Additive manufacturing of polymer-based composites enables the functional tailoring of mechanical and electrical properties through the combined control of printing parameters and post-processing conditions. Tensile specimens and flat strips were printed using 0/90° and − 45/45° raster angles and tested in the as-printed condition and after annealing at 60 °C and 110 °C. For the 0/90° raster, ultimate tensile strength (UTS) changed from 18.19 MPa in the as-printed condition to 20.43 MPa after annealing at 60 °C and to 18.88 MPa after annealing at 110 °C, while Young’s modulus changed from 1.561 to 1.592 and 1.503 GPa, and strain at break from 4.68% to 4.90% and 4.35%. For the − 45/45° raster, UTS changed from 17.03 to 18.37 and 18.05 MPa, Young’s modulus from 1.521 to 1.567 and 1.450 GPa, and strain at break from 4.21% to 4.298% and 4.04% for the as-printed, 60 °C, and 110 °C conditions, respectively. Electrical resistivity of the printed strips was measured after annealing and subsequently evaluated during controlled heating from 25 °C to 110 °C. Annealing reduced electrical resistivity relative to the as-printed condition for both raster angles. For the 0/90° raster, the average temperature coefficients of electrical resistivity (dρ/dT) over 25–110 °C were 5.34, 3.28, and 1.78 Ω·cm/°C for the as-printed, 60 °C, and 110 °C conditions, respectively. In the as-printed 0/90° condition, dρ/dT increased above 70 °C, reaching 10.1 and 9.1 Ω·cm/°C in the 70–90 °C and 90–110 °C intervals.
Frederico de Castro Magalhães (Thu,) studied this question.