Aluminium oxide is an amphoteric substance, meaning it can react with both acids and bases, such as hydrofluoric acid and sodium hydroxide, acting as an acid with a base and a base with an acid, neutralising the other and producing a salt.
A 3077 (OTTOKEMI) Aluminium oxide sputtering target, diam. x thickness 4 inch x 6 mm, 99.99% Cas 1344-28-1 - used in Physical Vapor Deposition (PVD) to deposit thin, insulating, and highly durable ceramic films.