Powder plasma spheroidization treatment and the characterization of microstructure and mechanical properties of SS 316L powder and L-PBF builds. | LitMetric
United States Naval Academy, 590 Holloway Rd, Annapolis, MD, 21042, USA.
Published: June 2023
AI Article Synopsis
Article Abstract
A plasma spheroidization treatment was applied to stock stainless steel 316L powder for additive manufacturing. The normal and treated powders were compared both in the powder state as well as in the resulting laser powder bed fusion (L-PBF) builds. The plasma spheroidization process slightly increased treated powder aspect ratio and sphericity and shifted the size distribution to larger diameters relative to the normal powder. The normal powder was austenitic in nature whereas the plasma spheroidization process introduced a small fraction (∼3.5 vol %) of ferrite in the treated powder. Ferrite in the powder was not retained in the printed samples and was not shown to negatively affect the build quality. Porosity areal fraction was generally smaller in the treated powder builds. The normal powder builds had a 6% higher yield strength than treated, however the scatter was significantly larger in the 45° and horizontal orientations compared to the treated powder builds.
In this study, the induction plasma spheroidization (IPS) technique was adopted to improve the microstructure and properties of the traditional agglomerated ZrO-7wt%YO (YSZ) powders used in thermal barrier coating (TBC) applications. Compared with agglomerated YSZ powders, IPS-treated powder has a more desirable microstructure, and the overall performance of the spray powders for TBC preparation is significantly improved. Specifically, IPS-treated powder has a dense, solid, defect-free, and chemically uniform microstructure, and its apparent density, flowability, and powder strength are significantly improved, which is believed to substantially enhance the coating performance when prepared with this IPS-treated powder.
A plasma spheroidization treatment was applied to stock stainless steel 316L powder for additive manufacturing. The normal and treated powders were compared both in the powder state as well as in the resulting laser powder bed fusion (L-PBF) builds. The plasma spheroidization process slightly increased treated powder aspect ratio and sphericity and shifted the size distribution to larger diameters relative to the normal powder.
In this work, three kinds of tungsten powders with different particle sizes were spheroidized by radio-frequency (RF) inductively coupled plasma spheroidization. The spheroidization behavior of these tungsten powders was investigated and compared. The spheroidization effects of irregular tungsten powder improves with the decrease in degree of agglomeration and increases with primary particle size.
Wind power is a promising electricity source. Nevertheless, wind turbine blade icing can cause severe problems in turbine operation. In this study, SiO spherical nanoparticles (∼90 nm), produced by RF (radio frequency) plasma spheroidization, were mixed with E51, PDMS, and ethyl acetate, and sprayed on the surface of aluminum plates and regular power windmill fan blades which were already coated with polyurethane primer.
This work focuses on the fabrication of lanthanum cerate (LaCeO, LC) powders via two chemical routes: modified Pechini sol-gel method and solid-state synthesis. The synthesized LC powders were heat treated in the temperature range of 1000-1400 °C for 6 h and investigated as a material for thermal barrier coating (TBC) applications. For this purpose, the powder morphology, chemical composition, crystal structure and thermal stability were studied.
