Wolff Sarah J, Wu Hao, Parab Niranjan, Zhao Cang, Ehmann Kornel F, Sun Tao, Cao Jian
Department of Mechanical Engineering, Northwestern University, Evanston, IL, 60208, USA.
School of Mechanical Engineering and Automation, Northeastern University, Shenyang, 110819, People's Republic of China.
Sci Rep. 2019 Jan 30;9(1):962. doi: 10.1038/s41598-018-36678-5.
Powder-blown laser additive manufacturing adds flexibility, in terms of locally varying powder materials, to the ability of building components with complex geometry. Although the process is promising, porosity is common in a built component, hence decreasing fatigue life and mechanical strength. The understanding of the physical phenomena during the interaction of a laser beam and powder-blown deposition is limited and requires in-situ monitoring to capture the influences of process parameters on powder flow, absorptivity of laser energy into the substrate, melt pool dynamics and porosity formation. This study introduces a piezo-driven powder deposition system that allows for imaging of individual powder particles that flow into a scanning melt pool. Here, in-situ high-speed X-ray imaging of the powder-blown additive manufacturing process of Ti-6Al-4V powder particles is the first of its kind and reveals how laser-matter interaction influences powder flow and porosity formation.
粉末送料激光增材制造在局部改变粉末材料方面增加了灵活性，从而具备制造复杂几何形状部件的能力。尽管该工艺前景广阔，但在制造的部件中孔隙率很常见，从而降低了疲劳寿命和机械强度。对激光束与粉末送料沉积相互作用过程中的物理现象的理解有限，需要进行原位监测以捕捉工艺参数对粉末流动、激光能量在基体中的吸收率、熔池动力学和孔隙形成的影响。本研究引入了一种压电驱动的粉末沉积系统，该系统能够对流入扫描熔池的单个粉末颗粒进行成像。在此，对Ti-6Al-4V粉末颗粒的粉末送料增材制造过程进行的原位高速X射线成像尚属首次，揭示了激光与物质的相互作用如何影响粉末流动和孔隙形成。
