Yu Yueqiang, Ma Tingang, Wang Suling, Jiang Minzheng, Gao Sheng, Guo Yanling, Jiang Ting, Doumbia Bakary S, Yan Bo, Shen Shaorui
College of Mechanical Science and Engineering, Northeast Petroleum University, Daqing 163318, China.
Key Laboratory of Petroleum Mechanical Engineering of Heilongjiang Province, Daqing 163318, China.
Materials (Basel). 2023 Jun 9;16(12):4295. doi: 10.3390/ma16124295.
Powder laying is a necessary procedure during powder bed additive manufacturing (PBAM), and the quality of powder bed has an important effect on the performance of products. Because the powder particle motion state during the powder laying process of biomass composites is difficult to observe, and the influence of the powder laying process parameters on the quality of the powder bed is still unclear, a simulation study of the biomass composite powder laying process during powder bed additive manufacturing was conducted using the discrete element method. A discrete element model of walnut shell/Co-PES composite powder was established using the multi-sphere unit method, and the powder-spreading process was numerically simulated using two different powder spreading methods (rollers/scrapers). The results showed that the quality of powder bed formed by roller laying was better than that formed by scrapers with the same powder laying speed and powder laying thickness. For both of the two different spreading methods, the uniformity and density of the powder bed decreased as spreading speed increased, although the spreading speed had a more important influence on scraper spreading compared to roller spreading. As powder laying thickness increased, the powder bed formed by the two different powder laying methods became more uniform and denser. When the powder laying thickness was less than 110μm, the particles were easily blocked at the powder laying gap and are pushed out of the forming platform, forming many voids, and decreasing the powder bed's quality. When the powder thickness was greater than 140 μm, the uniformity and density of the powder bed increased gradually, the number of voids decreased, and the quality of the powder bed improved.
铺粉是粉末床增材制造（PBAM）过程中的一个必要工序，粉末床的质量对产品性能有重要影响。由于生物质复合材料铺粉过程中粉末颗粒的运动状态难以观测，且铺粉工艺参数对粉末床质量的影响尚不明确，因此采用离散元方法对粉末床增材制造过程中的生物质复合材料铺粉过程进行了模拟研究。采用多球体单元法建立了核桃壳/Co-PES复合粉末的离散元模型，并使用两种不同的铺粉方法（滚筒/刮板）对铺粉过程进行了数值模拟。结果表明，在相同的铺粉速度和铺粉厚度下，滚筒铺粉形成的粉末床质量优于刮板铺粉。对于两种不同的铺粉方法，随着铺粉速度的增加，粉末床的均匀性和密度均降低，尽管铺粉速度对刮板铺粉的影响比对滚筒铺粉的影响更大。随着铺粉厚度的增加，两种不同铺粉方法形成的粉末床变得更加均匀和致密。当铺粉厚度小于110μm时，颗粒容易在铺粉间隙处堵塞并被推出成型平台，形成许多空隙，降低了粉末床的质量。当粉末厚度大于140μm时，粉末床的均匀性和密度逐渐增加，空隙数量减少，粉末床质量得到改善。
