Surface polishing technology is an indispensable key process in the manufacturing industry, which directly affects the appearance quality, optical properties and mechanical properties of the product. Alumina has become an important material in the polishing field due to its high hardness, chemical stability and controllable particle size distribution. Alumina polishing powder is an abrasive widely used in precision polishing, suitable for polishing of various materials such as metals, glass, ceramics, semiconductors, etc.
Classification of Alumina Polishing Powder：
1. According to crystal structure
• α-alumina (corundum): high temperature stable phase, highest hardness, suitable for sapphire and metal polishing.
• γ-alumina: large specific surface area, high activity, suitable for chemical mechanical polishing (CMP).
• Mixed alumina: optimized polishing performance through doping modification (such as Cr, Si).
2. By particle size
|
type |
Particle size range |
Applicable scenarios |
|
Rough polishing |
1–10 μm |
Metal deburring, fast cutting |
|
Fine polishing |
0.1–1 μm |
Glass and ceramic polishing |
|
Super polishing |
<0.1 μm |
Semiconductors, optical components |
3. By purity
• Industrial grade (≥99%): ordinary metal, glass polishing.
• High purity grade (≥99.9%): optical lens, electronic ceramics.
• Ultra-high purity grade (≥99.99%): semiconductor wafers, LED substrates.
Preparation process of alumina polishing powder：
Raw material processing
• Bayer process: extract high-purity alumina from bauxite.
• Sol-gel method: prepare nano-alumina with uniform particle size distribution.
Calcination and classification
• High-temperature calcination (>1200℃): generate α-alumina.
• Air flow milling: control particle size and avoid agglomeration.
Surface modification
• Silane coupling agent treatment: improve dispersibility and reduce polishing scratches.
Application of Alumina Polishing Powder：
1. Semiconductor Industry
• CMP Polishing: Used for planarization of silicon wafers and gallium arsenide (GaAs) wafers, requiring nano-grade γ-alumina.
2. Optical and Display Industry
• Sapphire Polishing: Smartphone lens covers and LED substrates require high-purity α-alumina (0.1–0.5 μm).
• Glass Lens: Reduce surface roughness (Ra <1 nm).
3. Metal Processing
• Stainless Steel Mirror Polishing: Rough Polishing (5 μm) + Fine Polishing (1 μm) Combination Process.
4. Ceramics and Composite Materials
• Electronic Ceramic Substrates: Precision Polishing of Alumina Ceramics.
Alumina polishing powder has become an irreplaceable material in the field of precision manufacturing due to its excellent performance and wide application. In the future, with the rapid development of industries such as semiconductors and new energy, the market demand for high-purity, nano-grade alumina polishing powder will further expand, and technological innovation and process optimization will become the core of industry
competition.