Abstract
Laser metal deposition with wire (LMD-w) involves feeding metal wire through a nozzle and melting the wire with a high-power laser. With efficient process control, comprising sensing, processing and feedback correction of errors, the technology has a potential of changing the course of manufacturing. However, the limitation most often encountered in LMD is the difficulty in controlling the process. Monitoring and control of metal additive manufacturing processes has been mostly researched on powder-based systems, and has not yet been investigated to much extent on the side of metal wire feed arrangements. This work proposes a method for detecting cavities in a deposited layer in the LMD-w process via optical inspection and processing of images obtained from a high-resolution camera. The aim is to develop an effective sensing module which automatically detects discontinuities in each layer before proceeding to subsequent layers, to reduce part porosity and improve inter-layer bond integrity.
