STTR Phase I: Laser Ultrasonic Emission Sensor for In-process Monitoring during High-Speed Laser Welding

小型企业技术转移研究(STTR)第一阶段项目将展示在高速激光焊接薄板过程中对焊接质量进行在线监控的技术可行性，这对燃料电池制造至关重要。该监控系统基于激光对焊接过程中发射的微小超声波信号的检测。该技术是对基于激光的超声检测技术的改进。该技术使用高速激光焊接过程作为超声源，利用激光干涉仪连续监测熔池中产生的超声辐射，并对焊接质量进行评定。提出的激光焊接在线监测技术对于制造用于下一代节能交通工具的商用氢燃料电池至关重要。新的过程中监控技术将允许实时监控焊接质量，从而消除了对后处理检查的需求。其他大量使用激光焊接薄件的行业，如制药业，可能会从拟议的过程中传感器中受益。

The Small Business Technology Transfer Research (STTR) Phase I project will demonstrate the technical feasibility for in-process monitoring of welding quality during high-speed laser welding of thin plates which is critical to manufacturing of fuel cells. The monitoring system is based on laser detection of small ultrasonic signals emitted during the welding process. The proposed technique is a modification of laser-based ultrasonic inspection. In this technique, the high-speed laser welding process is used as the ultrasonic source and a laser interferometer is used to continuously monitor the ultrasonic emission generated at the weld pool and to assess the weld quality. The proposed in-process laser welding monitoring technique is critical for the manufacturing of commercial hydrogen fuel cells to be used in the next generation of energy efficient transportation vehicles. The new in-process monitoring technique will allow to monitor weld quality in real-time, suppressing the need for post-process inspection. Other industries where laser welding of thin parts is intensively used, such as the pharmaceutical industry, could benefit from the proposed in-process sensor.