Colloquia

Summary

Laser cladding is a process where powder is injected into a focused laser beam using an inert gas, forming a deposit referred to as a clad track. When cladded tracks are laid down next to each other, they form a continuous coating on a substrate material. The size and morphology of the solidified microstructure of the cladded tracks are closely linked to the size and shape of the laser-induced melt pool during the process.

In this research, an Optical Coherence Tomography (OCT) system is introduced to the laser cladding setup to investigate its ability to capture the characteristics of the melt pool. OCT is a non-invasive measurement technique that utilizes low-coherence light to create interference patterns. The interference pattern is used to obtain depth-resolved images. The effectiveness of the OCT sensor, both ex-situ and in-situ, was evaluated by benchmarking it against confocal microscopy and thermal imagery, respectively.

The study found that the in-situ OCT measurements reveal different zones with a distinguishable boundary, which is suggested to represent the liquid-solid phase transition from the melt pool to the solidified track.