Warm isostatic pressing (WIP'ing) of GS44 Si3N4 FDC parts for defect removal

Microstructural Characterization and Mechanical Properties of Si3N4 Formed by Fused Deposition of Ceramics

“… * Samples were subjected to a warm isostatic pressing in the green state in a failed attempt to eliminate the intentionally placed defects 19 …”

“…The microstructure of the FDC parts was examined by optical microscopy. X‐ray radiography was performed in an earlier study and density‐limiting voids resulting from improper build conditions, road widths, and tool paths were identified 19 . These defects were eliminated in the current study by using altered vector patterns near contours and perimeters to insure complete filling of all space and by using a negative gap offset (partial overlapping of adjacent road vectors).…”

“…Ã Samples were subjected to a warm isostatic pressing in the green state in a failed attempt to eliminate the intentionally placed defects 19. www.ceramics.org/ACT Characterization and Properties of Si 3 N 4 Formed by Fused Deposition of Ceramics…”

Additive manufacturing of silicon nitride ceramics: A review of advances and perspectives

“…Fortunately, the research on the AM of Si 3 N 4 ceramic has received more and more attentions recently, and attempts have been on the rise. AM technologies of Si 3 N 4 ceramics mainly include (1) powder bed fusion (including selective laser sintering [SLS], and selective laser melting [SLM], 43–49 and so on), (2) photopolymerization (usually including stereolithography apparatus [SLA], 50 laser‐induced slip [LIS] casting, 51 digital light processing [DLP], 52–65 liquid crystal display [LCD], 66,67 and so on); (3) material extrusion (usually including direct ink writing [DIW] or robocasting, 68–74 fused deposition modeling [FDM], 75–79 and so on); and (4) other AM technologies (including binder jetting [BJ], 80–85 3DP, 86–89 and laminated object manufacturing [LOM] 90–94 ). Schematics of the previous AM technologies for Si 3 N 4 ceramic are illustrated in Figure 2.…”

Biopolymer‐Based Gel Casting of Ferroelectric Ceramics

“…Sigmund et al have reviewed a variety of these novel shape‐forming technologies for advanced ceramics, in particular layer‐based, solid freeform fabrication (SFF) approaches. While promising, additive manufacturing technologies do present challenges in terms of obtaining high density, defect‐free ceramics . An alternative approach is based on subtractive rapid prototyping, where a ceramic preform is green‐machined prior to sintering, which has been successfully applied to bio‐ceramic processing .…”