Performance Improvement of Additively Manufactured Complex Configuration of Polyamide 12

In this study, to improve the unsatisfactory mechanical properties of polyamide-12 materials formed via selective laser sintering , an independent soaking and rapid cooling device is developed to improve the internal microstructural defects of the materials via sintering. The maximum tensile strength of the material after heat treatment is 57.3 ± 0.5 MPa at the optimum temperature. Meanwhile, its elongation at break is 293 %–297 % and 22 %–25 % at -80 °C and +80 °C, respectively. At +80 °C, its fracture strength and elongation at break are 53.5 ± 3.2 MPa and 539 %–582 %, respectively. After heat treatment, its maximum bearing capacity of the triply periodic minimal surface (TPMS) in the elastic stage increased significantly by 106 %–119 %. Among them, the d -type TPMS after heat treatment shows the best comprehensive bearing capacity; the maximum bearing capacity in the elastic stage is 7.2 kN, which is accompanied by favorable thermal insulation. At lower-surface temperatures of +80 °C and -80 °C, the equivalent thermal conductivities are 0.02975 and 0.01592 W/(m·K), respectively.