Polished Alumina Ceramic Square Plates: Key Properties and Industrial Applications

(Polished Al2O3 Ceramic Plate Alumina Square Block)

1. Why Polished Al₂O₃ Ceramic Plate Alumina Square Block Has Excellent Characteristics

1.1 Inherent Material Properties

Polished Al₂O₃ ceramic plates exhibit superior characteristics due to alumina’s intrinsic properties. With high hardness (9 on Mohs scale) and exceptional wear resistance, these blocks withstand abrasive environments better than most metals. Their high-temperature resistance allows operation up to 1,600°C without structural degradation. The polishing process enhances these properties by creating a non-porous surface that minimizes friction and prevents particle adhesion. Additionally, alumina’s excellent electrical insulation and chemical inertness make these blocks suitable for corrosive and high-voltage environments where metals fail.

1.2 Performance Enhancements

The polishing process transforms alumina blocks into precision components with ultra-low surface roughness (Ra ≤ 0.1μm). This mirror finish reduces friction coefficients by up to 80% compared to unpolished ceramics, significantly extending service life in moving assemblies. Precision polishing also achieves exceptional flatness (±0.001mm) critical for semiconductor and optical applications. The surface densification during polishing minimizes micro-cracks that could propagate under stress, enhancing wear resistance and mechanical strength (≥300 MPa). These blocks maintain dimensional stability across extreme temperature fluctuations due to alumina’s low thermal expansion coefficient.

2. What Is Polished Al₂O₃ Ceramic Plate Alumina Square Block

2.1 Composition and Structure

Polished Al₂O₃ ceramic blocks are precision-engineered components composed of ≥95% pure aluminum oxide crystals sintered at >1,600°C. These 95% alumina ceramic blocks feature a dense, polycrystalline structure with grain sizes between 2-5μm. The final polishing stage achieves surface finishes to optical standards (0.1-0.4μm Ra), transforming the matte ceramic surface into a mirror-like plane. Standard dimensions range from 5x5mm to 300x300mm with thicknesses of 1-50mm, though custom geometries are achievable through specialized machining.

2.2 Key Specifications

These technical ceramics meet rigorous industrial specifications: density ≥3.7 g/cm³, Vickers hardness ≥1500 HV, and dielectric strength >15 kV/mm. The polishing process achieves surface flatness within 0.001mm/mm and parallelism tolerance of ±0.002mm. Available in purity grades from 95% to 99.8% Al₂O₃, higher alumina content yields enhanced mechanical properties but increases manufacturing complexity. Blocks are typically ivory-white but can be produced in black alumina for specialized applications requiring reduced light reflection.

3. How Polished Al₂O₃ Ceramic Plate Alumina Square Block Is Produced

3.1 Forming and Sintering Process

Production begins with high-purity alumina powder (<1μm particle size) mixed with binders and pressed using isostatic compaction (200-300 MPa) for uniform density. Green blocks undergo bisque firing at 1,200°C to remove organic binders before high-temperature sintering at 1,600-1,800°C. This vitrification process achieves >98% theoretical density through controlled heating profiles lasting 24-48 hours. Sintering atmosphere (air/hydrogen) is precisely regulated to prevent oxidation defects and ensure stoichiometric Al₂O₃ formation.

3.2 Precision Polishing Techniques

Sintered blocks undergo multi-stage diamond grinding to achieve basic dimensional accuracy before polishing. The precision polishing sequence progresses through:

1. Coarse polishing with 60-90μm diamond slurry
2. Intermediate polishing with 15-30μm diamond
3. Fine polishing with 3-9μm diamond compound
4. Final chemo-mechanical polishing with colloidal silica

Each stage reduces surface roughness by 50-70%, with the final mirror finish requiring specialized polishing equipment with sub-micron position control. Quality verification includes laser interferometry for flatness and white-light interferometers for surface topography analysis.

