Mechanical properties of CF-reinforced PLA parts manufactured by fused deposition modeling:

Many parameters of fused deposition modeling (FDM) influence the resulting mechanical properties. This can become a key factor if those parts are intended for commercial applications. This study focuses on the influence of nozzle temperature and infill line orientations for parts made with short carbon fiber (CF)-reinforced polylactic acid (PLA). Tests bars made of PLA and PLA-CF composite were produced under carefully selected conditions. As expected, PLA-CF yields higher tensile properties compared to PLA, owing to the strengthening effect of high modulus CFs. Maximum tensile properties are attained for a nozzle temperature of 230°C, for both PLA and PLA-CF. This temperature was thus selected for probing the effects of infill orientations in test bars. Among the multiple orientations tested, the combination [0°, 15°, −15°] relative to the long axis of the test bar yields the highest levels of tensile properties for both PLA and PLA-CF over the “all-purpose” [45°, 135°] orientation. Annealing can also af...