PSI - Issue 56

Dan Ioan Stoia et al. / Procedia Structural Integrity 56 (2024) 90–96 Author name / Structural Integrity Procedia 00 (2019) 000–000

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A notable drop in properties can be observe for the one trace and two traces samples (figure 6 d and e). This low tensile strength and elongation compared to the air-printed and raw filament can be explained as a combined effect of faster cooling rate of the samples (due to their sizes) and the deformed shape of the cross section and overall texture. Table 1 shows the tensile strength and elongation at break for all specimen types as average and standard deviation. The higher standard deviation for one and two deposition traces shows a large variability of the testing data, which is an indicator of a low process stability when comes to only one or two printed traces. The very low elongation at break in one and two traces compared to the raw filament is the indicator of rapid cooling of this samples. In conclusion, the material printed on the build platform has lower mechanical properties compared to the raw filament and respectively to air-printed one.

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Fig. 6. Stress strain curves for tensile tested (a) raw filament; (b) air extruded; (c) fourteen deposited traces; (d) two deposited traces; (e) one deposited trace; (f) representative curves for all samples.