EN
In the precision machining industry, the intermediate polishing process serves as a vital bridge between rough polishing and mirror polishing. The crystal morphology, particle size stability and impurity control of polishing powder directly affect the machining efficiency, surface qualification rate and production cost of workpieces. Leveraging its mature large-scale high-temperature calcination technology, Greatsun Aopeng Group has developed the AM-21 high-temperature calcined α-alumina medium polishing powder. This product strikes an optimal balance between cutting performance and polishing finish, making it an ideal abrasive for intermediate polishing of both metal and non-metal workpieces. In addition, it is applicable to a wide range of scenarios, including thermal conductive filling and electronic ceramics manufacturing.
Greatsun Aopeng Group’s AM-21 is a fully α-phase alumina powder with a typical Al₂O₃ purity as high as 99.7%. Tailored as a professional abrasive for medium polishing processes, it can also serve as functional filler powder for ceramic blanks and thermally conductive composite materials. Manufactured via rigorous high-temperature calcination treatment, the product features an ignition loss of merely 0.05% and contains no aluminum hydroxide impurities. Its free water content is strictly controlled at 0.10%, guaranteeing superior powder dryness and stability. Additionally, this powder boasts excellent anti-caking performance for long-term storage, low dust generation and outstanding dispersibility.
Impurity control constitutes the core competitive advantage of high-quality polishing powder. As a medium-sodium grade product, Greatsun Aopeng Group AM-21 imposes stringent restrictions on harmful impurities including silicon and iron, with SiO₂ content as low as 0.02% and Fe₂O₃ content merely 0.01%. Its ultra-low iron and silicon content effectively minimizes common defects such as pitting, scratches and yellow stains on workpieces made of stainless steel, aluminum alloy, ceramics and acrylic materials during polishing. This significantly lowers the product defect rate, making the powder well-suited for high-volume precision polishing production lines.
Greatsun Aopeng Group AM-21 features a structurally optimized powder design that delivers well-balanced comprehensive performance. It has a median particle size (D50) of 4.8 μm, commonly rounded to 5 μm in industrial applications, with a stable α-crystal size ranging from 2 to 4 μm and a uniform hexagonal lamellar crystalline morphology. This distinctive lamellar crystal structure empowers the powder with robust cutting capacity, which efficiently eliminates tool marks and oxide layers on workpiece surfaces while maintaining consistent and superior polishing gloss. The product maintains a BET specific surface area of 4–6 m²/g (approximately equivalent to 3000 mesh), a true density of 3.95 g/cm³, moderate flowability and appropriate oil absorption. These properties enable excellent compatibility with both water-based and oil-based polishing fluids, as well as wide adaptability to organosilicon thermal conductivity systems.
The powder boasts superior physical and thermal properties with a Mohs hardness of 9, delivering outstanding grinding and polishing efficiency. It maintains stable phase structure without any phase transition at 1600℃, ensuring exceptional thermal stability. Its fully mature and complete crystal structure provides remarkable wear resistance, effectively extending the service life of polishing consumables and helping enterprises reduce overall abrasive usage costs. In addition, the product exhibits excellent sintering performance, achieving a sintered density of 3.72 g/cm³ after sintering at 1600℃ for two hours, greatly broadening its application scope in advanced ceramics and refractory material fields.
The product features versatile application scenarios, realizing multi-functional utilization with a single material. In the polishing sector, it is applicable to medium and fine polishing of stainless steel, aluminum and copper components, and can also deliver mirror polishing effects for jade, industrial ceramics, glass and resin products. In the functional filling field, it serves as a high-performance thermally conductive filler for thermally conductive silicone rubber and epoxy systems, as well as a key raw material for wear-resistant coatings. Furthermore, it can be used for low-sodium refractory castables and base powder materials for electronic ceramics, fully covering diverse industrial application demands.
As a professional enterprise deeply engaged in aluminum-based new materials, Greatsun Aopeng Group owns independent production lines to support stable mass production. With full-process standardized management, the product delivers excellent batch-to-batch consistency. The AM-21 medium polishing powder is offered in two standard packaging specifications: 25kg kraft paper bags and 1000kg ton bags, enabling flexible supply solutions. Sample testing services are also available for customer performance comparison and verification.
Against the growing market demand for higher quality and efficiency in the manufacturing industry, Greatsun Aopeng Group keeps iterating and optimizing high-performance alumina powder materials. Featuring stable technical indicators, balanced polishing performance and wide applicability, the AM-21 α-alumina medium polishing powder helps polishing fluid manufacturers and precision machining enterprises optimize production processes, achieving efficient processing while delivering high-quality mirror surface finishing. Adhering to strict quality standards, Greatsun Aopeng Group empowers the upgrading of precision manufacturing across various industries with high-performance domestic calcined alumina powder products.
