Process for the protection of aln powder against hydrolysis

摘要

The invention relates to a process for protecting aluminium nitride AlN powder against decomposition, i.e. hydrolysis in moist atmosphere or in an aqueous medium. The process for the protection of AlN powder against hydrolysis is characterized in that in a solution of orthosilicic acid or other silicic acid or water-soluble salt thereof with a concentration of from 1 x 10-3 to 5 x 10-1 mole dm-3, AlN powder is dispersed up to a mass fraction of 1 to 50 %, its particles having an average size of from 0.1 mu m to 1 mm, and during dispersion this suspension is not heated above the temperature of 85 DEG C. In the case of dispersion by milling, an organic or inorganic oxidizing agent, typically H2O2, is added to this suspension in the quantity of from 0.01 to 0.1 ml per gramme of AlN powder.