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Materials Science in Additive Manufacturing Spheroidization of 304L SS powder for LPBF process

A B

C

Figure 12. Comparison of the tensile properties of parts built using as-received and spheroidized powders. (A) Yield strength. (B) Ultimate tensile strength.
(C) Strain at break.

the reduction in C and Cr decreased the tensile properties reduction in the part made with the spheroidized powder .
[43]
of fabricated parts. It is known that C and Cr are usually The results of density measurement using Archimedes
added to the austenite stainless steels to stabilize the method for the fabricated parts with the as-received and
austenite and to create and disperse carbides. They also spheroidized powders were not statistically significantly
reported that lower oxygen leads to increased ductility. different (P > 0.05) with a mean density of 7.93 g/mL. The
Thus, the higher ductility of the parts fabricated with the lack of pores in the fractographs and the minimal change in
spheroidized powder can be attributed to reduced oxygen density suggest that the stark difference in ductility is not
content in the spheroidized powder. due to pores. Instead, the tensile response of the materials
Two representative samples of typical fracture surfaces is a consequence of the chemistry and the resulting
of parts built with the as-received and spheroidized powders microstructure. As mentioned before, one of the significant
are shown in Figure 13. The ductility difference between the differences in the chemistry of the 2 powders was found
2 parts is readily apparent, as evidenced by the larger area in the nitrogen content. Using this knowledge, JMatPro
[44]

Volume 1 Issue 1 (2022) 8 http://doi.org/10.18063/msam.v1i1.1