Cui Xiaojie, Su Xinlei, Liu Yan, et al. Effects of Gas Atomization Process on Particle Dimension of High-entropy Alloy Powders[J]. Special Casting & Nonferrous Alloys, 2022,42(4):441-445.
Cui Xiaojie, Su Xinlei, Liu Yan, et al. Effects of Gas Atomization Process on Particle Dimension of High-entropy Alloy Powders[J]. Special Casting & Nonferrous Alloys, 2022,42(4):441-445. DOI: 10.15980/j.tzzz.2022.04.009.
The FeCrMnCoNi high-entropy alloy powders were fabricated by gas atomization method
and the influences of atomization pressure and test tube diameter on powder particle dimension were investigated. The results indicate that with the increase of the atomization pressure
the proportion of powders with particle dimension below 100 μm is increased from 57% to 72%
and the mean particle dimension is decreased from 82.6 μm to 44.2 μm. As the pore diameter of the test tube decreases
the proportion of powders with a diameter less than 100 μm is decreased from 79% to 49%
and the mean particle dimension is increased from 40.3 μm to 103.9 μm. The calculation for the cooling rate of droplets reveal that the cooling rate of droplets with a diameter of 10~200 μm is between 3.8×10~4 K/s and 4.3×10~6 K/s
and the rapidly cooled droplets are prone to adhere to the surface of incompletely cooled large droplet. Therefore
the larger the particle dimension of the powder is
the more satellite spheres adhered on the surface is. The larger the droplets obtained by atomization is
the smaller the degree of subcooling is
the greater the powder crystal grains is
and the clearer the dendritic structure is. The decrease in cooling rate also leads to the transformation of internal structure of powder from cellular crystals to mixture of cellular and columnar crystals and then to form dendrites.