Research Progress on Online Monitoring Technology for Metal Laser Additive Manufacturing
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摘要: 金属激光增材制造技术具备实现复杂构件高效精密成形的核心能力, 目前已经在航空航天、国防、医疗等重要工业领域得到了成功应用, 然而由于难以避免的存在较多的孔隙、裂纹等制造缺陷阻碍了其在高端装备中的更广泛应用. 制造过程的在线监测显得尤为迫切, 而高温、高速等极端的制造环境导致对原位监测与质量控制提出了跨学科挑战. 本论文综述了多维度检测技术体系构建, 梳理关键测试方法、技术的进展: 尤其光学、声学等主流传感技术以及多传感技术结合先进智能算法实现表面缺陷动态识别与内部缺陷特征提取的先进方法, 以及高速同步辐射成像等新兴手段为缺陷萌生、演化机制研究与检测方法探索提供了创新思路. 此外,梳理了基于多源数据融合建立微观熔池行为与宏观几何精度的协同分析框架方法, 以及基于在线监测的质量控制方法等进展. 受限于多源噪声干扰、多物理场信息同步检测效率不足等问题, 缺陷在线检测精度、速率、效率亟待提高. 分析认为: 未来研究需聚焦多传感探测技术与机器学习的深度协同, 继续探索更高效的在线智能检测方法, 以及注重数字孪生驱动的全流程质量预测模型构建, 以期为解决增材制造过程中缺陷监测与成形精度、质量控制的共性问题提供可靠的解决途径.Abstract: Metal laser additive manufacturing technology exhibits the capability for precision forming of complex components in high-end fields such as the aerospace industry. However, defects including thermal accumulation pores and high-stress cracks—caused by variations in power density and cooling rate—pose interdisciplinary challenges to in-situ monitoring and quality control. This paper reviews the establishment of a multi-dimensional detection technology system and systematizes the advancements in key testing methods and technologies. Specifically, mainstream sensing technologies, including optical and acoustic sensing, when integrated with advanced intelligent algorithms, facilitate dynamic identification of surface defects and extraction of internal defect characteristics. Multi-source data fusion further establishes a collaborative analysis framework linking microscopic molten pool behavior to macroscopic geometric accuracy. Additionally, emerging techniques, such as high-speed synchrotron radiation imaging, offer accurate cross-scale online observation tools for investigating the initiation and evolution mechanisms of defects. Current technologies are constrained by challenges such as multi-source noise interference and low synchronization efficiency of multi-physics field data. Future research should focus on the in-depth integration of multi-sensor detection technology with machine learning, explore online intelligent detection approaches, and develop full-process quality prediction models driven by digital twins. This study intends to provide theoretical synthesis and technical pathway analysis to address the common challenges of defect monitoring and forming accuracy control in the additive manufacturing process.
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图 1 金属增材制造系统示意图(廉艳平 et al. 2021). (a)LPBF技术制造系统, (b)LDED技术制造系统
图 2 LDED工艺下的典型缺陷类型. (a)平面度缺陷(Chen et al. 2021a), (b)熔融塌陷缺陷, (c)变形(Qiu et al. 2015), (d)开裂
图 3 不同的相机监测视角示意图. (a) LDED工艺下相机位置固定的欧拉视角(Hao et al. 2020), (b) LDED工艺下相机跟随激光器运动的旁轴拉格朗日视角(Feng et al. 2022b)
