Application Study of Zirconia Powder in High-End Precision Polishing

With the rapid development of high-tech industries such as electronics, optics, semiconductors, and advanced ceramics, the requirements for material surface processing quality have become increasingly stringent. In particular, for ultra-precision machining of critical components like sapphire substrates, optical glass, and hard disk platters, the performance of polishing materials directly determines both processing efficiency and final surface quality. Zirconia powder (ZrO₂), a high-performance inorganic material, has gradually emerged as a new generation of polishing material after cerium oxide and alumina, owing to its excellent hardness, thermal stability, wear resistance, and polishing capabilities.

1. Material Characteristics of Zirconia Powde

Zirconia is a white powder with a high melting point (about 2700°C), and it exists in various crystalline forms, including monoclinic, tetragonal, and cubic phases. By adding stabilizing agents such as yttria (Y₂O₃) or calcia (CaO), zirconia powders can be rendered stable or partially stabilized, maintaining excellent phase stability and mechanical properties at high temperatures.

The outstanding advantages of zirconia powder in polishing applications include:

（1）High hardness and excellent polishing performance: With a Mohs hardness above 8.5, it is suitable for final polishing of hard materials.

（2）Strong chemical stability: It remains inert in acidic or weakly alkaline environments.

（3）Excellent dispersibility: Modified nano- or submicron zirconia powders possess good suspension and fluidity, ensuring uniform polishing.

（4）Low thermal conductivity and minimal friction damage: Reduces thermal stress and microcrack risk during polishing processes.

2. Typical Applications in Precision Polishing

(1) Sapphire Substrate Polishing

Sapphire crystals are widely used in LED chips, watch lenses, and optoelectronic devices due to their hardness and optical transparency. Zirconia powder, with its similar hardness and low-damage polishing mechanism, has become an ideal material for chemical mechanical polishing (CMP) of sapphire. Compared to traditional alumina powders, zirconia provides higher surface flatness, improved gloss, and significantly reduces micro-scratches and surface defects.

(2) Optical Glass Polishing

In the manufacturing of precision lenses, prisms, and optical fiber end faces, polishing powders must meet extremely high purity and fineness requirements. High-purity zirconia powder with a particle size range of 0.3–0.8 μm can achieve ultra-smooth surfaces (Ra ≤ 1 nm), fulfilling the stringent standards of modern optical component processing.

(3) Hard Disk and Silicon Wafer Finishing

As data storage density continues to increase, the surface flatness of hard disk platters has become more critical. Zirconia powder used in the final finishing stages of disk polishing helps minimize defects and enhances writing performance and durability. Moreover, in the ultra-precision polishing of silicon wafers, zirconia exhibits superior surface compatibility and lower abrasive damage, making it a viable alternative to cerium oxide.

3. Influence of Particle Size and Dispersion on Polishing Performance

The polishing performance of zirconia powder is influenced not only by its physical hardness and crystal structure but also by particle size distribution and dispersion behavior:

• Particle Size Control: Oversized particles may cause scratches, while overly fine particles may reduce material removal rates. Particle sizes in the range of D50 = 0.2–1.0 μm are typically selected for different applications.
• Dispersion Quality: Well-dispersed powders prevent agglomeration, maintain slurry stability, and improve processing efficiency. Surface-modified zirconia powders exhibit excellent suspension stability in aqueous or weakly acidic polishing slurries, enabling long-duration continuous operation.

4. Development Trends and Future Outlook

With continuous advancements in nanotechnology and material science, zirconia powder is evolving toward higher purity, narrower particle size distribution, and improved dispersion. Key future directions include:

1. 1. Mass Production and Cost Optimization of Nano-Zirconia
      
      Developing low-cost and scalable production processes for high-purity zirconia powders will expand their industrial applications

 

1. Development of Composite Polishing Materials
   
   Combining zirconia with other materials (e.g., alumina, silica) to enhance removal rates and surface control performance.
2. Eco-Friendly Polishing Slurry Systems
   
   Formulating non-toxic, biodegradable dispersants and additives to meet modern environmental regulations.

5.Conclusion

Zirconia powder is playing an increasingly important role in high-end precision polishing due to its outstanding material properties. As manufacturing technologies evolve and industrial requirements escalate, zirconia-based polishing solutions will continue to expand in application scope. For companies in the polishing and advanced materials sectors, embracing this material upgrade trend and exploring high-end market applications is key to achieving technological leadership and product differentiation.