Additive manufacturing promises to revolutionize manufacturing industries. However, 3D printing of novel build materials is currently limited by constraints inherent to printer designs. In this work, a bench-top powder melt extrusion (PME) 3D printer head was designed and fabricated to print parts directly from powder-based materials rather than filament. The final design of the PME printer head evolved from the Rich Rap Universal Pellet Extruder (RRUPE) design and was realized through an iterative approach. The PME printer was made possible by modifications to the funnel shape, pressure applied to the extrudate by the auger, and hot end structure. Through comparison of parts printed with the PME printer with those from a commercially available fused filament fabrication (FFF) 3D printer using common thermoplastics poly(lactide) (PLA), high impact poly(styrene) (HIPS), and acrylonitrile butadiene styrene (ABS) powders (< 1 mm in diameter), evaluation of the printer performance was performed. For each build material, the PME printed objects show comparable viscoelastic properties by dynamic mechanical analysis (DMA) to those of the FFF objects. However, due to a significant difference in printer resolution between PME (X–Y resolution of 0.8 mm and a Z-layer height calibrated to 0.1 mm) and FFF (X–Y resolution of 0.4 mm and a Z-layer height of 0.18 mm), as well as, an inherently more inconsistent feed of build material for PME than FFF, the resulting print quality, determined by a dimensional analysis and surface roughness comparisons, of the PME printed objects was lower than that of the FFF printed parts based on the print layer uniformity and structure. Further, due to the poorer print resolution and inherent inconsistent build material feed of the PME, the bulk tensile strength and Young’s moduli of the objects printed by PME were lower and more inconsistent (49.2 ± 10.7 MPa and 1620 ± 375 MPa, respectively) than those of FFF printed objects (57.7 ± 2.31 MPa and 2160 ± 179 MPa, respectively). Nevertheless, PME print methods promise an opportunity to provide a platform on which it is possible to rapidly prototype a myriad of thermoplastic materials for 3D printing.
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This content will become publicly available on June 1, 2025
Powder contamination during laser powder bed fusion: Inconel 718 in Ti6Al4V
Powder contamination during laser powder bed fusion is a critical concern for the quality assurance of parts. Herein, we studied the effect of Inconel 718 contamination on the properties of printed Ti6Al4V, two commonly printed alloys. Contaminated parts exhibited visual and microstructural defects, and a mere 0.5wt% IN718 contamination resulted in a 43% reduction in plastic strain without noticing surface-level cracking. Further contamination of 2.5 wt% IN718 promotes surface cracking that renders the material unable to deform plastically, highlighting the importance of proper powder handling and the detrimental effects that even small amounts of contaminants can have on AM-produced components.
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- Award ID(s):
- 1934230
- NSF-PAR ID:
- 10536683
- Publisher / Repository:
- Elsevier
- Date Published:
- Journal Name:
- Materials Letters
- Volume:
- 365
- Issue:
- C
- ISSN:
- 0167-577X
- Page Range / eLocation ID:
- 136465
- Subject(s) / Keyword(s):
- Laser powder bed fusion Additive Manufacturing Inconel 718 Ti6Al4V Defects Mechanical Properties.
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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