SLS制备PS/Al_2O_3纳米复合材料中无机纳米粒子的行为特征

Study on the Behavioral Characteristics of Inorganic Nano-Particles in PS/Al_2O_3-Reinforced Nano-Composite Fabricated by SLS

基于选区激光烧结(SLS)技术进行了制备PS/Al2O3纳米复合材料的研究。对PS粉末与纳米Al2O3粒子(5%)的混合粉末进行了选区激光烧结成型实验,并采用传统热模压实验对比进行了比较。其SEM结果表明:SLS技术相比较热模压工艺,无机纳米Al2O3粒子在PS基体中分散均匀,没有热模压成型中存在的大量纳米团聚现象。并讨论分析了SLS更趋于获得无机粒子分散均匀的纳米复合材料的原因,提出了无机纳米Al2O3粒子在混合粉末SLS作用下存在“微飞溅”、“扩散迁移”、“流动渗透”三种行为特征,得出了SLS具有打破纳米粒子团聚、驱散纳米粒子聚集和促进纳米粒子流动的作用。

Selective laser sintering （SLS） is one of the most attractive rapid prototyping techniques due to its suitability to process almost any powder material. This paper has studied the process of fabricating the polystyrene and Al2O3nano-composites by SLS, and experimented with the traditional hot modeling process as to draw comparison between them. Under the SEM micrographs, their behaviors were identified by observing the dispersion of nano-particles in the specimens respectively made by SLS processing and convention modeling. It was also analyzed why it is beneficial to obtain PS/ Al2O3 nano-composites of inorganic nano-particles that are in dispersed uniformity at the help of SLS technology. Furthermore, it puts forward three kinds of behaviors of nano-particles during the laser-sintering process as well, namely ＂slightly splashing＂ under the laser beam, ＂diffusely moving＂ with the polymer melt pool expending, and ＂infihrating＂ with liquid polymer into the cranks and voids in the consolidated layer. The above conclusions suggest that SLS process has the functions of breaking up the congregating of nano-particles, diffusing the gathering of nano-particles and promoting the moving of nano-particles.