论文类型：期刊论文
发表刊物：Polymers
收录刊物：SCI
学科门类：工学
一级学科：机械工程
文献类型：J
卷号：14
期号：12
关键字：powder spreading; short fiber; packing quality; roller rotation pattern; discrete element method; selective laser sintering
DOI码：10.3390/polym14122345
发表时间：2022-06-09
影响因子：4.967
摘要：In this study, for the first time, a forward-rotating roller is proposed for the spreading of CF/PA12 composite powder in the selective laser sintering (SLS) process. The mesoscopic kinetic mechanism of composite particle spreading is investigated by utilizing the “multi-spherical” element within the discrete element method (DEM). The commercial software EDEM and the open-source DEM particle simulation code LIGGGHTS-PUBLIC are used for the simulations in this work. It is found that the forward-rotating roller produces a strong compaction on the powder pile than does the conventional counter-rotating roller, thus increasing the coordination number and mass flow rate of the particle flow, which significantly improves the powder bed quality. In addition, the forward-rotating pattern generates a braking friction force on the particles in the opposite direction to their spread, which affects the particle dynamics and deposition process. Therefore, appropriately increasing the roller rotation speed to make this force comparable to the roller dragging force could result in faster deposition of the composite particles to form a stable powder bed. This mechanism allows the forward-rotating roller to maintain a good powder bed quality, even at a high spreading speed, thus providing greater potential for the industry to improve the spreading efficiency of the SLS process.
发布期刊链接：https://www.mdpi.com/2073-4360/14/12/2345/htm