Kobayashi Ryuichi, Kigure Takashi, Yamauchi Yuki
Tokyo Metropolitan Industrial Technology Research Institute, Tokyo 135-0064, Japan.
Polymers (Basel). 2024 Nov 25;16(23):3278. doi: 10.3390/polym16233278.
In conventional laser-based powder bed fusion of polymers (PBF-LB/P), aging of the powder due to preheating of the powder bed is a significant issue. This paper proposes a method for low-temperature PBF-LB/P using a semi-sintering process that minimizes powder aging caused by preheating. By partially semi-sintering the low-temperature powder bed, it was possible to execute the PBF-LB/P while avoiding the aging of most of the powder. Furthermore, the suppression of curling by the semi-sintered body eliminated the need to connect the base plate to the parts, which was necessary in previously reported low-temperature PBF-LB/P. Using the semi-sintering process, we successfully built cuboid and tensile test specimens in a polyamide 11 powder bed maintained below the crystallization temperature, where the powder hardly aged. The apparent densities of the built specimens were comparable to those produced using high-temperature PBF-LB/P. However, the elongation in the building direction of the built parts by the semi-sintering process should be improved. This study represents the first step toward the practical application of low-temperature PBF-LB/P using semi-sintering.
在传统的基于激光的聚合物粉末床熔融（PBF-LB/P）工艺中，粉末床预热导致的粉末老化是一个重大问题。本文提出了一种使用半烧结工艺的低温PBF-LB/P方法，该方法可将预热引起的粉末老化降至最低。通过对低温粉末床进行部分半烧结，可以在避免大部分粉末老化的同时执行PBF-LB/P。此外，半烧结体对翘曲的抑制消除了将基板连接到零件上的需求，而在先前报道的低温PBF-LB/P中这是必要的。使用半烧结工艺，我们成功地在保持低于结晶温度的聚酰胺11粉末床中制造了长方体和拉伸试验样品，在该温度下粉末几乎不会老化。所制造样品的表观密度与使用高温PBF-LB/P生产的样品相当。然而，通过半烧结工艺制造的零件在制造方向上的伸长率有待提高。本研究代表了使用半烧结实现低温PBF-LB/P实际应用的第一步。
