球形石墨粉末及后处理工艺对SLS石墨原型件的影响

Effect of Spherical Graphite Powder and Post-treatment Process on SLS Graphite Prototype

本实验研究了天然鳞片石墨/酚醛树脂混合粉末、人工合成石墨/酚醛树脂混合粉末的流动性及选择性激光烧结技术(SLS)成型工艺性,并对天然鳞片石墨原型件和人工合成石墨原型件进行二次固化、真空压力浸渍致密化后处理。研究发现,加入球形石墨粉末有助于改善两种石墨/酚醛树脂混合粉末的流动性,提升了天然鳞片石墨/酚醛树脂混合粉末的堆积密度,但降低了人工合成石墨/酚醛树脂混合粉末的堆积密度;在相同条件下,天然鳞片石墨/酚醛树脂混合粉末的流动性更佳;在成形精度方面,人工合成石墨SLS原型件表现为各向同性,而天然鳞片石墨SLS原型件表现为各向异性;人工合成石墨SLS原型件比天然鳞片石墨SLS原型件具有更高的抗弯强度;经过二次固化、真空压力浸渍致密化处理后,人工合成石墨成型件的抗弯强度和导热性能也更佳。

The fluidity of natural flake graphite/phenolic resin mixed powder,synthetic graphite/phenolic resin mixed powder and the forming process of selective laser sintering(SLS)were studied in this paper,and natural flake graphite prototype and synthetic graphite prototype were treated by secondary curing,vacuum pressure impregnation densification.It is found that the addition of Spherical Graphite Powder could improve the flui-dity of the two graphite/phenolic resin powders,the bulk density of natural flake graphite/phenolic resin mixed powder is increased,but the bulk density of synthetic graphite/phenolic resin mixed powder is decreased.Under the same conditions,the fluidity of natural flake graphite/phenolic resin powders is better;in terms of forming precision,the synthetic graphite SLS prototype is isotropic,while the natural flake graphite SLS prototype is anisotropic;the synthetic graphite SLS prototype has higher bending strength than the natural flake graphite SLS Prototype;after secondary curing and vacuum pressure impregnation densification,the bending strength and thermal conductivity of synthetic graphite parts are also better.