Continuous wave Nd:YAG laser cladding modeling: A physical study of track creation during low power processing

This paper concerns the modeling of cladding using an Nd:YAG laser operating at low powers typically less than 800 W. Experimental observation of the evolution of the mass of the clads shows two power thresholds. The theoretical study relies on a calculation of the fluence provided to the substrate and on a model of heat transfer into the substrate. We suggest that the first threshold is the power required for substrate melting. The second power is the threshold when the powder is directly melted by the beam and is therefore a liquid when contacting the substrate.