Online cracking detection by means of optical techniques in laser-cladding process

Additive manufacturing processes are advanced production methods used to build parts layer by layer or to repair components. One of the common limitations of this type of processes is the presence of defects that may cause failure of the part. In order to avoid this undesirable situation, quality control is essential. This is typically performed postprocess, once the part has been manufactured. However, online quality control systems would bring great benefits to detect the defects whereas they occur. In this work, a novel method is presented based on three online monitoring systems; thermal imaging and two different acoustic emission sensors. The results given by these methods are compared with traditional inspection procedures and validated by microscopic analysis. Results reveal the effectiveness of the procedure for detecting two different cracking mechanisms and also to determine values above which no layer cracking occurs.