FEATURE / Z-PINNING ADDITIVE MANUFACTURING Figure 8. Boundary and material conditions on stock model. a needle composed of 304 stainless steel. Nickelplated brass has favorable thermal properties that make it a great choice for the base of a nozzle due to excellent heating of the filament. While having the penetrated nozzle created with stainless steel provides a baseline as one of the most common nozzle materials, as well as being physically strong enough to handle fibrous material being pushed through a thin-walled structure without damage. The McMaster-Carr's length also is long enough so that the filament has enough space to cool, revealing where in the nozzle the material will become too solid to flow. Additionally, another model was created with a brass needle to investigate Location Material Extended Nozzle (304-SS) 304 Stainless Steel Thermal Properties K = 0.0498 W / (mm °C) a = 1 x 10-7 m / (m °C) cp Extended Nozzle (Brass) Brass = 1000 J / (kg °C) e = 0.0919 [32] K = 0.115 W / (mm °C) a = 2.05 x 10-5 cp Table 3. Extended nozzle material properties. m / (m °C) = 380 J / (kg °C) e = 0.03 Figure 9. Meshed extended nozzle model (with boundary conditions). a nozzle with better thermal properties but, worse toughness. Boundary conditions were set the same as the stock nozzle for all components (Figure 9), while the only change being the steel nozzle would use 304 stainless steel and a brass extended nozzle was modeled as well, these are recorded in Table 3. RESULTS The initial thermal analysis of the stock nozzle was conducted using the boundary defined in Figure 8 with material conditions defined in Table 2. The goal for this study was to determine what benchmark results were and to verify that the model and simulation were indeed set up correctly. The filament will cool to 212.2°C at nozzle exit. The Figure 10. Thermal analysis of stock nozzle at 225°C. 34 | SAMPE JOURNAL | JULY AUGUST 2022 www. sampe.orghttp://www.sampe.org