There are many methods to produce metal powders from valuable metals and alloys such as titanium, aluminium, stainless steel, iron, copper, nickel base alloys and cobalt base alloys. Atomisation is generally viewed as the best way due to the geometrical properties of the powder particles that can be achieved and thus is ideal for usage in additive manufacturing. For gas atomisation, water atomisation and direct reduction, appropriate gases and gas technologies are required:
- Gas atomisation: argon and nitrogen
- Water atomisation followed by oxide reduction under hydrogen atmosphere
Making quality metal powder
In the atomisation process the melted metal alloys are first refined and degassed, then poured into a gas nozzle, where the liquid material is disintegrated into metal powder by a high-pressure gas stream. Gases such as argon, nitrogen and helium are necessary to prevent excessive oxidation. Linde’s high-pressure gas supply schemes and technologies are used to atomise high-alloy metals to powder particles that are spherical in size and uniform in density.