Home / News & Blog / Abrasive Blog / 6 Key Questions About White Fused Alumina Abrasive Grains
Brown fused alumina abrasive grains are made from clay, iron filings, and anthracite through high-temperature smelting. They exhibit excellent grinding power, making them particularly suitable for rough polishing and processing, with high efficiency. White fused alumina abrasive grains are produced using alumina powder. The higher the quality of white fused alumina, the finer its grains, and it is highly impact-resistant and wear-resistant.
Brown fused alumina abrasive grains come in various forms, including segment sand, fine powder, and micro-powder. Its hardness is second only to diamond, making it ideal for manufacturing grinding wheels, abrasive tools, and cutting instruments. White fused alumina is a crystalline compound with a hardness higher than brown fused alumina. However, the production cost of white fused alumina is higher, its yield is lower than other abrasive grains, and its price is higher.Besides its price advantage over white fused alumina, brown fused alumina has high purity and excellent flowability, making it popular among various market groups.
The colors of these two abrasive grains differ significantly; as their names suggest, white fused alumina is white, while brown fused alumina is brownish.
White fused alumina grain sizes: 46, 60, 80, 100.
White fused alumina segment sand sizes: 0-1mm, 1-3mm, 3-5mm, 5-8mm, 8-12mm.
White fused alumina fine powder: 325-0.
White fused alumina micro-powder: w5, w7, w63, w10, w14.
Hydrophilicity refers to the ability to attract water molecules. Many material surfaces contain molecules with polar groups, making them highly water-attractive and easily wettable. Generally, abrasive grains possess such properties, and white fused alumina exhibits better hydrophilicity due to the nature of its raw materials.
Hydrophilicity significantly affects the bonding degree between white fused alumina sand and the binding agent. Generally, better hydrophilicity results in a stronger bond. Conversely, poor hydrophilicity leads to weaker bonding. The hydrophilicity required varies depending on the product, processing methods, chemical composition, and surface quality.
Strong hydrophilicity enhances the bonding of abrasive grains with binders when manufacturing abrasive tools. However, overly strong hydrophilicity may cause issues, such as water or oil infiltration into the white fused alumina during storage, leading to agglomeration and severely impacting quality and performance.
The main reason for red discoloration in white fused alumina abrasives is the presence of iron-based substances in the bonding agent used during production or excessive contact with iron during the processing stages.
Solutions: Minimize the presence of iron-based substances in white fused alumina products. To achieve optimal performance, avoid air exposure during abrasive production, and pay attention to controlling the grain size of white fused alumina to prevent undesirable effects.
Despite its excellent performance, white fused alumina abrasive grains may develop cracks after prolonged use.
Solutions to address cracking:
1.Lower the casting temperature and speed to reduce the shrinkage and wear of the alumina crucible.
2.Place chill irons at hotspots during casting and apply thermal insulation coverings at the alumina crucible riser.
3.Strengthen deoxidation measures during the smelting process.
4.Improve the performance of alumina hollow sphere bricks to achieve better density and uniform chemical composition.
Alumina is one of the primary materials forming white fused alumina. The alumina content directly determines its quality. White fused alumina is categorized into three grades, with Grade 1 being the best, followed by Grade 2 and Grade 3. The primary quality standard is based on the Al2O3 content, with content exceeding 95% classified as Grade 1 white fused alumina. Grades 2 and 3 have progressively lower content and quality.
White fused alumina is made from carbon, bauxite, and iron filings. Due to the color of the iron filings, high-quality white fused alumina should exhibit a brown hue. Observing its color is one method to distinguish its quality.
