Abstract Powder spreading in Additive Manufacturing (AM) has been analysed extensively by the Discrete Element Method, but without considering the presence of ambient gas. For fine particles, as commonly used in AM, the gas drag could affect the quality of spread layer. Here, we consider the dynamics of powder spreading by a roller for a gas-atomised metal powder and analyse the combined effects of gas-particle interaction and interparticle adhesion on the particle flow in the heap and spread layer uniformity. In the presence of gas, the convection and circulation of particles within the heap are slowed down, and the heap repose angle becomes steeper. The amount of particles spread on the base is reduced, as compared to the case in which gas drag is not considered, but surprisingly particles with larger interparticle adhesion form a more uniform spread layer with larger total particle volume when gas drag is taken into account.

中文翻译：

---

增材制造中气体-颗粒相互作用对辊子铺展过程的影响

摘要 增材制造 (AM) 中的粉末铺展已通过离散元方法进行了广泛分析，但未考虑环境气体的存在。对于细颗粒，如 AM 中常用的，气体阻力会影响铺展层的质量。在这里，我们考虑了气体雾化金属粉末通过辊子铺展的动力学，并分析了气体-颗粒相互作用和颗粒间粘附对堆中颗粒流动和铺展层均匀性的综合影响。在气体存在的情况下，堆内粒子的对流和循环减慢，堆休止角变陡。与不考虑气体阻力的情况相比，散布在底座上的颗粒数量减少了，