Laser nitriding of titanium alloy in the atmosphere environment

This paper presents a laser nitriding technique for titanium alloys in atmosphere environment by using a specially designed nozzle. Instead of using a nitrogen-filled chamber, this technique allows performing laser surface nitriding in atmosphere. The major effort of this study was dedicated to the investigation on the gas dynamic factors that affect the nitriding results. Experimental results have shown that dynamic factors play an important role in laser nitriding. To prevent oxidation and achieve satisfactory and reproducible results, a high-pressure zone right above the laser irradiating region and a laminar flow should be maintained. Under this controllable flow condition it seems possible to extend the application of laser processing technique by using various gas/substrate or multi-gas sources.