Ultra-fast laser ultrasonic imaging method for online inspection of metal additive manufacturing

Ultra-fast laser ultrasonic imaging method for online inspection of metal additive manufacturingIn this paper, an ultra-fast laser ultrasonic imaging method is proposed to provide an efficient online monitoring of additive manufacturing (AM) processing. The innovations of the proposed ultrafast imaging method in this research mainly include two parts. Firstly, multi-circle combined scanning strategy and defect location algorithm is constructed to improve the detection efficiency. Secondly, a surface wave focusing algorithm (SWFA) is established to solve the problem of low SNR induced by rough surface signals.The highlights of the paper are:•The minimum detectable defect reaches 0.1 mm and the quantitative error could low down to 6.46% when the defect size is larger than 0.2 mm.•Compared with the C-scan imaging method, the method proposed in this paper can improve the scanning efficiency of single-layer inspection by more than 300%, which is meaningful to improve the efficiency of metal additive manufacturing.