Stability of Y–Ti–O nanoparticles during laser melting of advanced oxide dispersion-strengthened steel powder

Alternative Fabrication Routes toward Oxide-Dispersion-Strengthened Steels and Model Alloys

“…Additive manufacturing technologies such as selective laser melting (SLM), [65][66][67][68] selective laser sintering (SLS) [69] and electron beam melting (EBM) [70] are now well-recognized as capable for efficiently producing complex-shaped, dense parts from metal powders. The use of these techniques to produce parts from mechanically alloyed ODS steel powders provides significant opportunity, as well as additional challenges in preserving the dispersion and size of oxides through the re-melting process.…”

Oxide dispersion strengthened stainless steel 316L with superior strength and ductility by selective laser melting

“…The size of nanoinclusions obtained in this study shows little difference with previous studies using 40 nm ceramic precursor powders. [18,23] No severe precipitations or agglomeration of nanoinclusions existed in the bulk section (away from surface) of samples ODS-0 and ODS-1 while some micro-sized agglomerations were traced in sample ODS-2.…”

“…[17] Chang et al used a laser beam to melt a powder mixture of steel and Y2O3 (20-50 nm) on the steel surface and observed the formation of Y2Ti2O7 oxide particles that coarsened to 150 nm due to the active agglomeration of Y-Ti-O nanoinclusions, carbides and Ar bubbles. [18] Vasquez et al achieved 98% of density and the fine dispersion of nanosized Y-Ti-O particles by using a powder mixture (steel, Y2O3 and TiH2 ) prepared by ball milling for extended duration of 176 hours. [19] Boegelein et al fabricated ferritic ODS-PM2000 samples by SLM from a pre-alloyed powder, in which non-randomly occurred voids, up to 150 µm in size, and inclusions up to 50 µm in size were observed.…”

Laser Powder Bed Fusion of ODS 14YWT from Gas Atomization Reaction Synthesis Precursor Powders

“…Many studies using laser powder bed fusion (LPBF) AM have utilized ferritic or austenitic steels mechanically alloyed with Y 2 O 3 as AM feedstock. [10][11][12][13][14][15][16][17][18][19][20] Alternatively, low-energy ball milling and blending, [21][22][23] along with methods to deposit oxides onto powders in situ, have been reported as alternative feedstock techniques for fabrication by AM. [24][25][26][27][28] While some promising results have been reported, challenges related to heterogeneity and agglomeration of pre-existing Y 2 O 3 remain, and these approaches typically depend on MA processing, which can be a limiting factor to scalability.…”