrasives to remove grinding damage.
Final polishing: Use high-napped cloths with fine abrasives (alumina or colloidal silica) to eliminate minor defects and achieve mirror finishes.
Choosing the correct pad minimizes artifacts such as edge rounding, relief, and smear, ensuring accurate microstructural analysis.
Backing options: Pads are available with PSA (adhesive) or magnetic backing. Magnetic-backed pads simplify pad transitions and are ideal for high-throughput applications.
Pad Selection Guideline
Select the appropriate pad based on polishing stage and material requirements:
| Pad Image & Link | Use Case | Pad Icon | Polishing Stage |
|---|---|---|---|
|
CERMESH metal mesh pad used for semi-fixed abrasive coarse to intermediate lapping. Excellent for initial removal of damage from sectioning and hard materials. |
|
Coarse / Intermediate |
|
POLYPAD is a durable synthetic polyester pad ideal for intermediate polishing, especially with 6-15 µm diamond abrasives. Designed as a long-life nylon alternative. |
|
Intermediate |
|
TEXPAN is a widely used non-woven intermediate polishing pad, compatible with most diamond suspensions. Effective across a broad range of materials. |
|
Intermediate |
|
Black CHEM 2 is a porometric polymer pad with rubber-like consistency, offering balanced action between low and high nap pads. Ideal for moderate nap intermediate polishing. |
|
Intermediate |
|
DACRON II is a low-napped soft polishing pad widely used in Europe for intermediate steps on metals. Suitable for 1-15 µm diamond abrasives. |
|
Intermediate |
|
NYPAD is a low-napped silk pad tailored for intermediate polishing of harder metals and alloys. Performs well with mid-size diamond abrasives. |
|
Intermediate |
|
GOLD PAD is a low-napped pad ideal for 1-9 µm polishing. Designed for consistent material removal and flatness control during final pre-polishing. |
|
Intermediate |
|
ATLANTIS is a woven low-nap final polishing pad with foam backing for enhanced compliance. Ideal for 1-6 µm diamond. Great for critical surface flatness needs. |
|
Final |
|
MICROPAD is a high-napped final polishing pad ideal for producing a mirror finish on metals and polymers. Recommended for <1 µm diamond or colloidal silica. |
|
Final |
|
TRICOTE is a tight high-napped final polishing pad for metals. Offers better control of surface texture and minimal abrasive drag. |
|
Final |
|
NAPPAD is a very high-napped final polishing pad tailored for soft metals and polymers. Provides gentle polishing action to minimize pull-out and relief. |
|
Final |
|
MOLTEC 2 is a wool-based final polishing cloth used when edge retention is not critical. Works well with alumina and colloidal silica on metals. |
|
Final |
|
FELT PAD is a thick final polishing pad made for large samples or glass. Ideal for use with colloidal silica or alumina slurries where surface uniformity is key. |
|
Final |
Process Description
Polishing involves two stages: rough and final. Rough polishing removes deformation from grinding using low-napped pads and polycrystalline diamond abrasives. Final polishing uses high-napped cloths and finer abrasives (alumina or colloidal silica) to eliminate minor defects.
Minimize polishing time to prevent artifacts like relief, edge rounding, and smear. Excessive polishing can compromise microstructural accuracy. For detailed polishing techniques and best practices, see our Polishing Methods Guide.
Minimizing Polishing Artifacts
- Minimize sectioning and grinding damage upfront
- Use the finest effective abrasive at each stage
- Ensure polishing plates are flat (≤2.5 µm runout for 8" plates)
A flat plate prevents uneven pressure that leads to polishing relief. Lap plates to within these tolerances for best results.
Recommended Procedures
- Place pad on a flat lap plate
- Pre-charge pad with abrasive suspension, paste, or powder
- Apply appropriate lubricant
- Begin polishing with reduced force to avoid tearing
- Clean specimen and pad during the last 10-15 seconds
- Clean and dry specimens thoroughly
Troubleshooting
| Symptom | Cause | Solution |
|---|---|---|
| Coarse Scratching | Contamination on polishing pad | Replace pad with a new one |
| Tearing of Pad | Excessive force or poor lubrication | Reduce force and improve lubrication frequency |
| Excessive Relief / Edge Rounding | Improper pad selection or prolonged polishing | Use appropriate pad; shorten polishing time and reevaluate prior steps |
Related Equipment
GIGA-S Vibratory Polisher
High-capacity vibratory polishing system for batch processing and final polishing of metallographic samples.
Frequently Asked Questions
Common questions about polishing pads and cloths
What type of polishing pad should I use for my material?
Pad selection depends on your material and polishing stage. For rough polishing of hard materials, use low-napped pads with diamond abrasives. For final polishing, use high-napped cloths with fine alumina or colloidal silica. Softer materials may require medium-napped pads to balance material removal and edge retention. Consult our pad selection guide above for material-specific recommendations.
Should I use PSA or magnetic-backed pads?
PSA (pressure-sensitive adhesive) pads stick directly to any flat surface and are cost-effective for dedicated applications. Magnetic-backed pads offer quick pad changes and are ideal for high-throughput labs or when frequently switching between polishing steps. Both provide secure attachment and consistent results when properly applied.
How long do polishing pads last?
Pad life depends on material type, abrasive used, polishing pressure, and maintenance. Rough polishing pads typically last 50-200 samples, while final polishing cloths may last 100-500 samples with proper care. Replace pads when they become contaminated, torn, or lose their nap texture. Regular cleaning and proper storage extend pad life significantly.
What polishing pressure and speed should I use?
For rough polishing, use moderate pressure (20-30 N) at 150-300 RPM. For final polishing, reduce pressure (5-15 N) and speed (100-150 RPM) to minimize deformation and achieve mirror finishes. Automated systems typically use counter-rotation with platen speeds 50-100 RPM higher than head speed. Always start with manufacturer recommendations and adjust based on results.
How do I achieve the best surface finish?
Achieving optimal surface finish requires proper pad selection, adequate abrasive suspension, appropriate pressure and speed, and thorough cleaning between steps. Always progress through finer abrasive sizes systematically. Remove all grinding damage before moving to finer polishing steps. Use fresh, uncontaminated pads and suspensions. Clean specimens thoroughly between each step to prevent cross-contamination.
What should I do if I'm getting scratches during polishing?
Scratches during polishing typically indicate contamination from previous steps. Replace the polishing pad with a fresh one dedicated to that abrasive size. Ensure specimens are thoroughly cleaned between steps. Check that your abrasive suspension is not contaminated. Reduce polishing pressure and verify you've removed all damage from previous grinding steps. Never reuse polishing pads across different abrasive sizes.