BN Boron Nitride Ceramic Nozzle for Amorphous Alloy Strip Production

Amorphous strips have excellent soft magnetic properties such as high permeability, high resistivity, and low coercivity, and have broad application prospects. Amorphous alloy soft magnetic material is a new generation of green soft magnetic alloy. Its manufacturing process is short and the production process is energy-saving. It is one of the fastest growing metal materials in the past decade. At present, the amorphous alloy thin strip is mainly produced by the single-roll rapid quenching method. The thickness of the amorphous alloy thin strip mainly depends on the width of the nozzle gap. Generally, the gap width of the nozzle is in the range of 0.3 to 0.9 mm, and the amorphous alloy thin strip that meets the requirements can be obtained. The molten alloy is ejected from the slit of the nozzle, and the moving cooling matrix cools and solidifies at a corresponding rate, thereby producing a continuous amorphous strips.

Nozzle is a key component in the realization of rapid alloy solidification device. The harsh working conditions require the nozzle to have excellent thermal shock resistance, high-speed airflow resistance, erosion resistance of high temperature molten metal, corrosion resistance of molten alloy and oxidation resistance. Because bn-based ceramics have good thermal shock resistance and processability, they are suitable for the preparation of amorphous thin ribbon nozzles. However, the pure boron nitride material has weak resistance to thermal stress and mechanical stress impact. After a period of use, the nozzle will be deformed and the nozzle will be impacted by the molten liquid into a flow channel, resulting in uneven thickness of the ejected strip. To this end, UNIPRETEC developed BN-2300 and BN-3000 as nozzle materials.