图 4 (a)同轴相机的熔池监测装置及熔池几何特征(Da Silva et al. 2023), (b)熔池信息的处理流程: 基于深度学习的熔池分割(Yang et al. 2025)
图 5 基于光学检测的双波段比色测温法获取熔池温度场流程示意图.(a)双波段分光光路(Hao et al. 2020), (b)基于DIC的双波段图像匹配方法(Ma et al. 2022), (c)温度场测量结果(Hao et al. 2020)
图 6 (a)基于温度场相似性(TDSD)的缺陷原位检测(Feng et al. 2022b), (b)基于光电二极管的熔池温度时间序列检测及(c)基于深度学习的激光粉末床熔融中连续缺陷检测(Mao et al. 2023)
图 7 基于声发射传感器的检测设备. (a)用于LPBF工艺的装置及信号(Kononenko et al. 2023), (b)布置于舱室内的麦克风装置(Yamashita et al. 2025)
图 8 麦克风检测设备. (a)用于LDED工艺的麦克风检测示意图(Ansari et al. 2025), (b)用于LPBF的麦克风检测装置(Chen et al. 2023d)
图 9 多传感器检测系统检测流程示意图. (a)用于LDED工艺的多传感器监测系统: 同轴相机和麦克风监测(Ren et al. 2025), (b)(d)基于深度学习方法的熔池图像与声信号的融合,(c)用于LPBF工艺的麦克风、相机监测设备(McKinney et al. 2025)
图 10 在线质量监测与控制. (a)自适应控制算法及温度、冷却速率控制结果(van Blitterswijk et al. 2025), (b)高度偏差的在线监测及缺陷矫正(Feng et al. 2025b)
表 1 工艺特征及监测策略差异
对比项 激光粉末床熔融 (LPBF) 激光定向能量沉积 (LDED) 能量与热物
理特征能量密度与尺度 低功率 (<1 kW), 微细光斑 (70-200 μm), 高能量密度 (10^6-10^7 W/cm2) 高功率 (1-10 kW), 大光斑 (0.6-6 mm), 较低能量密度 (10^4-10^5 W/cm2) 热动力学行为 极快瞬态: 冷却速率极高 (10^5-10^7 K/s), 熔池寿命短, 易发生匙孔失稳 高热惯性: 冷却较慢 (10^2-10^5 K/s), 存在显著的层间热积累与宏观热变形 缺陷类型与机制 主要缺陷形式 微观随机缺陷: 匙孔气孔、球化、微裂纹 宏观几何缺陷: 未熔合、几何形貌塌陷、宏观裂纹与变形 监测信号策略与对应算法 光学视觉 双轨并行策略:
高频微观: 10 kHz 高速相机捕捉微秒级匙孔/飞溅动态 (Ren et al.);
低频层析: 光学层析 (OT) 长曝光记录全层热辐射历史 (Ero et al.)低频宏观监测:
100 Hz 即可满足熔池形貌与轨迹监测; 同轴监测需克服粉末流遮挡与喷嘴限制, 常需配合旁轴红外声学信号 高信噪比结构声: 环境相对安静, 利于捕捉裂纹萌生及匙孔破裂的高频应力波 强噪声环境: 受送粉气流及机械臂运动噪声干扰严重, 信号成分复杂, 需强鲁棒性降噪 表 2 数据驱动与物理信息人工智能方法在增材制造过程监测的应用对比
比较维度 纯数据驱动 AI 物理信息约束 AI 核心机制 建立输入 (传感器信号) 与输出 (缺陷/性能) 之间的非线性映射, 依赖统计关联. 将物理偏微分方程 (PDEs) 作为损失函数或特征约束, 引导网络学习符合物理规律的解. 数据需求 高: 依赖大量高质量、带标注的实验或仿真数据 . 低: 物理定律提供先验知识, 可实现小样本甚至无监督学习. 可解释性 弱: 难以解释特征背后的物理意义. 强: 输出满足能量/质量守恒, 可反演物理参数. 泛化能力 弱: 对训练集分布外的数据适应性差, 需迁移学习 . 强: 物理定律具有普适性, 在不同工艺窗口下仍能保持较高精度. 典型应用 快速分类与预测: 缺陷识别、熔池图像分类、实时热历史预测. 场重建与机理分析: 温度场/应力场重建、路径规划、未见工况推演. 代表性工作 (Liu et al. 2025c, Skiadopoulos et al. 2026) (Rashid et al. 2025, Sajadi et al. 2025, Sharma and Guo 2025) 表 3 不同传感器的时空分辨率差异及应用场景
信号类型 传感器 空间分辨率
(缺陷尺度)时间分辨率
(数据频率)采集/处理延迟 应用场景/
可检测缺陷典型参考文献 光信号 高速相机 高
6–20 μm/pixel中/高
100 Hz – 100 kHz高
受限于海量图像数据处理, 难以实时闭环表面形态、球化、飞溅、铺粉异常 (Hooper 2018, Fischer et al. 2022, Zhang
et al. 2026a)光电二极管 无
单点积分信号, 无空间分辨能力极高
>100 kHz极低
微秒级响应, 适合实时控制熔池强度波动、过程失稳预警 (Mao et al. 2023, Webster et al. 2025) 热信号 基于比色法的相机 高
6–20 μm/pixel中/高
100 Hz – 100 kHz高
受限于数据采集和复杂的计算熔池温度场、熔池典型缺陷: 过熔、欠熔、飞溅 (Feng et al. 2022b, 2025a, b, Wang et al. 2026) 红外热像仪 中/高
像素级, 可识别 >25 μm 孔隙低/中
通常为低速, 少数能够高速采集中
需图像重建与特征提取熔池温度场分布、热积累、未熔合缺陷 (Estalaki et al. 2022) 声信号 麦克风 低
无空间信息, 需阵列定位高
20 Hz – 100 kHz低
数据量小, 处理快保护气流异常、裂纹形成、锁孔坍塌 (Gutknecht et al. 2021, Chen et al. 2023c) 声发射传感器 低
需接触式布置, 定位困难极高
MHz 级低 内部裂纹萌生、相变应力波、微孔隙 (Shevchik et al. 2018, Ito et al. 2021) X射线 同步辐射成像 极高
微米级极高
亚毫秒级极高
仅限离线分析, 数据量巨大熔池深处锁孔振荡、气泡演化机理研究 (Ren et al. 2023, Zhang et al. 2024) -
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