Brown corundum can indeed be used in wear-resistant coatings. Its high hardness and excellent wear resistance make it an ideal reinforcement material. The following is a detailed analysis and application suggestions:
1. Characteristics and advantages of brown corundum
High hardness (Mohs 9): can significantly improve the wear resistance of the coating and is suitable for high friction environments.
Chemical inertness: acid and alkali resistant, corrosion resistant, suitable for harsh environments such as chemical and marine.
Thermal stability: can withstand high temperatures (about 1800℃), suitable for high temperature conditions.
Controllable particle morphology: different particle sizes (micrometer to millimeter level) can be obtained by crushing and grading to meet the requirements of coating thickness and surface smoothness.
2. Application in wear-resistant coatings
As a functional filler: the addition amount is 20%-40% (weight ratio), directly mixed into the resin matrix (such as epoxy, polyurethane).
Surface modification: Use silane coupling agent or titanate to treat the particle surface to enhance the interfacial bonding with the resin and prevent shedding.
Gradient coating design: compounded with silicon carbide, ceramic microspheres, etc. to form a multi-layer structure to optimize the overall wear resistance and impact resistance.
3. Typical application scenarios
Industrial floor: areas such as warehouses and workshops that are frequently subject to mechanical wear.
Mining machinery: inner wall protection of crushers and conveying pipelines.
Shipbuilding and marine engineering: corrosion-resistant and wear-resistant coatings for decks and hulls.
Aerospace: high-temperature wear protection for engine components.
4. Precautions and optimization suggestions
Particle size matching: coarse particles (80-120 mesh) are used for thick coatings to resist impact, and fine particles (above 325 mesh) are used for thin coatings to smooth the surface.
Dispersion process: use high-speed shearing equipment or three-roll mills to avoid agglomeration; add dispersants (such as BYK series) to improve uniformity.
Cost control: if there is no requirement for color, uncalcined brown corundum can be used (lower cost), but it is necessary to verify whether its purity meets the standard.
Environmental compliance: Ensure that the raw materials comply with RoHS and REACH standards, and avoid excessive heavy metals (such as Fe and Ti).
5. Comparison of alternative solutions
Silicon carbide: Higher hardness (Mohs 9.5), but higher cost, brittle, suitable for extreme wear environments.
Zirconium oxide: Good toughness, but high density, which may cause coating sedimentation.
Composite solution: Brown corundum + graphite (10%) can reduce the friction coefficient and is suitable for sliding friction scenarios.
6. Verification and testing recommendations
Laboratory testing: Evaluate wear resistance according to ASTM D4060 (Taber wear) and ASTM D968 (falling sand method).
Field test: Apply paint on a small area of the target equipment and track the actual wear for 6-12 months.
Conclusion
Brown corundum is a cost-effective choice for wear-resistant coatings, especially for scenarios with medium to high wear and cost and performance. The coating life can be further improved by optimizing particle grading, surface modification and compounding with other materials. It is recommended to conduct a small test first and adjust the formula according to the specific working conditions.