Characterization of metallic powders atomized using a De Laval nozzle

Gas atomization of liquid metal using a De Laval nozzle is one of the most efficient processes in terms of powder quality including size and composition criteria and in terms of inert gas consumption used to atomize the liquid metal. However, the comprehension of the involved events is at that time of prime importance to optimize this process and the researches are focused on both experimental and modelling approaches. For example, very few experimental data are available on the liquid metal atomization because of the difficulty to achieve measurements very close to the atomization area.
The paper concerns some experimental results obtained with Fe-Al 28% metal spraying. Different techniques (MEB, EDS, RX) were used to characterize the properties of this produced powder. The morphology, the microstructure and the hardness were also analyzed as a function of the diameter of the powder. The evolutions of the powder characteristics during the atomization process were determined as well as some relationships between the powder properties and the operating conditions.