Diamond Suspension - Polycrystalline

What This Product Is

Polycrystalline diamond suspension is a liquid diamond abrasive used during metallographic polishing to refine specimen surfaces after grinding. It contains polycrystalline diamond particles dispersed in a carrier fluid, allowing controlled material removal during intermediate and fine polishing steps.

Polycrystalline diamond abrasives are characterized by their tendency to fracture during use, which helps maintain consistent cutting action throughout the polishing process.

Intended Use in Metallography

This product is intended for intermediate to fine polishing steps, following planar or fine grinding. It is used to remove residual grinding damage, reduce surface scratches, and prepare samples for final polishing or microscopic examination.

Polycrystalline diamond suspension is commonly selected when:

• Consistent cutting behavior is needed across the polishing step
• Materials exhibit mixed or heterogeneous phases
• Efficient scratch removal is required before final surface refinement

Typical Applications

In metallographic laboratories, polycrystalline diamond suspension is commonly used when polishing:

• Hard metallic alloys
• Carbide-containing materials
• Wear-resistant coatings and hardfaced surfaces
• Materials where uniform abrasion across phases is desirable

Actual polishing results depend on material composition, polishing cloth selection, applied pressure, and cleaning practices between steps.

When This Product Is NOT Ideal

Polycrystalline diamond suspension may not be the best choice when:

• Preparing very soft or highly ductile metals where smearing dominates surface damage
• Extremely fine, deformation-free final surfaces are required with minimal cutting action
• The material responds better to extended polishing with lower aggressiveness

In these situations, alternative abrasives or polishing strategies may be more appropriate.

Where This Fits in the Preparation Process

Polycrystalline diamond suspension is typically used:

• After fine grinding steps or rigid diamond disc grinding
• Before final polishing stages such as colloidal silica or alumina, when required by the application

It is commonly paired with polishing cloths selected based on material hardness and desired surface finish.

Key Characteristics

• Abrasive type: Polycrystalline diamond
• Form: Liquid suspension
• Application: Metallographic polishing
• Use: Manual and automated polishing systems
• Compatibility: Used with appropriate polishing cloths and standard laboratory equipment

Refer to individual product options for available sizes and packaging.

Best-Practice Notes

• Thoroughly clean specimens, cloths, and platens between preparation steps to avoid cross-contamination
• Avoid skipping polishing steps to reduce the risk of persistent scratching
• Use consistent pressure and adequate lubrication during polishing
• Replace polishing cloths when excessive loading or glazing occurs

Frequently Asked Questions

What is the difference between polycrystalline and monocrystalline diamond suspension?

Polycrystalline diamond consists of multiple bonded crystallites that fracture during use, continuously exposing new cutting edges. Monocrystalline diamond maintains a single crystal structure and cuts differently over time.

When is polycrystalline diamond preferred in metallography?

It is commonly preferred when polishing hard or mixed-phase materials where steady, consistent material removal is required.

Can polycrystalline diamond suspension be used for final polishing?

It may be used for fine polishing steps, but some materials benefit from alternative abrasives for final surface refinement.

Does polishing cloth selection matter?

Yes. The polishing cloth strongly influences cutting rate, surface finish, and the overall polishing response of the material.

Is this suspension suitable for automated polishing systems?

Polycrystalline diamond suspensions are commonly used in both manual and automated metallographic preparation systems.