激光粉末床熔融光学原位监测技术综述

In-situ monitoring techniques for laser powder bed fusion additive manufacturing:a review

激光粉末床熔融(LPBF)技术具有成形精度高、易于成形复杂结构零件的优点,已广泛应用于医疗、造船、航空航天等领域.然而由于成形过程复杂,激光粉末床熔融零件的缺陷通常难以控制,阻碍了该技术的进一步发展和应用.原位监测技术能够实时获取成形过程中零件的特征信息,为工艺参数的优化指明方向,提升零件的成形质量,是近年来研究的热点之一.总结了最近十年的相关研究成果,以粉末床、熔池及成形层三个监测阶段为线索,对比分析了多种针对激光粉末床熔融成形过程几何特征的光学原位监测技术,包括使用高分辨率工业相机、高速相机、条纹投影等监测方法的优点与不足,简要介绍了监测数据处理过程中用到的图像处理算法及机器学习方法,并展望了激光粉末床熔融原位监测技术的未来发展方向.

Laser powder bed fusion(LPBF)was easy to form complex structures with high precision,which had been widely used in medical,shipbuilding,aerospace and other fields.However,due to its complicated forming process,the defects of LPBF parts were hard to control,which hindered the further development and application of this technology.In-situ monitoring techniques could obtain the feature information of parts in real time,help to optimize process parameters,improve the forming quality,and made it become one of the research hotspots in recent years.The latest research in the last ten years was summarized.Based on the three monitoring stages of powder bed,melt-pool and fusion area,it compares the advantages and disadvantages of various optical in-situ monitoring techniques for geometric features,including the use of high-resolution industrial cameras,high-speed cameras,fringe projection and other monitoring methods.The image processing algorithms and machine learning methods used in monitoring data processing were briefly introduced,and the future development direction of LPBF in-situ monitoring technology was prospected.