What Is Corundum White?
Corundum white, commonly referred to as white fused alumina (WFA), is a high-purity synthetic abrasive produced by fusing refined alumina in an electric arc furnace at temperatures exceeding 2000 °C.
The material solidifies into a polycrystalline α-aluminum oxide (α-Al₂O₃) structure with extremely low iron content, making it suitable for precision surface processing.
Featured Snippet Definition
Corundum white is a high-purity, polycrystalline aluminum oxide abrasive characterized by high hardness, chemical stability, and low contamination risk, widely used in grinding, blasting, and refractory applications.
Chemical and Physical Characteristics
| Property | Typical Range |
|---|---|
| Main phase | α-Al₂O₃ (polycrystalline) |
| Al₂O₃ content | 99.2–99.6% (grade-dependent) |
| Fe₂O₃ content | ≤ 0.10% |
| Mohs hardness | ~9 |
| Melting point | ~2050 °C |
| Electrical behavior | Insulating |
| Optical transparency | ❌ Not transparent |
Accuracy clarification:
Only single-crystal sapphire exhibits optical transparency. White corundum is a fused, polycrystalline abrasive and should not be described as optically transparent or optical-grade.
How Corundum White Is Manufactured
Industrial production of corundum white generally includes:
- Selection of high-purity alumina feedstock
- Electric arc furnace fusion
- Controlled cooling and solidification
- Crushing, milling, and particle classification
- Magnetic separation and final grading (FEPA / ANSI)
A full overview of available forms and specifications is provided in the internal pillar article:
👉 white corundum product highlights
Industrial Applications of Corundum White
Precision Grinding and Polishing
Thanks to its friable crystal structure, corundum white continuously exposes fresh cutting edges during use. This makes it suitable for:
- Tool and cutter grinding
- Bearing and mold finishing
- Hardened steel surface refinement
Common abrasive form:
🔗 White Fused Alumina Grit
Sandblasting and Surface Preparation
Low iron content reduces the risk of surface contamination, particularly on corrosion-sensitive metals.
Typical uses include:
- Stainless steel blasting
- Aerospace component preparation
- Equipment surface cleaning
Recommended material:
🔗 White Corundum for Sandblasting
Refractory and High-Temperature Applications
Fine white corundum powders are frequently used as:
- Refractory fillers
- Castable aggregates
- Kiln furniture raw materials
Relevant product type:
🔗 White Fused Alumina Powder
Comparative Data: White Corundum vs Other Abrasives
Chemical Purity and Contamination Risk
| Abrasive Material | Al₂O₃ (%) | Fe₂O₃ (%) | Contamination Risk |
|---|---|---|---|
| Corundum White | 99.2–99.6 | ≤0.10 | Very Low |
| Brown Fused Alumina | 95–97 | 0.3–1.0 | Medium |
| Calcined Alumina | ≥99.5 | ≤0.05 | Very Low |
| Silicon Carbide | ≥98 (SiC) | N/A | Low |
Why it matters:
Corundum white is selected not for appearance, but for chemical cleanliness and process stability.
Cutting Behavior and Wear Characteristics
| Abrasive | Cutting Action | Friability | Heat Generation |
|---|---|---|---|
| White Corundum | Medium–High | High | Low–Medium |
| Brown Alumina | Medium | Low | Medium–High |
| Silicon Carbide | Very High | Very High | High |
This balance makes corundum white ideal where surface quality outweighs maximum material removal.
Application Suitability Matrix
| Application | White Corundum | Brown Alumina | Silicon Carbide |
|---|---|---|---|
| Precision grinding | ✅ Recommended | ⚠️ Acceptable | ❌ Too aggressive |
| Stainless steel blasting | ✅ Recommended | ❌ Rust risk | ⚠️ Conditional |
| Refractory fillers | ✅ Suitable | ⚠️ Limited | ❌ Rare |
| Optical or biomedical implants | ❌ Not applicable | ❌ | ❌ |
Trust note:
White corundum is not a biomedical implant material and not an optical material. Its role in medical-related industries is limited to equipment and surface processing, not direct human use.
How to Select a Corundum White Supplier
Professional buyers should evaluate suppliers based on:
- Verified chemical composition reports
- Consistent particle size distribution
- Compliance with FEPA or ANSI standards
- Batch traceability and industrial experience
As a specialized manufacturer of white fused alumina, WF Abrasive supplies graded corundum white materials for grinding, blasting, and refractory applications across multiple industries.
Buyer Summary
- Corundum white is a high-purity alumina abrasive, not sapphire
- Its value lies in low contamination and stable cutting behavior
- Correct grade and grain size selection directly affect performance
- Standards compliance is more important than nominal purity alone
For specifications, grades, and industrial forms, refer to the detailed guide:
👉 white corundum product highlights
