Abstract: In laser powder bed fusion additive manufacturing systems, the airflow circulation system serves not only as an oxygen barrier but also plays a crucial role in creating an airflow field within the build area. This airflow field primarily removes process by-products such as smoke and spatter, which are generated during the forming process and significantly impact the quality of the fabricated parts. Based on the issues of excessive spatter and residual smoke in the RS450 laser selective melting and forming equipment manufactured by Nanjing Zhongke Yuchen, simulation and modeling of the flow channels in the air duct and the overall build chamber were conducted using software tools such as SolidWorks and AnsysFluent. Subsequently, a novel waveform air inlet duct structure was proposed and optimized, taking into account practical requirements and simulation results. The simulation data indicated that the uneven distribution of the airflow field in the forming area was responsible for the excessive accumulation of smoke and spatter during the forming process. Through simulation-based optimization, significant improvements were achieved in the distribution of the airflow field, which were further validated through experimental verification. The use of the optimized structure in density experiments on test specimens also resulted in substantial enhancements.

Key words: Selective Laser Melting (SLM), airflow field, waveform air inlet duct, optimization simulation