4. Application Fields of Polished Al₂O₃ Ceramic Plate Alumina Square Block

4.1 High-Temperature and Semiconductor Applications

In semiconductor manufacturing, these blocks serve as heat-resistant sintering plates for wafer processing, leveraging their ultra-flat surfaces and thermal stability. Their electrical insulation properties make them ideal for plasma etch chambers and CVD reactor components. The photovoltaic industry utilizes them as diffusion plates in solar cell production lines, where they withstand repeated thermal cycling up to 1,200°C. Precision-polished blocks also function as metrology reference standards in cleanrooms due to their non-magnetic properties and dimensional stability.

4.2 Industrial and Specialized Uses

These ceramic blocks serve as wear plates in high-abrasion environments like mining equipment and material handling systems, outperforming steel by 5-8x in service life. The food processing industry employs them as non-contaminating bearing surfaces in filling machines. In energy applications, they function as insulation spacers in fuel cell stacks and battery test fixtures. Medical device manufacturers use polished blocks as sterilization-compatible platforms for surgical instrument assembly. Their biocompatibility also enables use in dental implant manufacturing jigs.

5. How To Choose Quality Polished Al₂O₃ Ceramic Plate Alumina Square Block

5.1 Technical Specifications Evaluation

Select blocks based on measurable parameters: verify alumina content (95-99.8%) through material certificates, with higher purity offering better performance in extreme conditions. Demand test reports for density (≥3.7 g/cm³), surface roughness (≤0.4μm Ra), and flatness tolerance (≤0.001mm/mm). For thermal applications, confirm thermal conductivity (20-30 W/mK) and maximum service temperature (1,550-1,750°C). Critical dimensions should have tolerances of ±0.01mm or better for precision applications. Always request samples for dimensional validation and surface finish inspection under industrial microscopes.

5.2 Manufacturer Qualification Criteria

Prioritize manufacturers with ISO 9001-certified production facilities and material traceability systems. Evaluate their polishing capabilities through sample analysis – quality providers should demonstrate multi-axis CNC polishing equipment. For specialized applications, seek suppliers offering customized ceramic solutions with engineering support. Review their testing protocols: reputable manufacturers conduct 100% dimensional checks, batch-wise density measurements, and periodic microstructural analysis. Consider suppliers providing application-specific surface treatments like laser engraving or anti-static coatings.

6. People Also Ask About Polished Al₂O₃ Ceramic Plate Alumina Square Block

6.1 Performance and Handling Questions

Q: What’s the maximum continuous operating temperature?
A: Standard 95% alumina blocks withstand 1,600°C in oxidizing atmospheres, while 99.5% grades handle 1,750°C. Performance depends on thermal cycling frequency and mechanical load.

Q: How do they compare to zirconia or silicon carbide?
A: Alumina offers better cost-performance balance with superior electrical insulation. Zirconia provides higher fracture toughness, while SiC excels in thermal conductivity but is more expensive.

6.2 Customization and Maintenance Queries

Q: Can these blocks be machined after sintering?
A: Yes, but only with diamond tools. Post-sintering machining increases costs significantly – design components to near-net shape before sintering when possible.

Q: How to clean polished alumina blocks?
A: Use mild detergents in ultrasonic baths. Avoid abrasive cleaners or acid solutions (except phosphoric acid). For particle contamination, use cleanroom-grade wipes with isopropyl alcohol.

Tags: alumina ceramic block, polished Al2O3 plate, alumina square block, precision ceramic plate, high-temperature ceramic block, industrial alumina component, ceramic insulation block, custom alumina plate

(Polished Al2O3 Ceramic Plate Alumina Square Block)

Supplier
Alumina Technology Co., Ltd focus on the research and development, production and sales of aluminum oxide powder, aluminum oxide products, aluminum oxide crucible, etc., serving the electronics, ceramics, chemical and other industries. Since its establishment in 2005, the company has been committed to providing customers with the best products and services. If you are looking for high quality Alumina Ceramic Products , please feel free to contact us.（nanotrun@yahoo.com）