Share this page by mail What alumina powder grain sizes are available for industrial applications?
Final Advanced Materials produces a very wide range of alumina powders to suit various industrial projects. Series 100 alumina powders can be used for precision sanding and micro-sanding applications with a d50 particle size of 1.5 µm to 2 mm. The series 1,000 has a d50 particle size ranging from 0.05 µm to 3 µm and can be used for metallographic and mineralogical polishing applications. The 900 and 1,500 series can be used for filtration applications with particle sizes of 78 µm to 10 mm.
Final Advanced Materials' hexagonal boron nitride (h-BN) is an excellent high-temperature dry lubricant due to its layered structure similar to that of graphite. It remains stable up to 900°C in air and 2,500°C in a vacuum or inert atmosphere. It also has a thermal conductivity of 30 to 60 W/(m·K). Its low hardness (~2 GPa) and low friction coefficient (~0.15) effectively reduce of wear. Unlike graphite, it offers good performances in an oxidising environment. Final Advanced Materials recommends h-BN powders for applications such as dry lubrication, mould release and high-temperature surface protection.
The choice depends on the desired thermal performance for the resin or composite. Aluminium nitride (AlN) powders increase thermal conductivity up to 150 to 200 W/(m·K), but also provide effective electrical insulation. Boron nitride powders (h-BN) increase thermal conductivity up to 40 to 60 W/(m·K) and thermal stability up to 800–900°C in air, providing a balance between conductivity and ease of application. Alumina powders (Al₂O₃), which are more cost-effective, provide a more moderate conductivity of 20 to 35 W/(m·K). Final Advanced Materials recommends adjusting the particle size and the load level to optimise overall performance.
The choice of ceramic powder depends on the wear constraints and working conditions (load, temperature, environment). Alumina powders (Al₂O₃), with a hardness of 15 to 20 GPa and a density of approximately 3.9 g/cm³, provide an excellent abrasion resistance for standard applications.
For more severe applications, silicon carbide (SiC) powders have a higher hardness of 20 to 28 GPa, a thermal conductivity of up to 120 to 180 W/(m·K) and a very effective thermal resistance up to 1,400–1,600°C. Silicon nitride (Si₃N₄) powders, with a hardness of 15 to 18 GPa, stand out for their mechanical and thermal shock resistance. Final Advanced Materials recommends adjusting the particle size and purity to maximise wear resistance.