Aluminum nitride (AlN) powder is a ceramic material with good thermal conductivity and electrical insulation properties. It can be used as a filler in polymer-based materials to produce conductive potting compounds and thermal pads that improve the overall performance of the resin or plastic part it is being added to. The low thermal expansion coefficient of this material, combined with its superior electrical properties and resistance to attacks by most molten metals makes it an excellent choice for manufacturing high-temperature ceramic parts such as thermally conductive substrates, heat radiation plates, furnace tools and components, crucibles and liners, and corrosion resistant coatings.
HM offers a variety of AlN powders to meet specific customer applications. Depending on the application, these powders can be produced either by direct nitridation or carbothermal reduction-nitridation of alumina. Both techniques produce different AlN particle shapes and sizes, which entails significant differences in production costs.
Direct nitridation produces a AlN body with a spherical shape and a predetermined particle size distribution. While this form of AlN is relatively easy to machine in its green or biscuit state, the sintering process that it undergoes can cause it to shrink up to 20%. This can make it difficult to hold tight tolerances in some shapes.
Carbothermal reduction-nitrided AlN, on the other hand, has a more irregular shape and a wide range of particle sizes. This form of AlN can be machined into complex geometries without the dimensional changes caused by sintering. It can also be made into a variety of products that are not possible to manufacture with the direct nitridation method, including copper metalized AlN tapes and net-shaped complex 3D structures.