Effect of laser power and powder flow rate on dilution rate and surface finish produced during laser metal deposition of Titanium alloy

The influence of processing parameters on the resulting properties of laser metal deposition process cannot be overemphasized. In this research, the influence of laser power and powder flow rate on the dilution and surface roughness value produced are critically studied.. The laser power was set between 1.8 kW and 3.0 kW, while the powder flow rate was set between 2.88 and 5.76 g/min. The scanning speed and the gas flow rate were maintained at constant values of 0.05m/s and 4l/min respectively. The study revealed that, as the laser power was increased, the degree of dilution increases but the average surface roughness value decreases. Also, as the powder flow rate was increased, the dilution decreases and the average surface roughness increases. The study shows that it is important to keep the powder flow rare low so as to achieve a better surface finished and also not to use too high laser power as this will result in higher dilution, which is not desirable in the laser additive manufacturing process because it will affect the dimensional accuracy of the part under processing.