PSI - Issue 53

Alessandro Greco et al. / Procedia Structural Integrity 53 (2024) 178–184 Author name / Structural Integrity Procedia 00 (2019) 000–000

180

3

2. Materials and Methods The testing campaign was designed by considering two printing process parameters (Fig. 1) and one post-process treatment as input: layer height, infill pattern, annealing. The structure of the full-factorial Design of Experiment (DoE) and the combinations of the parameters were reported in Tables 1 and 2, respectively. Three specimens per each configuration were tested. Specimens were manufactured according to ASTM D638 requirements (see. Fig. 2.a) by MiniFactory ULTRA 3D printer, fixing the printing parameters reported in Table 3. All the specimens were made of Evonik's INFINAM® PEEK 9359 F with diameter filament equals to 1.75 mm. Before each printing process, the filament was dried for 12 h at 100 °C and housed, subsequently, in the humidity-controlled chamber. Simplify 3D  slicing software was used to prepare the printing files.

Table 1. DoE structure. Parameter

Levels

Layer height [mm]

0.15

0.25

Infill pattern

Triangular

Rectilinear (±45 deg)

Annealing temperature [°C]

-

220

Table 2. Parameters combinations.

Series

Layer height [mm]

Infill pattern Triangular Rectilinear Triangular Rectilinear Triangular Rectilinear Triangular Rectilinear

Annealing temp. [°C]

1 2 3 4 5 6 7 8

0.15 0.15 0.25 0.25 0.15 0.15 0.25 0.25

- - - -

220 220 220 220

Table 3. Fixed printing parameters. Parameter

Value

Nozzle temperature [°C] Chamber temperature [°C]

445

155 200 100 720

Bed temperature [°C]

Infill density [%]

Printing speed [mm/min]

Walls

2 (0.8 mm)

Bottom/Top layer Specimen orientation

2 (  45° - lines)

flat

The amount of material for each series is: 5909 mm 3 (7.80 g) for series 1; 5670 mm 3 (7.48 g) for series 2; 5935 mm 3 (7.83 g) for series 3; 5736 mm 3 (7.57 g) for series 4.